Frequently Asked Questions: COVID-19 and Vaccines

COVID cells with a blue hue on a reddish background

What you need to know about the delta variant, additional doses, booster shots and more

We’ve gathered the information you need to protect yourself, your family and your community.


Quick links

Additional doses, booster shots and off-label shots

There is no need to call OHSU clinics about additional doses, booster shots or off-label shots. OHSU will share information here as it becomes available.

Additional vaccine doses: The Food and Drug Administration has authorized a third dose of the Pfizer and Moderna vaccines for people with weakened immunity. OHSU is contacting eligible patients. Pharmacies at OHSU (Pfizer only) and in the community have doses. Additional doses of the Johnson & Johnson vaccine are not yet approved. Learn more about additional doses.

Vaccine booster shots: The FDA and the Centers for Disease Control and Prevention have authorized booster shots of the Pfizer vaccine for people at high risk of severe illness and exposure. OHSU will offer boosters to qualified people  starting Sept. 27. Find a booster shot and learn more about booster shots.

Off-label shots: The FDA gave the Pfizer vaccine full approval for ages 16 and older (Pfizer is approved for ages 12-15 under emergency authorization). Though providers may now use the vaccine “off-label” (without specific FDA approval), OHSU is not offering off-label shots. OHSU will offer shots for children younger than 12 when the FDA approves them. Learn more about children and vaccines.

Fast facts about COVID-19 and vaccines

  • OHSU is contacting patients with weakened immunity who are eligible for an additional dose of the Pfizer or Moderna vaccine.
  • The FDA and CDC have authorized booster shots of the Pfizer vaccine for people at high risk of severe illness or exposure.
  • OHSU will offer booster shots to those who qualify.
  • Booster shots are not yet authorized for people who received the Moderna or Johnson & Johnson vaccines.
  • OHSU is not yet offering shots for children younger than 12.
  • Not all additional doses are booster shots. For those with weakened immune systems, an additional dose is part of getting fully vaccinated.
  • The FDA has given the Pfizer vaccine full approval for ages 16 and older, giving providers more leeway in how it’s used. OHSU is not offering "off label" shots, however.

See more in the additional doses/booster shots section.

  • The delta variant spreads more easily than previous forms of the coronavirus. It is about as contagious as chickenpox.
  • It was identified in India in December 2020 and in the U.S. in March 2021.
  • It is now the dominant global variant.
  • It may cause more serious illness than previous forms of the coronavirus.
  • Vaccinated people rarely get seriously ill, but they can carry and spread the variant to others.

See more in the delta variant section.

  • Because the coronavirus spreads in the air, masks protect against infection.
  • In Oregon, masks are required in indoor public spaces and in many outdoor public spaces.
  • OHSU recommends wearing a mask outside if you can’t stay 6 feet from others.
  • U.S. health officials have advised people to wear masks again as the delta variant spreads.

See more in the masks section.

  • The Pfizer vaccine is approved for children ages 12 and older. It is safe and effective.
  • OHSU recommends that your child be vaccinated as soon as they are eligible.
  • OHSU is not giving the Pfizer vaccine to children younger than 12. The FDA gave full approval to the vaccine for ages 16 and older, which allows for "off label" uses. However, OHSU is waiting for specific FDA authorization for age groups under 12. 
  • The Pfizer vaccine could be available for ages 5-11 as soon as October.

See more in the children and COVID-19 section.

  • Monoclonal antibody therapy is not a substitute for vaccination.
  • OHSU offers the therapy for those who meet strict criteria, including testing positive for COVID and being at high risk of severe illness.
  • The FDA granted emergency authorization for specific uses.
  • In studies, the therapy reduced the risk of severe illness.

See more in the monoclonal antibody therapy section.

  • COVID-19 is the illness caused by the coronavirus.
  • The World Health Organization declared COVID-19 a pandemic on March 11, 2020. The coronavirus has infected 231 million people worldwide, including 43 million in the U.S.; 4.7 million have died, including 687,000 in the U.S.
  • The coronavirus spreads through the air, in respiratory droplets from coughs, sneezes, shouting, singing, talking and breathing.
  • Getting vaccinated, wearing a mask and limiting interactions with people you don’t live with are the top ways to protect yourself.

See more in the COVID-19 section.

  • Vaccines are safe and effective. Tens of millions of Americans have gotten a vaccine under extensive safety monitoring. 
  • Every Oregonian age 12 and older is eligible for a vaccine.
  • Vaccines are free of charge.
  • If you missed the recommended time frame for your second dose, schedule it as soon as you can. There is no maximum time between doses.
  • If you lost your vaccine records, you can replace them.

See more in the vaccines section.

Additional doses/booster shots FAQ

Additional dose: When someone with a weakened immune system gets an additional dose of vaccine, it is not a booster. It is part of the first series of shots needed for the person to be fully vaccinated. Many people with impaired immunity did not have a full response to their first doses.

Booster shot: An additional dose is a booster when someone had a full response to vaccination, but effectiveness wanes over time. The booster re-energizes their immune response.

The FDA has authorized a third dose of the Pfizer or Moderna vaccine for some people with weakened immune systems. 

Shots are available to people who have had an organ transplant or who have similarly impaired immunity. This could include people in cancer treatment or taking medications to suppress immunity. 

Data shows that vaccines have been less effective in people with weakened immune systems. This has made them more likely to have a breakthrough infection (getting COVID-19 after vaccination).

About 7 million U.S. adults (about 2.7%) have impaired immunity. This means their body can't fight infection well. Compared with other people, they are more likely to get severe illness from COVID-19. They are also more likely to spread the virus to others in their household.

The FDA is allowing third Pfizer and Moderna doses under expanded emergency authorizations. The Pfizer vaccine can be given to people ages 12 and older, Moderna to ages 18 and older.

The shots are considered safe.

Because of a lack of data, the FDA has not approved a second dose of the one-dose Johnson & Johnson vaccine. If you had this vaccine and have a weakened immune system, OHSU recommends that you talk with your doctor. Your doctor can talk with you about whether you should get the Pfizer or Moderna vaccine.

Thousands of OHSU patients with impaired immunity qualify for an additional dose. OHSU is contacting patients we think would benefit from a third dose.

OHSU cannot provide these shots in clinics right now. OHSU pharmacies, which have the Pfizer vaccine, and community pharmacies may be able to provide a shot if you qualify as immunocompromised. You do not need a prescription or note from a doctor.

If you qualify for an additional dose because you have weakened immunity: Wait to get a third shot of the Pfizer or Moderna vaccine until it's been at least 28 days since your second shot.

The FDA and CDC have authorized booster shots for people at high risk of severe illness or exposure. See this booster shot fact sheet  to learn who qualifies.

The Biden administration had announced that booster shots would be available to the public, but health experts concluded that most people don’t need one.

It’s important to know that for most people, COVID-19 vaccines are doing an excellent job of preventing severe illness or death from COVID-19. The virus is spreading and causing a crisis mostly because of unvaccinated people, not people who haven’t had boosters.

Find a booster shot.

For most people, vaccines are doing what they were designed to do: keeping people from getting severely sick or dying. As the delta variant surges across the U.S., those falling seriously ill are overwhelmingly unvaccinated.

  • A CDC study released Sept. 10 found that unvaccinated people were more than 10 times as likely to die or need hospital care for COVID than fully vaccinated people. The study data came from more than 615,000 cases in April-July. 
  • CDC Director Rochelle Walensky said in July that more than 97% of people entering hospitals with COVID had not been vaccinated. At OHSU, 91% of those in the hospital and 97% in the ICU and on a ventilator in mid-September were not fully vaccinated.
  • A CDC study published Aug. 24 looked at more than 43,000 COVID infections in Los Angeles County from May 1 to July 25 among people 16 and older. It found that unvaccinated people were five times more likely to be infected and 29 times more likely to need hospital care compared with those who were fully vaccinated.
  • A CDC study looked at 1,100 people who received two doses of Pfizer or Moderna. The study, published Aug. 18, found that the vaccines’ ability to keep people out of the hospital stayed strong after six months, even as the delta variant spread.

Other studies suggest vaccines do a good job of preventing serious illness, even against the delta variant. They found vaccines do lose some effectiveness over time, but mostly among older people. 

  • A Pfizer study released in July but not yet peer-reviewed found that protection against serious illness and death held strong after six months. The large study (about 42,000 participants) did find that the vaccine’s protection against becoming infected with symptoms did dip. 
  • Data from Israel in August on the Pfizer vaccine suggest waning effectiveness for people ages 65 and older who got their second dose in January or February.
  • A CDC study in New York published Aug. 18 found that vaccines’ ability to keep people out of the hospital held steady. But the study found a dip, from 92% to 80%, in their ability to prevent people from getting COVID.
  • Another CDC study published Aug. 18 used data from thousands of nursing homes as the delta variant took hold. It found that the Pfizer and Moderna vaccines’ ability to prevent infections among residents fell from 75% in March-May to 53% in June-July.

Additional doses:

Health experts recommend that you get a dose of the same vaccine you had before. So if you had two doses of the Moderna vaccine, you would get a third dose of Moderna.

If that’s not possible, it’s OK to get a third dose of a vaccine of the same type. Both Pfizer and Moderna are mRNA vaccines, so you could follow two doses of Moderna with one of Pfizer.

If you had the Johnson & Johnson vaccine, OHSU recommends that you talk with your doctor.

It’s important to know that no shot is tailored to the delta variant. Research is underway to determine whether the type of shot matters.

Booster shots: 

The FDA and CDC have authorized booster shots of only the Pfizer vaccine and only for people who had Pfizer to begin with.

The agencies are still looking at data on the need for boosters for people who had the Moderna or Johnson & Johnson vaccine. Until OHSU has more guidance, we will offer booster shots only to people who have had two doses of Pfizer.

The FDA has granted full approval to the Pfizer vaccine for ages 16 and older. Before, all vaccines were in use under FDA emergency authorization.


  • Pfizer: 
    • This vaccine has full approval for use in ages 16 and older.
    • It has emergency authorization for use in ages 12-15.
    • It  has emergency authorization for third doses in people 12 and older with impaired immunity.
    • It has emergency authorization for booster shots for people at high risk of severe illness or exposure.
  • Moderna: This vaccine has emergency authorization for use in ages 18 and older, and for third doses for people 18 and older with impaired immunity.
  • Johnson & Johnson: This vaccine has emergency authorization for use in ages 18 and older. 

What’s the difference between emergency authorization and full approval? 

The FDA granted emergency authorization to three vaccines after reviewing data from large clinical trials. The trials, with tens of thousands of participants, showed the vaccines are safe and highly effective.

Full approval involves reviewing much more data from over a longer time. The FDA’s Peter Marks, director of the Center for Biologics Evaluation and Research, told The Washington Post the agency would review hundreds of thousands of pages, up from tens of thousands. The FDA also planned to inspect facilities where vaccines are made.

What does full approval mean for providers, patients and additional doses or booster shots? 

Under emergency authorization, providers must use a medication exactly as directed. That means providers are not free to give an additional vaccine shot unless the FDA specifically allows it. So far, the FDA has authorized additional doses of Pfizer and Moderna for some people with impaired immunity, and booster shots of Pfizer for people at high risk of severe illness or exposure.

Under full approval, providers may use a medication “off-label,” or in ways that are responsible but not specifically outlined. That means providers have the ability to provide an additional vaccine dose without the FDA specifically saying it’s OK. (OHSU is not offering off-label shots.)

It’s a good idea to take steps to prevent infection. The delta variant is easier to spread than earlier forms of the coronavirus.

OHSU advises everyone to:

  • Wear a mask indoors with people outside your household. A mask provides extra protection, including against the delta variant. 
  • Wear a mask outdoors if you can't stay 6 feet from others.
  • Limit gatherings. If you do gather, do it outside.
  • Stay 6 feet from others whenever possible.
  • Limit interactions with others. Keep distance between your unvaccinated child and other people in public.

If you are unvaccinated, OHSU recommends:

  • Get vaccinated. It's still possible to be infected with COVID-19 after vaccination, but you will be much less likely to become seriously ill or to need hospital care.
  • If you’re an unvaccinated adult, stay home and limit community interactions as much as possible.

Yes. You should continue following safety recommendations after a third or additional dose. That means:

  • Wear a mask in public.
  • Stay 6 feet away from people you don’t live with.
  • Avoid crowded and poorly ventilated spaces until your provider says otherwise.

OHSU strongly encourages you to get vaccinated.

In Oregon, masks are required in indoor and many outdoor public spaces. OHSU also encourages everyone to  consider wearing a mask outdoors when you can’t stay 6 feet from others.

No. For people who do not have impaired immune systems, being fully vaccinated means it has been at least two weeks since:

  • A second dose of the Pfizer or Moderna vaccine
  • One dose of the Johnson & Johnson vaccine

No. OHSU does not recommend testing to check the level of antibodies in your blood. Health experts do not yet know the level needed to prevent infection.

Delta variant FAQ

The delta variant is a newer form of the coronavirus. Viruses change (mutate) over time. A new form is called a variant.

The World Health Organization and U.S. officials are tracking variants. They include “variants of concern,” such as delta, and “variants of interest.”

For public ease, the WHO names some variants after Greek letters. Variants also have scientific names; delta’s is B.1.617.2.

Yes. It is about twice as contagious as previous forms of the coronavirus, and about as contagious as chickenpox.

An infographic that gives a visual comparison between the contagiousness of the original COVID-19 strain and the Delta variant.

Evidence suggests that it is, the CDC says. A study in Scotland found that people infected with delta were about twice as likely to need hospital care as those infected with an earlier variant. Studies in Canada and Singapore also found evidence of more serious illness.

The delta variant spreads much more easily than previous forms of the coronavirus. 

COVID-19 cases are surging. In late June, the U.S. saw days with fewer than 10,000 new cases. In late August, daily counts were as much as sixteen times that. Oregon has also seen cases multiply. Hospitals are seeing spikes in COVID patients.

Vaccinated people can carry and spread the delta variant. Unlike with earlier forms of the virus, vaccinated people can carry high levels of delta in their nose and throat. They can also spread it. This is why Oregon returned to requiring masks indoors and now also requires masks in many outdoor public settings. It's also why the CDC changed its advice and now advises everyone to wear masks in indoor public settings in areas with “substantial” or “high” spread.

The delta variant may cause more severe illness.

Symptoms are similar among most variants, according to the CDC. They include shortness of breath, fever, cough, and new loss of taste or smell.

Much is unknown, and research is underway. But early data suggest:

  • Symptoms may be more severe with the delta variant. Studies in Scotland, Canada and Singapore suggest that delta causes more severe illness.
  • Symptoms may vary for those who are fully vaccinated compared with those who aren’t.

Researchers are following data from millions of users of a COVID Symptom Study app launched by a London-based health science company. A lead researcher in July reported that:

Vaccinated people were most likely to report, in this order:

  • Runny nose
  • Headache
  • Sneezing
  • Sore throat
  • Loss of smell

Unvaccinated people were most likely to report, in this order:

  • Headache
  • Sore throat
  • Runny nose
  • Fever
  • Cough

Learn more:

Get vaccinated: The vaccines available in the United States offer excellent protection against severe illness and death from the coronavirus, including delta. The CDC director, Dr. Rochelle Walensky, said in July that more than 97% of people entering hospitals with COVID were unvaccinated. Find a vaccine.

Get your second shot: If you got a first shot of the Pfizer or Moderna vaccine but missed the recommended timeframe for a second shot, you can still get it.  There’s no time limit on getting your second shot. It will increase your protection.

Wear a mask:

  • Oregon requires masks in all indoor public spaces and many outdoor public spaces for everyone older than 5; and on public transit for those older than 2. 
  • OHSU officials recommend wearing a mask indoors in all public spaces or with people from outside your household; and outdoors when you can't stay 6 feet from others.
  • The CDC recommends wearing a mask in indoor public spaces anywhere the virus spread is “substantial” or “high.” That now means most of the U.S.

The delta variant was first identified in December 2020 in India, where it caused a devastating outbreak.

The variant was detected in the United States in March 2021. As of August, the CDC estimated that it accounted for more than 80% of U.S. cases. It is also the dominant form of the coronavirus globally.

Yes. Of 469 people infected in a delta-fueled outbreak in Massachusetts in July, 74% were fully vaccinated . A study of the outbreak also found that vaccinated people could carry the virus in their nose and throat, and spread it to others.

The CDC recommended mask-wearing in public again, even for those who are vaccinated, partly because of this data.

You are much less likely to become seriously ill if you are vaccinated. Wearing a mask in public indoors — and outdoors, when you can’t stay 6 feet from others — will help protect you and those around you.

OHSU's COVID tests show whether you have COVID, but not what variant. An additional test to sequence the virus can tell the variant, but it takes several days. Most labs don't sequence all tests; some samples are sequenced to estimate the prevalence of variants in the community.  

In any case, if you get COVID, it’s highly likely it’s the delta variant. It’s the most common form of the coronavirus in Oregon and across the U.S.

Regardless of which form of the virus you were infected with, recommendations for treatment and isolating yourself from others are the same. Sequencing might become more common if treatment recommendations change with the type of COVID.

The World Health Organization has identified thousands of coronavirus variants. Only a tiny portion have changes (mutations) that affect how the virus behaves. The WHO names some variants after Greek letters, in addition to their scientific names, to make them easier to talk about.

The WHO and the CDC created three categories to track variants, from least concerning to most:

  • Variants of interest: These variants have changes that scientists know or predict will affect traits such as how easily the virus spreads or how sick it makes people. Variants in this group are: eta, iota, kappa, lambda and mu.
  • Variants of concern: These variants have shown evidence of changes that make them more contagious or more severe. They may spread more easily, be better at getting past vaccines, or cause illness that’s harder to treat. Variants in this group are: alpha, beta, gamma and delta.
  • Variants of high consequence: There is no variant is in this category. A variant here would be able to evade tests and vaccines, cause severe illness and/or resist more than one therapy.

Learn more:

Masks FAQ

Officials have revised mask rules and recommendations for everyone, including those who are vaccinated, as the delta variant spreads.

  • Oregon requires masks in indoor and many outdoor public spaces for people 5 and older; and on public transit for ages 2 and older. 
  • OHSU recommends wearing a mask indoors in all public spaces or with people from outside your household; and outdoors when you can't stay 6 feet from others.
  • The CDC recommends that people wear a mask in indoor public settings in areas with “substantial” or “high” spread. Check spread levels by county.
  • The CDC says people with weakened immune systems or at higher risk of severe illness might want to wear a mask indoors regardless of the area's level of spread. The same applies if you live with someone at higher risk.

It’s also important to know:

  • OHSU hospitals and clinics have continued requiring masks for everyone ages 2 and older; see our visitor policy on our Coronavirus Resources page.
  • You need to follow local rules on masks, including guidance for workplaces and businesses. Some businesses may ask that you wear a mask.

If you are not fully vaccinated: The CDC lists ways to protect yourself and others from COVID-19. They include wearing a mask in public places and staying 6 feet from others. OHSU experts asks that unvaccinated adults stay home and limit community interactions as much as possible.   

Learn more:

Photo of a disposable mask on a model; there is a knot tied in the ear loops to make the mask fit snug over the face.
The CDC recommends tying a knot in a disposable mask’s ear loops to make it fit against the face.

The CDC updated mask recommendations after research showed these options can greatly increase protection.

Be sure your mask fits snugly:

  • Be sure it has no gaps that can let droplets in or out.
  • Use a mask with a nose wire and shape it to fit.
  • Use a mask fitter or brace to hold a disposable mask in place.

Add layers. Be sure you can breathe easily:

  • Wear a cloth mask with more than one fabric layer.
  • Or wear a disposable mask under a cloth mask.


  • Don’t wear two disposable masks. They don’t fit tightly, and adding a second one won’t help.
  • Don’t wear a second mask with a KN95 mask. KN95 masks should be worn alone.

In many cases, yes.

  • Oregon requires masks for everyone 5 and older in indoor and many outdoor public spaces to protect against the highly contagious delta variant.
  • OHSU also recommends that you wear a mask indoors with people you don't live with, and outdoors when you can't stay 6 feet from others.

You should also wear a mask:

  • If required under local rules, including guidance for workplaces and businesses, and if a business asks you to.
  • On public transit and at travel hubs such as airports and bus stations.
  • When going to the doctor, and at hospitals and long-term care facilities. (Masks are required at OHSU hospitals and clinics, for example.)
  • In group settings such as homeless shelters, jails and prisons.

Children and COVID-19 FAQ

Yes.  Right now, the Pfizer vaccine is the only COVID-19 vaccine authorized for children 12 and older. It is safe and effective. The FDA and CDC authorized the Pfizer vaccine for children ages 12-15, and fully approved it for people 16 and older after rigorous study. 

The CDC strongly recommends that people 12 and older get vaccinated. Experts from Oregon, Washington and California reviewed the data and agreed with the FDA and CDC’s conclusions.

Pfizer announced Sept. 20 that clinical trials showed its vaccine is safe and produces a strong immune response in children ages 5-11. Moderna is also testing its vaccine in this age group, and both companies have trials underway to test vaccines in children as young as 6 months. See “When will vaccines be available for children younger than 12?” below to learn more.

Learn more:

The Pfizer vaccine could be available for ages 5-11 as early as October. The company announced Sept. 20 that results from clinical trials in this age group showed a low dose is safe and produces a strong immune response.

The company expects to apply for FDA authorization by the end of September, putting the vaccine on track to be available for ages 5-11 around Halloween.

For now,  Pfizer’s vaccine is authorized for ages 12 and older. Vaccines by Moderna and Johnson & Johnson are authorized for ages 18 and older.

Here’s what else we know:

  • Pfizer expects to have data from clinical trials for children younger than 5 by the end of the year.
  • Moderna is also testing its vaccine in children as young as 6 months old. It expects to have some results by year's end. Johnson & Johnson is testing its vaccine in ages 12-17.
  • Pfizer and Moderna agreed in July to expand their trials so the FDA can better assess the risk of rare heart conditions linked to mRNA vaccines. None of the nearly 2,300 children in Pfizer's trial for ages 5-11 developed this complication. Two-thirds received the vaccine, and one-third a saltwater shot.

Yes. When a vaccine is approved for your child’s age group, that means studies show it is safe and effective. COVID-19 vaccines have been used under the most intensive safety monitoring in U.S. history. Your child cannot get COVID-19 from any COVID-19 vaccine.

Yes. Children with compromised immune systems are at higher risk of severe illness from COVID-19. A vaccine is the best way to protect them.

COVID-19 vaccines currently available in the U.S. are not live vaccines. This means they are safe for people with compromised immune systems. We encourage you to get your child vaccinated as soon as a vaccine is available for their age group.

No. The FDA has fully approved the Pfizer vaccine for people ages 16 and older. Providers sometimes give medications to children “off-label.” This means the medical provider prescribes a medication, to benefit their patient, in a way that is different from how it is specifically approved.

The American Academy of Pediatrics discourages off-label use of the Pfizer vaccine for children younger than 12. OHSU is following this advice. We need to wait for results of vaccine trials in children under 12 to make sure the vaccines are safe and effective. These trials may lead to doses and schedules that are different in children than in adults. 

We know many families are eager for a vaccine for young children. We are, too, and will be ready to give vaccines once the FDA grants emergency-use authorization for children under 12.

Because of the highly contagious delta variant, the CDC recommends all students in K-12 schools wear masks. Oregon also requires that people 5 and older (2 and older on mass transit) wear masks in indoor and many outdoor public settings.

Wearing a face mask is safe for all children 2 years of age and older, with rare exceptions. Face masks:

  • Do protect your child from others who may have the coronavirus.
  • Do help prevent the spread of the coronavirus, especially since most children are not yet vaccinated.
  • Do not reduce oxygen intake or trap carbon dioxide.
  • Do not affect your child’s lung development.

For most children with health conditions, the benefits of wearing a mask outweigh any risk. Wearing a mask is safe, even if your child has:

  • Asthma, cystic fibrosis or other lung conditions
  • Rashes, sensitivity or other skin conditions

We understand that wearing a mask can be hard for young children and children with:

  • Autism or other sensory issues
  • Severe anxiety, PTSD (post-traumatic stress disorder), or behavioral issues

Helping your child learn to wear a mask is important for their health. Check out these tips from the Oregon Pediatric Society.

For more support, ask your child’s school to add mask-wearing as one of their educational goals. You can also talk with your child’s doctor for help.

Your child should not wear a mask if:

  • They are under age 2.
  • They have a condition, such as cerebral palsy, that makes them physically unable to remove their mask.

Yes. In Oregon, masks are required for ages 5 and older in indoor and many outdoor public settings, and for ages 2 and older on public transit. OHSU recommends wearing a mask outdoors any time you can't stay 6 feet from others.

Because of the highly contagious delta variant, the CDC also recommends that everyone ages 2 and older, even if vaccinated, wear a mask in public indoor settings in areas with “substantial” or “high” spread

The CDC has also recommended that teachers, staff, students and visitors to schools wear a mask indoors, regardless of vaccination status.

Children have similar side effects to the vaccine as adults. Just like in adults, mild side effects are normal signs that your child’s body is building protection against the infection the vaccine is targeting.

Some children have no side effects. For those who do, they should go away within a few days. The most common side effects are:

  • Pain, redness or swelling on the arm where they got the shot
  • Tiredness
  • Headache
  • Muscle pain
  • Chills
  • Fever
  • Nausea

If exposed to COVID-19, children have a similar risk of infection as adults. Infected children are less likely than adults to be severely ill, and more likely to have mild symptoms or no symptoms.

Regardless of age, children who have medical conditions such as chronic lung disease or cardiac disease, or who have impaired immunity, are at risk of severe sickness if infected with COVID-19.

We are still learning about the long-term effects of COVID-19 in children. Your child’s risks are lower if they are vaccinated. That’s why we recommend they get a vaccine as soon as it’s available.

Yes. Children are more likely than adults to have mild coldlike symptoms or no symptoms when infected with the coronavirus. But studies have shown they can still spread the virus to others.

The symptoms of COVID-19 are similar in children and adults. However, children with confirmed COVID-19 usually have mild symptoms. Common symptoms in children include:

  • Fever
  • Runny nose
  • Cough
  • Vomiting
  • Diarrhea

Some children have more severe symptoms, including trouble breathing, confusion and chest pain. If your child has any symptoms, talk to their health care provider.

Call your child’s health care provider if your child has a fever, cough, vomiting, diarrhea or just doesn’t feel well. Tell the provider if your child has been near someone with COVID-19. They can help you decide if your child should get tested for the coronavirus and how best to treat your child.

Watch for signs that your child might need more help. Go to the emergency room if they have:

  • Trouble breathing
  • Confusion, dizziness or difficulty staying awake
  • Chest pain or severe stomach pain
  • Cold, sweaty, pale or blotchy skin

There is not yet evidence that the delta variant causes more severe disease in children. It’s  being urgently studied.

However, the delta variant is much more contagious than previous COVID-19 strains. Young children, especially those who can’t yet be vaccinated, are at higher risk of infection than they were earlier in the pandemic. As more children get COVID-19, more will have severe disease and need hospital care.

Yes. The American Academy of Pediatrics recommends keeping and not delaying well-child visits for all ages (infants, children and adolescents). Vaccinations are essential to protecting all children against dangerous and preventable diseases such as measles, meningitis and whooping cough.

The AAP recommends:

  • All well-child visits should take place in person whenever possible, with the providers who have routinely seen your children.
  • Clinics who care for children should call families who have missed an in-person visit to reschedule.
  • Families should not delay visits to their child's doctors (pediatricians, family medicine or nurse practitioners and physician assistants.)
  • Children and youths who regularly see specialists should resume, and those who are referred to specialists should complete these visits.

The AAP says some well-child visits can start through a virtual visit (by video or phone) but that parts of these visits must be done in person. At Doernbecher clinics, we are doing well-child visits only in person.

Learn how OHSU keeps patients, visitors and staff safe.  

Monoclonal antibody therapy

Monoclonal antibody therapy is a treatment that uses lab-made antibodies to fight disease. The antibodies circulate in your blood, like antibodies made by your body’s immune system.

Monoclonal antibody medication for COVID-19 is given by IV or under the skin, under FDA emergency-use authorization. The antibodies target the coronavirus spike protein, blocking the virus from entering cells and spreading in your body.

Studies have shown it:

  • Reduces the risk of severe illness and hospitalization after infection.
  • Reduces the risk of developing COVID and symptoms after exposure.

The therapy is more effective the sooner it’s given.

Monoclonal antibody therapy is not a replacement for a vaccine. The FDA allows treatment only after a positive test or exposure, and only for those at high risk of severe disease.

No. Monoclonal antibody therapy is not a substitute for a vaccine. It can be used only after a positive test or exposure, and only for those at high risk of severe illness.

It does lower risk of severe illness after infection or exposure, but it is not a guarantee you won’t become dangerously ill.

In addition:

  • Monoclonal antibody therapy offers protection against COVID-19 for only a few weeks or months. Vaccines can last much longer.
  • Monoclonal antibody therapy can be used only after infection or exposure. Vaccines help protect you from getting the virus in the first place.
  • Monoclonal antibody therapy does not stop viruses from spreading and changing (mutating) into new variants. Only vaccines can end the pandemic.

OHSU strongly encourages you to get a vaccine. It’s the single best thing you can do to protect yourself and those around you.

The FDA allows monoclonal antibody therapy for people who have tested positive, if they:

  • Have mild to moderate symptoms that started less than 10 days before.
  • Are not in the hospital, and don’t need oxygen therapy for COVID.
  • Are 12 or older and weigh at least 88 pounds.
  • Are at high risk of severe disease because of:
    • Age (65 or older)
    • Weight (BMI over 25)
    • Pregnancy
    • Certain medical conditions, such as those listed by the CDC

The FDA allows therapy to prevent COVID in those who have been exposed, if they:

  • Are at high risk of severe disease.
  • Are 12 or older and weigh at least 88 pounds.
  • Are not fully vaccinated; or are vaccinated but have impaired immunity.

OHSU offers monoclonal antibody therapy for COVID-19 by IV and under the skin. To be eligible, you must:

  • Qualify under FDA guidelines.
  • Have tested positive for COVID-19. (OHSU does not yet offer the preventive therapy.)
  • Be a patient of OHSU or OHSU Health Hillsboro Medical Center, and have a referral from an OHSU or Hillsboro Medical Center provider.
  • Be at least one of the following:
    • Unvaccinated
    • Not fully vaccinated (only one dose of the Pfizer or Moderna vaccine)
    • Vaccinated with the one-dose Johnson & Johnson vaccine
    • Immunocompromised (with weak immunity from disease or treatment)

For questions about qualifying or making an appointment: Call our hotline at 833-647-8222.


OHSU does NOT recommend ivermectin to treat COVID-19. Merck, the maker of ivermectin, warns against using it for COVID-19. In addition, the FDA and National Institutes of Health have not endorsed using it for COVID-19. Clinical trials (tests on people) have not shown that it’s effective for COVID-19.

Ivermectin is approved for use in people and some animals to treat some parasites. Humans should never take medications meant for animals. Taking ivermectin in any unapproved way could also cause serious harm. 

Learn more:

Simply, the coronavirus is the virus, and COVID-19 is the illness it can cause.

The virus itself is called SARS-CoV-2, short for severe acute respiratory syndrome coronavirus 2. Coronaviruses are part of a large group of viruses. Some coronaviruses cause mild illness, such as the common cold. Others can cause serious illness.

An illustrative example showing various examples of people experiencing typical covid-19 symptoms
Infographic: Centers for Disease Control and Prevention

Symptoms can appear 2-14 days after exposure:

  • Fever or chills
  • Cough
  • Shortness of breath or trouble breathing
  • Fatigue
  • Muscle or body aches
  • Headache
  • New loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea

If you see emergency signs, call 911 or your emergency department. They are:

  • Trouble breathing
  • Persistent pain or pressure in the chest
  • New confusion
  • Inability to awaken or to stay awake
  • Bluish lips or face
  • Other severe symptoms

Coronavirus tests

These tests detect the virus itself. A sample is taken, usually by inserting a swab into the person’s nose to collect mucus. Tests on the sample show if there’s any genetic material from SARS-CoV-2, the virus that causes COVID-19.

The tests show if someone is infected with the coronavirus. If someone has symptoms, the tests can show that the coronavirus is the cause. 

Antibody tests

Antibody tests detect antibodies to SARS-CoV-2. Antibodies are tiny proteins that the body’s immune system releases into the bloodstream to fight infection.

If someone has antibodies, it means the person had enough exposure to the coronavirus to have an immune response, with or without symptoms. For this test, a person gives a blood sample. These tests are also called serum tests or serology tests.

OHSU recommends against getting an antibody test unless:

  • There is a clear medical reason.
  • There is a plan for how your health care provider will use the results.

OHSU also recommends against having an antibody test to:

  • Decide if you should get a COVID-19 vaccine.
  • Try to determine how you will respond to a vaccine.

Vaccines FAQ

All three vaccines spur the body to make antibodies that specifically fight the coronavirus. Antibodies are made by white blood cells and are part of the immune system — the body’s system to fight infection.

Pfizer and Moderna:

These vaccines send a snippet of genetic material from the coronavirus — instructions called messenger RNA or mRNA — into cells. The instructions tell the cells to make a harmless spike protein like the one on the coronavirus.

The body’s immune system recognizes that this protein doesn’t belong. It activates white blood cells to form infection-fighting antibodies. The immune system also remembers the spike protein, so it's ready to fight the real coronavirus should it enter the body.

Once the proteins are made, the body destroys the mRNA.

Johnson & Johnson: 

This is a viral vector vaccine. Specifically, it’s a type called an adenovirus vector vaccine or an adenovector vaccine.

Like the mRNA vaccines, the vaccine uses a snippet of genetic material from the coronavirus to tell cells to make spike proteins. The spike proteins activate the immune system.

In this case, instructions are in DNA delivered in a virus called an adenovirus. Normally, this virus causes the common cold. It is NOT the coronavirus.

The adenovirus is genetically altered. The virus cannot make copies of itself, and it cannot cause illness. The virus is just a carrier (vector). The DNA cannot change your DNA.

After vaccination with any of these vaccines:

  • If you contract the coronavirus, your immune system is better able to attack it, making you less likely to develop COVID-19.
  • If you do develop COVID-19, you will be less likely to become seriously ill.
  • Your immune system knows how to fight the coronavirus without having come in contact with it.

Learn more:

Learn how COVID-19 vaccines work, why OHSU experts are confident they’re safe, and why they recommend getting one.

To start your protection as soon as possible, you should be vaccinated as soon as possible. This means getting any of the vaccines that are available to you.

Visit our vaccines page to see which vaccines are offered at each OHSU vaccination site. You can also filter by vaccine in the CDC VaccineFinder tool. 

The Pfizer, Moderna and Johnson & Johnson vaccines have all been found to be highly effective. In addition, any new vaccine must be found to offer good protection against COVID-19 to win FDA emergency-use authorization or full approval. The FDA also continues monitoring vaccines to see how they perform.

All three vaccines are highly effective, health experts say. The three vaccines did report different efficacy rates, though, and you may have concerns about that.

Let’s take a look:

  • Johnson & Johnson reported an efficacy rate of 66%. Pfizer and Moderna reported rates of about 95%. The efficacy rate is the reduction in any severity of illness, during clinical trials, among those who got the vaccine compared with those who didn’t.
  • But health experts say the vaccines can’t be compared apples-to-apples. The vaccines were tested in different ways and at different times. Johnson & Johnson’s was tested later, for example, after more-contagious variants had emerged.
  • On the most important measures — preventing hospitalization and death — Johnson & Johnson had a 100% efficacy rate. That means no one who received the vaccine in clinical trials died or needed hospital care because of COVID-19. The Johnson & Johnson vaccine also had an 85% efficacy rate for preventing severe illness.

The Johnson & Johnson vaccine also offers some advantages:

  • It is one dose. That makes it convenient for anyone who would find it hard to attend two visits.
  • It does not need ultra-cold storage, making it an option for more areas.

Overall, health experts advise getting whichever vaccine is available to you first. Speed is especially important as variants spread.

Learn more: 

Dr. Dawn Nolt, an OHSU expert on infectious diseases, addresses the effectiveness of the Johnson & Johnson vaccine in a clip from a March 9 presentation.

Yes. If you got a first dose of the Pfizer or Moderna vaccine, it’s important to get your second shot. This makes sure that your vaccination is as effective as possible. Schedule your second dose as soon as you can. (The Johnson & Johnson vaccine is just one dose.)

It’s also important to know:

  • There is no maximum time between doses.
  • OHSU has no limit on how long after a first shot people can get a second.
  • OHSU recommends second doses:
    • 19-35 days after your first Pfizer dose (Pfizer recommends three weeks, or 21 days).
    • 25-35 days after your first Moderna dose (Moderna recommends four weeks, or 28 days).
  • The CDC updated its guidelines to recommend second doses — when a delay is unavoidable — up to six weeks (42 days) after the first dose.
  • Even if you miss all these windows, you don’t have to start over by repeating a first dose. Just get your second dose.
  • There is little data on how well mRNA vaccines (like the Pfizer and Moderna vaccines) work when the second dose is more than six weeks after the first. That means it’s not known whether waiting longer makes the vaccine more effective, less effective or causes no change.

Learn more:

Medical gloves are in short supply worldwide. Oregon would need millions of additional pairs if gloves were used for all vaccinations.

In addition, under Occupational Safety and Health Administration (OSHA) regulations, providers are not required to wear them for COVID-19 vaccinations. Except in special cases, providers can clean their hands between each recipient instead.

The CDC and the Advisory Committee on Immunization Practices agree that hand hygiene can replace glove use.

Learn more: 

The Reason Why Nurses Don’t Wear Gloves When Giving COVID-19 Vaccine Explained

Yes. It's possible to get COVID-19 again, which can result in serious illness. Experts also don’t know how long post-COVID immunity ("natural immunity") lasts.

The CDC says research does show that full vaccination offers better protection than natural immunity. A 2021 study of people in Kentucky who'd had COVID found that reinfection was more than twice as likely in unvaccinated people than in fully vaccinated people.

You will NOT be charged anything for a vaccine, and you do not need health insurance to get a vaccine.

If you do have health insurance, though, providers are allowed to charge your insurance company an administration fee. This fee may temporarily appear in your MyChart account as it is processed. You will NOT be billed.

Vaccine safety FAQ

Yes. The FDA approved the vaccines only after rigorous clinical trials (tests on people). Tens of millions of Americans have been vaccinated, and only a tiny fraction have had a serious complication. Health experts say the benefits far outweigh the risks.

The Pfizer vaccine has full FDA approval. Even to get emergency-use authorization, though, vaccines went through three phases of clinical trials involving tens of thousands of participants — far more than is typicalThis gave researchers a lot of data quickly on safety and effectiveness. Clinical trials also must follow rigorous rules for safety and oversight. 

In addition, the Moderna and Johnson & Johnson vaccines were developed with help from Operation Warp Speed. The program used federal taxpayer dollars to pay for research, development and millions of early doses. It’s one reason vaccines were ready to ship the instant they were approved.

The FDA, CDC and other government agencies have many systems to monitor the vaccines for any safety issues that didn’t turn up in clinical trials. They can act quickly if a problem is spotted. Tools include v-safe, which lets people use a smartphone to report any side effects to the CDC.

It's true that the vaccines were developed in months instead of years. But Dr. Anthony Fauci, the nation’s top infectious-disease expert, is among health officials who say speed did not sacrifice safety. “The speed was the reflection of extraordinary advances in the science of vaccine platform technology,” Dr. Fauci told ABC.

Learn more:

Although mRNA vaccines have not been widely used against an infectious disease before, researchers have used them for years in studies of the flu, Zika and other illnesses. They have also been used in cancer treatments. 

The mRNA vaccines for COVID-19 have been developed with the same rigorous standards applied to all vaccines.

Viral vector vaccines have been studied since the 1970s. Two Ebola vaccines are viral vector vaccines. The vaccines have also been used in clinical trials against viruses that include the Zika virus, HIV and flu viruses. 

In addition, all COVID-19 vaccines cleared for use in the U.S. were developed with the same rigorous standards applied to all vaccines.

No. The Pfizer, Moderna and Johnson & Johnson vaccines do not contain live virus. That makes it impossible to get COVID-19 from a vaccine.

No. DNA is in the nucleus of cells, protected by the nuclear membrane. The mRNA in the Pfizer and Moderna vaccines does not enter the nucleus, and it does not affect or interact with DNA. In addition, mRNA from a vaccine cannot be made into DNA that could change a person's DNA.  

The genetic material (DNA) in the Johnson & Johnson vaccine does enter the cell’s nucleus. But the cell only reads the instructions. The DNA cannot interact, alter or combine with your DNA.

The CDC investigated whether rare cases of myocarditis and pericarditis (inflammation of the heart muscle and surrounding tissue) are related to COVID-19 vaccines.

A small number of people nationwide have developed these conditions after getting an mRNA vaccine (the type made by Pfizer and Moderna).

It’s important to know:

  • Reported cases of myocarditis and pericarditis after vaccination are very rare.
  • Most cases are mild, treatable and leave no lasting effects. No one has died.
  • The benefits of getting vaccinated far outweigh the risks, according to the CDC and the Department of Health and Human Services.
  • The CDC and other health organizations strongly encourage those 12 and older to get vaccinated.

The CDC’s Advisory Committee on Immunization Practices met June 23. Health experts said:

  • There is a “likely association” between mRNA vaccines and mild inflammation of the heart muscle and surrounding tissue (myocarditis and pericarditis).
  • The CDC reported about 12.6 cases per 1 million vaccine doses.
  • The heart condition occurs mostly in younger males about a week after the second dose of an mRNA vaccine.
  • The FDA is adding fact sheets for the Pfizer and Moderna vaccines. The sheets will tell recipients to seek medical care if they have any symptoms related to these heart conditions.

Anyone with these symptoms should get medical care right away, regardless of whether they got a vaccine:

  • Chest pain
  • Chest tightness
  • Difficulty breathing
  • Heart racing

If you have questions or concerns about the vaccine or potential side effects, including myocarditis or pericarditis, talk to your primary care provider or another trusted health care professional.

Federal health officials stress that the benefits of the Johnson & Johnson vaccine far outweigh the risks.

The FDA has added warnings to the vaccine’s fact sheets for very rare complications. The updates are a reassuring sign that national vaccine safety monitoring is working well to identify potential complications.

Guillain-Barré syndrome:

In July 2021, the FDA added a warning of a higher risk of Guillain-Barré syndrome. This rare condition can damage nerve cells, causing muscle weakness and sometimes paralysis.

There were reports of 100 cases in the U.S. among nearly 13 million people who had received the Johnson & Johnson vaccine at that point. In most cases, symptoms began within six weeks of getting the vaccine.

Most people who develop the syndrome each year in the U.S. fully recover, though some have permanent nerve damage.

Blood clots:

The Johnson & Johnson vaccine was paused for 10 days in April after six women (the tally later rose to 15) developed dangerous blood clots.

The women, nearly all ages 18 to 49,  were among more than 8 million people who had gotten the vaccine at that point.

What should you do if you get the Johnson & Johnson vaccine?

  • See the fact sheet for people who get the vaccine. It outlines possible complications and when to seek care.
  • See the fact sheet for health care providers. It includes how to identify and treat adverse reactions.
  • Anyone who has health issues after getting a vaccine from OHSU can call our hotline at 833-647-8222.

Side effects and after-vaccination FAQ

You can expect mainly mild to moderate side effects such as:

  • Fatigue
  • Fever
  • Chills
  • Muscle aches and pains

In clinical trials, side effects tended to be higher after the second dose, and less for those older than 65.

Side effects can be managed with:

  • Rest
  • Drinking fluids
  • Fever-reducing medication, such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin)

Call your health care provider if you have side effects that bother you or that don't go away.

Learn more:

Possible Side Effects After Getting a COVID-19 Vaccine, CDC

Call 911 or go to the nearest hospital if you have a severe allergic reaction such as:

  • Swelling of the throat and mouth
  • Trouble breathing
  • Lightheadedness
  • Confusion
  • Blue skin or lips
  • Fainting

Call your health care provider if you have side effects that bother you or that don’t go away.

Learn more:

What to Do If You Have an Allergic Reaction After Getting a COVID-19 Vaccine, CDC

Health officials are tracking side effects as part of widespread efforts to monitor vaccine safety. You can report side effects to:

  • The FDA/CDC Vaccine Adverse Event Reporting System (VAERS): Visit the VAERS website or call 1-800-822-7967.
  • V-safe: Learn how to use the CDC’s v-safe smartphone tool.

Pregnancy, breastfeeding and women's health FAQ

The CDC recommends that you get vaccinated. The agency says growing evidence suggests that the benefits of being vaccinated far outweigh any risks:

  • Data from vaccine-monitoring systems found no safety concerns among 35,000 people in their third trimester. Early findings were published in the New England Journal of Medicine.
  • A study found no increased risk of miscarriage among about 2,500 people who got an mRNA vaccine (such as Pfizer or Moderna) right before or during pregnancy.
  • Early data suggests that getting an mRNA vaccine during pregnancy reduces the risk of getting COVID-19.
  • Getting an mRNA vaccine during pregnancy builds antibodies that might protect the baby. Antibodies have been found in umbilical cord blood.

Research and safety monitoring is continuing.

Health experts have noted that pregnant people have:

  • A higher risk of serious illness if they get COVID-19.
  • A higher risk of premature birth or other pregnancy complications if they get COVID-19.

They also advise considering:

  • Your risk of being exposed to the coronavirus.
  • Whether you have any other medical condition that could put you at higher risk of serious illness from COVID-19.

Learn more:

COVID-19 Vaccines While Pregnant or Breastfeeding, CDC

The CDC recommends that all people ages 12 and older, including those who are breastfeeding, get vaccinated. OHSU experts recommend that you talk with your health care provider. 

There is no data on the safety of COVID-19 vaccines in people who are breastfeeding, in breast milk or in breastfeeding infants. Breastfeeding people were not part of clinical trials. The CDC says, though, that mRNA vaccines are not thought to be a risk to breastfeeding infants.

The American College of Obstetricians and Gynecologists recommends that vaccination be offered to people who are breastfeeding under the same guidelines as for people who aren’t.

Learn more:

COVID-19 Vaccines While Pregnant or Breastfeeding, CDC

For some people, getting a COVID-19 vaccine is followed by swelling in lymph nodes under the arm where they got the shot.

The swelling is a normal sign that your body is building protection against COVID-19. It could cause a false result on a mammogram, though. If you are due for a mammogram, we recommend that you:

  • Get your mammogram before your vaccine.
  • Or wait at least four weeks after your Johnson & Johnson vaccine, or after your second dose of the Pfizer or Moderna vaccine.

OHSU videos

See videos about COVID-19 vaccines and why OHSU experts want to make sure you get your shot.

Claim your shot

Learn why Dr. Donn Spight, an OHSU surgeon, is doing everything he can to make sure people of color are not left behind.

Benefits and risks

Dr. Dawn Nolt goes over vaccine studies, pluses and minuses so you can make a confident decision.

The facts on vaccines

Dr. Allison Empey is a pediatrician and the Wy’East director of the Northwest Native American Center of Excellence. She discusses why she believes in the COVID-19 vaccine.

Why they got vaccinated

Hear why Oregon health and community leaders got their vaccine.

Vaccines don’t affect DNA

Dr. Chris Evans, an OHSU infectious disease expert, shares why you don’t have to worry about vaccines affecting your DNA.

An Olympian’s take

Galen Rupp encourages fellow Oregonians to protect themselves and one another so we can all “enjoy our great state.”

Mexican/Latin community

Carlos Quesnel Meléndez, lead consul of the Consulate of Mexico in Portland, wants compatriots to know they can get a vaccine for free, without ID and without questions about immigration status.

Overcoming disparities

Learn why Multnomah County’s Charlene McGee is fighting disparities and working toward vaccine acceptance.

Resuming traditions

Learn what Mohamed Alyajouri, an OHSU practice manager and member of the Muslim community, looks forward to.

Simple mRNA explainer

OHSU’s Dr. Chris Evans breaks down how mRNA vaccines, like Post-it Notes, deliver quick instructions.

“Honest answers”

Learn why Jordan Kent, former play-by-play TV announcer for the Trail Blazers, encourages people to talk with the experts.

The day he got vaccinated

Hear why getting a vaccine gave longtime Portland activist Ray Leary “a good, warm feeling.”

“A resilient people”

Virginia Luka, Multnomah County Public Health’s program specialist senior for the Pacific Islander Community, shares why vaccines are important to her community.

What are your plans?

Community leaders and health experts look forward to gathering with family and friends, sharing favorite foods, and an “incredible sense of freedom.”

“We rise”

Apostle Levell Thomas explains why the Black community should claim their vaccinations.

Inside OHSU's ICU

"Overwhelmed," by KGW News

Soul 2 Soul event

“Really thrilled”; story and video by KATU

Dr. Donn Spight standing in the Robertson Life Sciences building

Learn how information from OHSU’s Dr. Donn Spight helped a Portland woman decide to get vaccinated.