COVID-19 vaccine frequently asked questions for patients
Should I get vaccinated for COVID-19?
What vaccines are available?
What is a messenger RNA vaccine?
What is a vector vaccine?
Why do I need two COVID-19 shots?
Will the shot hurt or make me sick?
Can I get COVID-19 from the vaccine?
Is the COVID-19 vaccine safe?
If I already had COVID-19 and recovered, do I still need to get vaccinated?
What if I am outside the time period for my second dose?
If I had one brand for my first dose, can I choose a different brand for
my second dose?
What about a booster?
Can my child get vaccinated for COVID-19?
Do the COVID-19 vaccines affect fertility?
Can I take it if I’m pregnant or nursing my baby?
Can I get the vaccine if I have food or medication allergies?
Can I take the vaccine if I am allergic to eggs?
Can I take the vaccination if I’m allergic to penicillin?
Is the vaccine safe for people with compromised immune systems?
Do I need to wear a mask when I receive the COVID-19 vaccine?
Are fetal cells used in the production of COVID-19 vaccines?
Where can I find more information about the COVID-19 vaccine?
Should I get vaccinated for COVID-19?
CDC now recommends COVID-19 vaccines for everyone 6 months and older and boosters for everyone 5 years and older, if eligible. For more information regarding COVID-19 vaccines for children and teens, please see the CDC recommendations.
In addition, two boosters are now recommended for adults 50 years and older, and some people 12 years and older. For more information regarding COVID-19 booster eligibility, please see the CDC's eligibility table.
What vaccines are available?
There are four approved or authorized vaccines in the United States used to prevent COVID-19. Pfizer-BioNTech and Moderna are COVID-19 mRNA vaccines. You can also get the Novavax COVID-19 protein subunit vaccine. Otherwise, you may get Johnson & Johnson’s Janssen (J&J/Janssen) COVID-19 viral vector vaccine in some situations.
What is a messenger RNA vaccine?
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.
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 in order 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 virus.
Why do I need two COVID-19 shots?
Currently authorized vaccines, and most vaccines under development, require two doses. The first shot helps the immune system recognize the virus, and the second shot strengthens the immune response. You need both to get the best protection. The Johnson & Johnson vaccine only requires one dose.
Will the shot hurt or make me sick?
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.
Can I get COVID-19 from the vaccine?
No. It is not possible to get COVID-19 from the vaccines as none of them contains the live virus.
Is the COVID-19 vaccine safe?
COVID-19 vaccines go through the same rigorous safety assessment as all vaccines before the FDA approves them for use in the United States. This includes large clinical trials and data review by a safety monitoring board. The U.S. Food and Drug Administration (FDA) has fully approved Moderna’s COVID-19 vaccine for those 18 and older. Now, both the Pfizer and Moderna two-dose vaccines have full FDA approval and meet the FDA’s rigorous standards for safety, effectiveness and manufacturing quality requirements.
If I already had COVID-19 and recovered, do I still need to get vaccinated?
Yes. CDC recommends that you get vaccinated even if you have already had COVID-19, and the CDPH order requires vaccination. 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.
What if I am outside the time period for my second dose?
Although it is preferable that you get your second dose within the time period suggested by the manufacturer, you can still receive your second dose months later and still be considered fully vaccinated.
If I had one brand for my first dose, can I choose a different brand for my second dose?
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.
What about a booster?
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 for everyone 5 years and older, if eligible. Please get your booster shot to protect yourself and your loved ones. Learn more.
Can my child get vaccinated for COVID-19?
CDC now recommends COVID-19 vaccines for everyone 6 months and older and boosters for everyone 5 years and older, if eligible. Learn more.
Do the COVID-19 vaccines affect fertility?
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.
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, and 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.
Can I take it if I’m pregnant or nursing my baby?
COVID-19 vaccines are safe in pregnancy and breastfeeding, and the OB professional societies have recommended that 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.
Can I get the vaccine if I have food or medication allergies?
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 non-injectable drugs, the vaccine is safe to receive.
Can I take the vaccine if I am allergic to eggs?
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.
Can I take the vaccination if I’m allergic to penicillin?
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.
Is the vaccine safe for people with compromised immune systems?
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 recommends that immunocompromised people receive the vaccine if they choose. Because vaccines are often less effective in immunocompromised patients, it is especially important for those who are immunocompromised to continue following distancing and masking recommendations even after they are vaccinated.
Do I need to wear a mask when I receive the COVID-19 vaccine?
Yes. CDC recommends that during the pandemic people wear a mask that covers their nose and mouth when in contact with others outside your household, when in healthcare facilities and when receiving any vaccine, including a COVID-19 vaccine. Anyone who has trouble breathing or is unable to remove a mask without assistance should not wear a mask.
Are fetal cells used in the production of COVID-19 vaccines?
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.
Where can I find more information about the COVID-19 vaccine?
Please visit cdc.gov/coronavirus.