COVID-19 Vaccine Frequently Asked Questions

Updated: December 20, 2021

We update this page as any new information develops. Please check regularly for updates by:

Q: How can I get the COVID-19 vaccine or a booster?

A: Many retail pharmacies offer vaccines, including the OHSU Health pharmacy located on our main southeast Portland campus (by appointment only). There are also vaccine distribution sites in locations around the state. Visit to find a location near you.

Q: Is the COVID-19 vaccine safe despite its fast development?

A: The COVID-19 vaccines have gone through the same rigorous safety assessment as all vaccines before they are authorized or approved for use in the United States by the FDA. This includes large clinical trials and data review by a safety monitoring board.

Clinical trials of COVID-19 vaccines must first show they are safe and effective before any vaccine can be authorized or approved for use. The known and potential benefits of a COVID-19 vaccine must outweigh the known and potential risks of the vaccine for use under an Emergency Use Authorization.

Even after a vaccine is authorized for approval or use, the FDA and CDC use vaccine safety monitoring systems to ensure the benefits continue to outweigh the risks for people who receive vaccines. According to the CDC:

  • The risk of severe allergic reaction to COVID-19 vaccines in general is two to five per 1 million doses.
  • The risk of blood clots with low platelets following J&J vaccine is less than two per 1 million doses.
  • The risk of death after contracting COVID-19 is 500 to 90,000 out of 1 million people, depending on age/co-morbidities.

Emergency Use Authorization (EUA) does not mean shortcuts were taken in the research or clinical studies to ensure vaccine safety. The COVID-19 vaccines went through the same trials as other vaccines and drugs, just on a different track than is commonly used by the FDA. After hundreds of millions of doses of the vaccine,the FDA and CDC continue to categorize all available brands to be both safe and effective.

Q: Will the shot hurt or make me sick?

A: There may be side effects, but they should go away within a few days. Possible side effects include a sore arm, headache, fever or body aches. This does not mean you have COVID-19. Side effects are signs that the vaccine is working to build immunity. If they don’t go away in a week, or you have more serious symptoms, call your doctor.

Q: Can I get COVID-19 from the vaccine?

A: No. You cannot get COVID-19 from the vaccine. The symptoms you may experience after the shot is due to your body’s immune response — a sign the vaccine is working.

Q: What is a mRNA vaccine?

A: Messenger RNA (mRNA) vaccines are a new type of vaccine to protect against infectious diseases. They teach our cells how to make a protein — or even just a piece of a protein — that triggers an immune response inside our bodies. That immune response, which produces antibodies, is what protects us from getting infected if the real virus enters our bodies.

Here are some other facts about mRNA:

  • mRNA from the vaccine never enters the nucleus of the cell and does not affect or interact with a person’s DNA.
  • Like all vaccines, COVID-19 mRNA vaccines have been rigorously tested for safety before being authorized for use in the United States.
  • mRNA technology is new, but not unknown. It’s been studied for more than a decade.
  • mRNA vaccines do not contain a live or weakened virus. They do not carry a risk of causing disease in the vaccinated person.

Q. What is a vector vaccine?

Like mRNA vaccines, viral vector vaccines teach your cells how to make a protein that triggers an immune response to protect you from the virus. They use a different virus to introduce the instructions to make this protein into your cells. The virus used to do this is harmless and cannot cause disease in humans. Viral vector vaccines have been around since the 1970s, and they have been used in other recent disease outbreaks including Ebola and Zika.

Q: Why is it important to get the COVID-19 vaccine?

A: The health and safety of our patients, visitors, staff and providers are the highest priority for Adventist Health. The COVID-19 pandemic has lasted much longer than we hoped. We continue to do our very best to ensure our communities are protected from COVID-19.

Health care settings in general, and long-term care settings in particular, can be high-risk locations for COVID-19 exposure and transmission. That’s why the Centers for Disease Control and Prevention (CDC) prioritized health care workers as one of the first groups to have access to the vaccine.

Q: How many doses of the vaccine are required?

A: The Johnson & Johnson vaccine requires only one dose. The Pfizer and Moderna COVID-19 vaccines require two doses. Two shots are generally needed to provide the best protection against COVID-19, and the shots are given either 21 or 28 days apart. The first shot primes the immune system, helping it to recognize the virus, and the second shot strengthens the immune response. When you get the Pfizer or Moderna vaccine, it is very important to get the second shot as immunity is not maximized until it is received.

Q: Do both doses of the vaccine have to be from the same manufacturer?

A: The CDC advises that your second dose be the same brand as your first one to ensure completion of the vaccine series with the same product. In the extreme circumstance that the brand used for the first vaccination is not available, it is permissible to substitute the second dose with either vaccine brand and then no other vaccination is needed to complete the series. However, you will need to wait until 28 days have passed since the first dose.

Q: What about a booster?

A: The CDC has strengthened its recommendation on COVID-19 booster shots, telling all adults that they should get an additional dose amid concerns about the newly identified omicron variant. The CDC recently expanded eligibility for COVID-19 boosters to all adults 18 and older as well as to Pfizer recipients 16 and older. Please get your booster shot to protect yourself and your loved ones. Learn more.

Q: Can I take it if I’m pregnant or nursing my baby?

A: COVID-19 vaccines are safe in pregnancy and breastfeeding, and the OB professional societies have recommended vaccines be offered to individuals who are or may become pregnant. However, some individuals in consultation with their obstetrician, pediatrician and/or midwife might prefer to defer their vaccination until after the first trimester of pregnancy.

Q: Can I get the vaccine if I have food or medication allergies?

A: Allergic reactions to the vaccine are possible. Any person with a severe allergy to any part of the vaccine should not receive it. Since many people are not sure which part of a vaccine they are allergic to, CDC recommends caution if you have a severe allergy to any other vaccine or injectable therapy. You may still receive the COVID-19 vaccine if this is the case but may want to discuss with your doctor first. If you have an allergy to foods or other noninjectable drugs, the vaccine is safe to receive.

Q: Can I take the vaccine if I am allergic to eggs?

A: Yes. Eggs or egg-based ingredients are not used at any point in the production of any of the COVID-19 vaccines. They are safe for people with egg allergies.

Q: Can I take the vaccination if I’m allergic to penicillin?

A: Yes. There are no ingredients in the COVID-19 vaccines that should cause issues in patients with penicillin allergies. The CDC recommends patients with severe allergies to any medicine be monitored for 30 minutes after receiving the vaccine as a precaution.

Q: Is the vaccine safe for immunocompromised people?

A: Yes. The vaccine has not been studied in immunocompromised people yet. However, there is no reason to expect it to be less safe in this population than in the general population. The CDC says immunocompromised people may receive the vaccine if they choose. Vaccines are often less effective in immunocompromised patients, so if you are immunocompromised it is especially important to continue following distancing and masking recommendations even after you are vaccinated.

Q: Is physical distancing and masking still necessary if I get vaccinated?

A: Guidelines continue to shift as the pandemic evolves and more and more vaccines are administered. Check the CDC and Oregon Health Authority for the latest information. Also pay attention to signs indicating masks are required at specific stores, restaurants or other locations, and keep an eye on local and county updates too.

Q: If I’ve had COVID already, do I still need the vaccine?

A: Yes. CDC recommends that you get vaccinated even if you have already had COVID-19. If you were treated for COVID-19 with monoclonal antibodies or convalescent plasma, you will have to wait 90 days before getting a COVID-19 vaccine.

Q: Are fetal cells used in the production of COVID-19 vaccines?

A: Actual fetal cells were not used in any way. Cell lines originally derived from fetal tissue were used in various stages of development or production of some COVID-19 vaccines. The cell lines in question came from cells taken from two elective abortions that occurred in the 1970s and 1980s. Since then, the cells have been grown in a lab, and new fetal tissue has not been used at any point since and will not be used going forward.

The cells used today are grown 100% in a laboratory and are thousands of generations removed from the fetal cells from which they were originally derived.

One of these fetal cell lines is used in the production of the Johnson & Johnson vaccine. Fetal cell lines are not used in the production of the Pfizer or Moderna vaccines.

Q: Do the COVID-19 vaccines affect fertility?

A: No. Misinformation circulating on social media claims that antibodies targeting the spike protein of the COVID-19 virus after vaccination or infection also target a protein that is involved in placenta formation called syncytin-1, leading to infertility in women. However, there is no evidence to support this, and these proteins are not actually very similar.

The vaccines do not adversely affect sperm count or quality or otherwise impair male fertility either.

There were pregnancies that occurred in both the vaccine section and placebo section of the clinical trials of the COVID-19 vaccines without any imbalance between the groups. No one who received the vaccine in the trials has had a poor pregnancy outcome to date. In addition, if this claim were true, natural infection with COVID-19 would also lead to infertility since antibodies against the spike protein are produced after an infection as well.

Q: Where can I find more information about the COVID-19 vaccine?

A: Please visit