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COVID-19 Vaccine FAQ

Visitor Guidance | Keeping You Safe | COVID-19 Vaccine |

COVID-19 Booster Shot FAQ

Who can get a booster shot?

Booster dose is available to qualified individuals ages 12 and older including:

  • Individuals who have already received both doses of the Pfizer or Moderna vaccine, or one dose of the J&J vaccine with the last dose received at least two months ago.
  • Individuals who received a Pfizer or Moderna booster dose, at least two months ago.

To see who can get a booster shot, click here.

Why do I need a booster?

Recent data suggest COVID-19 vaccine effectiveness at preventing infection or severe illness wanes over time, especially for certain groups of people, such as people ages 65 years and older and people with immunocompromise.

The emergence of COVID-19 variants further emphasizes the importance of vaccination, boosters, and prevention efforts needed to protect against COVID-19.

Data show that an mRNA booster increases the immune response, which improves protection against getting a serious COVID-19 infection.

What is the bivalent booster?

The updated (bivalent) boosters are called “bivalent” because they protect against both the original virus that causes COVID-19 and the Omicron variant BA.4 and BA.5.

Previous boosters are called “monovalent” because they were designed to protect against the original virus that causes COVID-19. They also provide some protection against Omicron, but not as much as the updated (bivalent) boosters.

The virus that causes COVID-19 has changed over time. The different versions of the virus that have developed over time are called variants. Learn more about variants of the COVID-19 virus.

Two COVID-19 vaccine manufacturers, Pfizer and Moderna, have developed updated (bivalent) COVID-19 boosters.

What booster can I get?

To see who can get a booster shot, click here.

If we need a booster shot, are the vaccines working?

Yes. COVID-19 vaccines are working well to prevent severe illness, hospitalization, and death among people who are fully vaccinated. However, public health experts are seeing reduced protection over time against mild and moderate disease, especially among certain populations.

Am I still considered "fully vaccinated" if I don't get a booster shot?

Yes, the definition of fully vaccinated does not include a booster. Everyone, except those who are moderately or severely immunocompromised, is still considered fully vaccinated two weeks after their second dose in a two-dose series, such as the Pfizer-BioNTech and Moderna vaccines, or two weeks after the single-dose J&J/Janssen vaccine. Fully vaccinated, however, is not the same as having the best protection. People are best protected when they stay up to date with COVID-19 vaccinations, which includes getting boosters when eligible.

General COVID-19 Vaccine FAQ

(For the most recent updates on the COVID-19 vaccines, please visit

How was the COVID-19 vaccine developed and tested?

  • Approval of a vaccine for use in people involves multiple phases with different goals for assessing effectiveness and safety in different populations. There are four distinct phases, and the vaccine must meet very intense safety criteria before completing each phase. Once a vaccine is approved for use after phase 3, it has been tested in tens of thousands of people and if no significant harmful side effects are noted, it is considered safe for use. Phase 4 involves continued monitoring and gathering of safety data. This type of clinical trial has been used for decades to approve medications and vaccines.

What are the Food and Drug Administration (FDA) requirements for the safety and efficacy of a COVID-19 vaccine?

  • FDA requires 50% efficacy of a COVID-19 vaccine (the COVID-19 vaccines from Pfizer and Moderna are showing 94-95% efficacy in preventing COVID-19 disease during this trial phase). Many other companies are working on a vaccine and we expect that others will be approved by the FDA.
  • FDA requires 8 weeks (about 2 months) of safety data on the COVID-19 vaccine

What is an Emergency Use Authorization (EUA) and if the vaccine is approved for an EUA, what does that mean?

  • An EUA is based on the need to use a vaccine quickly to save lives during an urgent health crisis.
  • You may be anxious about the speed with which a vaccine has been approved. While the EUA is a shorter process, no steps are skipped in the safety evaluation process.
  • This approval can still take weeks and the U.S. Food and Drug Administration (FDA) will re-evaluate the numbers and data to ensure that the calculations are correct.
  • The FDA has reviewed and evaluated the vaccine’s risks and benefits as they would with all vaccines.
  • The FDA formally granted emergency approval for Pfizer-BioNTech’s coronavirus vaccine candidate on Friday, December 11, 2020.

How do we know the vaccine is safe?

  • COVID-19 vaccines have been rigorously evaluated for safety and effectiveness.
  • We follow the scientific evidence and have confidence in the three COVID-19 vaccines developed
    by Pfizer, Moderna, and Johnson & Johnson. They all have met the rigorous FDA safety and efficacy
    standards and are proven to be extremely effective in preventing COVID-19 and most importantly in
    preventing serious harm including death from the infection. The Pfizer vaccine has the U.S. Food and
    Drug Administration’s full approval in individuals 16 years of age and older and continues to be available
    under emergency use authorization for people 5-15 years of age. The Moderna and Johnson & Johnson
    vaccines also continue to be available under emergency use authorization for individuals 18 years of age
    and older. Nearly 400 million doses have been safely administered in the U.S. and billions of doses have
    been administered worldwide -- and we are seeing in real time that they work.

Who evaluates vaccines to ensure they are safe and effective?

  • There are two advisory committees: (1) The Vaccine and Related Biological Products Advisory Committee (VRBPAC) that advises the FDA 2020 Meeting Materials, Vaccines and Related Biological Products Advisory Committee | FDA; (2) The Advisory Committee on Immunization Practices (ACIP) that advises the CDC Advisory Committee on Immunization Practices (ACIP) | CDC
  • These advisory boards are independent from the FDA. Their job is to monitor vaccines to ensure safety regardless of money, politics, etc.
  • The people on these committees are experts from academic institutions and they are vetted to avoid a conflict of interest. Experts who may have a conflict of interest are not put on these committees.
  • The committees have evaluated the vaccine data for safety and efficacy and help to determine how it will be distributed.

How does an mRNA vaccine work?

  • The vaccine is administered into our arm muscle (intramuscular injection) which gives our cells a message by using what is called a “spike protein.” This protein cannot build a virus or cause infection, it gives our cells instructions on how to make a harmless protein that is unique to the virus. After our cells make copies of the protein, they break it down and get rid of it. Our bodies recognize that the protein should not be there, and it builds antibodies that will remember how to fight the virus that causes COVID-19 if we are infected in the future.
  • While mRNA technology is new in vaccine development, this technology is being successfully used in cancer treatments.
  • For more information, visit the CDC website:

How much does the vaccine cost?

  • Currently, vaccine doses have been purchased by the federal government for immediate use and are given to the American people at no cost.

How does the vaccine help with the spread of COVID-19?

  • Getting vaccinated is one of many steps you can take to protect yourself and others from COVID-19. Protection from COVID-19 is critically important because for some people, it can cause severe illness or death.
  • Stopping a pandemic requires using all the tools available. Vaccines work with your immune system so your body will be ready to fight the virus if you are exposed. Other steps, like masks and physical distancing, help reduce your chance of being exposed to the virus or spreading it to others. Together, COVID-19 vaccination and following the CDC’s recommendations to protect yourself and others will offer the best protection from COVID-19.

When will we be protected after we get the vaccine?

  • Most COVID-19 vaccines require 2 shots, within 21-28 days (about 4 weeks) between each shot, and protection will usually occur about 2 weeks after the second shot.
  • Protection is not immediate and current practices such as wearing a mask, physical distancing and practicing frequent hand hygiene will need to be continued.

What if I had COVID-19 or took a test that showed I have antibodies? Should I get the vaccine?

  • Due to the severe health risks associated with COVID-19 and the fact that reinfection with COVID-19 is
    possible, you should get vaccinated regardless of whether you already had COVID-19 or not.

What are some of the possible side effects of the COVID-19 vaccine? Will the vaccine make me sick?

  • Like most vaccines, the COVID-19 vaccine can produce generally mild and temporary side effects. Some people who’ve received the COVID-19 vaccine have reported fevers, fatigue, muscle aches, and soreness around the injection site. These side effects are normal and a sign that the body is building immunity.
  • If you experience discomfort after the first dose of the vaccine, it is especially important that you still receive the second dose a few weeks later for the vaccine to be effective.
  • This does not mean that the vaccine has given you COVID-19. The vaccines do not contain the live COVID-19 virus and cannot give you COVID-19. They take advantage of the body’s natural immune response to generate protection.
  • In some cases, a person may already be infected with COVID-19 when they get the vaccine but are asymptomatic or pre-symptomatic. If they later have symptoms of COVID-19 or test positive for it, it does not mean they got COVID-19 from the vaccine.

If I have symptoms of COVID-19 after receiving the vaccine, should I call out sick?

It will be important to understand the difference between side effects and symptoms consistent with COVID-19.

Common side effects include:

  • Pain or tenderness at the injection site, fatigue, headache, general aches

These may last a few days. We recommend taking the vaccine when you are scheduled to be off the next day, please plan accordingly.

Symptoms consistent with a COVID-19 Infection Include:

  • Fever, chills, cough, shortness of breath, fatigue/tiredness, muscle pain, sore throat, headache, runny nose, diarrhea, nausea/vomiting, loss of sense of taste, loss of sense of smell

If you develop a high fever or you develop symptoms consistent with COVID-19 that seem to get worse or if you have concerns, please stay home and call your employer to discuss next steps.

What if I’m pregnant or plan to become pregnant, is the vaccine safe?

The COVID-19 vaccine is recommended for people who are pregnant, breastfeeding, or planning to become pregnant.

The CDC recommends COVID-19 vaccination for people who are pregnant or planning to become pregnant. Experts believe that, based on how each of these vaccines works in the body, none of the authorized or approved vaccines are likely to pose a specific risk for people who are pregnant.

There are several benefits of vaccination for people who are pregnant or considering
becoming pregnant:

  • Being pregnant increases the risk of getting COVID-19.
  • Being pregnant may also increase the risk of severe COVID-19 infection, especially among Latina
    and African American people.
  • Pregnant people with COVID-19 are at increased risk of maternal and fetal complications such as
    preterm labor.
  • Getting vaccinated during pregnancy can protect your baby as well as you.

If you are pregnant or planning to become pregnant, please discuss risks and benefits as well as questions or concerns with your OBGYN prior to deciding whether to get the vaccine.

What if I’ve had allergies to certain foods, medications, or other vaccines – is the vaccine safe?

  • You should not get the second dose of the Pfizer-BioNtech COVID-19 Vaccine if you had a severe allergic reaction after your first dose of this vaccine, or had a severe allergic reaction to any ingredient of this vaccine. If you have severe allergic reactions to certain foods or medications, please consult with your Primary Care Provider to determine if this vaccine is recommended for you. For additional information about the Pfizer-BioNTech vaccine, click here.

What are the ingredients in the Pfizer-BioNtech COVID-19 Vaccine?

  • The Pfizer-BioNTech COVID-19 Vaccine includes the following ingredients: mRNA, lipids ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate), 2 [(polyethylene glycol)-2000]-N,N-ditetradecylacetamide, 1,2-Distearoyl-sn-glycero-3- phosphocholine, and cholesterol), potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dihydrate, and sucrose. For additional information about the Pfizer-BioNTech vaccine, click here.

Where can I find more information about the vaccine?

  • Ask your family medical provider about the vaccine and have them share information and answer questions. You can talk to them about how they are planning to make their decision to get the COVID-19 vaccine.
  • It is important to get your information from reliable sources, such as the CDC (, the Immunization Action Coalition (, and other providers so you can get accurate information.
  • Social media is full of misinformation and opinions based on that misinformation, so be careful to look to reputable sources (such as those affiliated with academic institutions or non-profit professional organizations like AMDA (American Medical Directors Association)) . For information, visit the link below:

If you have any further questions that you do not see in the FAQs, please submit them here.