Below are some frequently asked questions about the COVID-19 vaccine.
The following Frequently Asked Questions were developed based on information from the U.S. Centers for Disease Control and the Virginia Department of Health. Go to the Resources section of this page for links to the relevant sources.
General Vaccine FAQs
Question: When can I get the vaccine?
Answer: As long as you are 5 years or older, you are eligible to receive the COVID-19 vaccine. Visit vaccines.gov to find a vaccine appointment near you.
Question: How do the vaccines work?
Answer: The Pfizer® and Moderna® vaccines use mRNA, a blueprint for proteins, to use our own cells to create a protein that resembles the spike protein of the virus itself. Our body’s immune system then responds to that protein to develop protective antibodies. This technology has been studied since 2005, and its use was accelerated, without removing any of the steps to determine safety and effectiveness, to respond to the current pandemic.
The Janssen/Johnson & Johnson® vaccine uses adenovirus 26 (Ad26) viral vector technology to deliver a blueprint for our own cells to make a protein that resembles portions of the spike protein of SARS-CoV2. Our body’s own immune system then responds to that protein to develop protective antibodies. This same Ad26 delivery system has been used to create vaccines for other viral diseases.
Question: Do the vaccines contain live virus?
Answer: No, none of the vaccines contain live virus.
Question: Will I need multiple shots?
Answer: There are currently three vaccines available on the market, all of which have different schedules.
- The Pfizer® vaccine is two doses, separated by 17 to 21 days. Even if you miss this timeframe, it is important that you get the second dose of vaccine as soon as you can.
- The Moderna® vaccine is two doses, separated by 28 days. Even if you miss this timeframe, it is important that you get the second dose of vaccine as soon as you can.
- The Janssen/Johnson & Johnson® vaccine is given as a single-dose intramuscular (IM) injection.
Question: For Pfizer® and Moderna®, if I'm not able to get the second dose when required, will I have to take the first dose again?
Answer: No, it is not recommended to restart the series. Get the second dose as soon as possible to finish the vaccination series.
Question: Will I need a booster dose?
Answer: Yes, the CDC is currently recommending boosters for anyone who had their last dose of the Pfizer® or Moderna® vaccines more than 6 months ago or anyone who had their last dose of the Janssen/Johnson & Johnson® vaccine more than 2 months ago.
Question: Do I need to get the same vaccine brand for my booster that I received for my initial dose(s)?
Answer: No, you can choose to get any brand as a booster; however, we recommend boosting with mRNA vaccine (Pfizer® or Moderna®) due to the increased antibody response.
Question: When is a third dose needed and how do I know if I qualify?
Answer: For the mRNA vaccines, there is data for patients with significant immunosuppression that showed their ability to mount a response and protection against getting a serious COVID-19 infection was reduced. Additional studies also showed that a third dose at least 28 days after the 2nd dose had a significant increase in immunity for these patients.
If you think you qualify for a third dose, you should talk to your health care provider about your medical condition and whether getting an additional dose is appropriate for you.
Question: How well does the vaccine work?
Answer: The three vaccines are all highly effective at preventing severe disease, hospitalization and death from COVID-19. They were tested at different times during the pandemic, using slightly different outcome measures, and never “head to head,” so the exact percentages of various kinds of protection between the three vaccines should not be directly compared.
Question: How long does it take for the vaccine to work?
Answer: The CDC considers people to be fully vaccinated two weeks after the second dose of the Pfizer® and Moderna® vaccines, and two weeks after the single Janssen/Johnson & Johnson® vaccine.
Question: Is the vaccine safe?
Answer: It is completely understandable that there may be concerns about safety for a vaccine that was developed so quickly. These vaccines appear to be very safe. This is based on several facts:
- The FDA has required all vaccine developers to adhere to the same set of safety steps and stages in development to help ensure safe products; these have occurred in an accelerated fashion to allow approval of the vaccine during the pandemic.
- Surveillance for safety concerns will be conducted aggressively at every site administering vaccines.
- Current trials involving over 110,000 participants indicate that the vaccine is safe, with no significant adverse events other than the mild to moderate side effects discussed below.
Question: Is it safe for the elderly? What about pregnant or lactating women?
Answer: Elderly patients, with and without other illnesses such as diabetes, high blood pressure, and being overweight, were included in the clinical trials and the vaccine was demonstrated safe and effective in these patients.
Pregnant or lactating women were not included in the initial trails, but they may elect to receive the vaccine since the risk of severe COVID‑19 is increased in pregnant women which may have unwanted effects on the fetus. Many pregnant and lactating women have received the vaccines without adverse effects. While mRNA vaccines have not been used widely in pregnancy, they do not contain live virus. Patients who are pregnant or lactating and are in a group currently prioritized to get the vaccine should weigh the risks and benefits with their health care provider.
Question: Are there side effects?
Answer: According to the clinical trial data, the Pfizer®, Moderna®, and Janssen/Johnson & Johnson® COVID-19 vaccines are associated with some side effects. Some people who receive this vaccine may experience mild to moderate side effects that may include fever, headache, muscle and joint aches as happens with many other vaccines; for the Pfizer® and Moderna® vaccines, this happens more often after the second shot than the first. Most will not experience these side effects; for those that do, they generally start about 10 hours after vaccination and are gone within 24-48 hours after vaccination.
The Janssen/Johnson & Johnson vaccine has been associated with very rare cases of cerebral venous sinus thrombosis (CVST) along with low platelets (6 cases out of approximately 7 million doses delivered as of 4/23/2021). Blood clots at other sites (abdomen and leg) have also been described rarely. These occurrences are called TTS, or thrombosis-thrombocytopenia syndrome. They are treated with blood thinners other than heparin. Most of these events have occurred in females aged 18-49 years 1-2 weeks after vaccination; some have been fatal. More information about the J&J vaccine and its side effects can be found on the patient fact sheet.
Question: Should I get the vaccine if I’ve had COVID-19 already?
Answer: Yes. Patients with previous COVID-19 infection were given the vaccine in the trial. Although small numbers, there were some data to suggest that the vaccine provided additional immunity. Re-infection is very uncommon and has not been described within 90 days of COVID-19 infection; therefore, for persons with documented acute infection in the preceding 90 days; while we suggest immediate vaccination after self-isolation has ended, some may choose to defer vaccination until after 90 days have passed.
Question: Can I get the flu vaccine at the same time as the COVID-19 vaccine?
Answer: The Virginia Department of Health recommends that the COVID-19 vaccine series be administered at least two weeks before or after any other vaccine to ensure the safety and efficacy of each vaccine. You should reschedule your COVID-19 vaccination appointment if you receive the flu vaccine, a tetanus shot or any other vaccine within two weeks of the date.
Question: What are the contraindications?
Answer: The vaccines are contraindicated for a) anyone who has had a severe allergic reaction (e.g., anaphylaxis) after a previous dose or to a component of the vaccine (the main components of concern are polyethylene glycol (PEG) and polysorbate); and b) for anyone with an immediate allergic reaction of any severity after a previous dose or known (diagnosed) allergy to a component of the vaccine—this includes any hypersensitivity-related signs or symptoms consistent with urticaria (hives), angioedema (swelling of the body), respiratory distress (e.g., wheezing, stridor [gasping]) or anaphylaxis that occur within four hours following administration.
The vaccine is not indicated in anyone less than 5 years of age for the Pfizer® vaccine and less than 18 years of age for the Moderna® and Janssen/Johnson & Johnson® vaccines.
Anyone with a severe allergy to other vaccines or any injectable medication (intravenous or other delivery route) should discuss with their physicians whether to receive the vaccination; if the decision is to receive the vaccination, then the person should be observed for 30 minutes after receiving the injection in a setting in which severe reactions can be treated.
Anyone who received convalescent plasma or a monoclonal antibody intended to treat COVID-19 should wait 90 days before getting the vaccine.
More information on the COVID-19 and its contraindications can be found on the CDC website.
Question: If I get the vaccine, do I still need to wear a mask?
Answer: In some instances, yes. While the vaccine will protect you from getting ill, there are several reasons you need to keep wearing masks, practicing social distancing, washing hands and avoiding large gatherings until many others across the country get the vaccine. Transmission to and from others is still being formally studied as we work to combat this virus in the community.