COVID-19 Vaccine

Frequently Asked Questions

Ver en español

staff unpacking COVID-19 vaccine

Safe and effective vaccines are our best chance of ending the COVID-19 pandemic. Experts from across our health system are preparing for the vaccine and working closely with state officials on planning.

It is important to continue to wash your hands, wear a mask, and socially distance, whether you or someone you know has been vaccinated.

General information  

When can I get the COVID-19 vaccine?

Mass General Brigham is following federal and state guidance from public health officials for vaccine distribution. The first wave of people who are getting the vaccine are frontline health care workers and first responders. Patients in long-term care facilities and nursing homes can also get the vaccine.

Currently, Massachusetts public health officials think the general public will be able to get the vaccine sometime between April and June 2021. Access will be coordinated through the Massachusetts Department of Public Health. If you are high risk, are 65 and older, or work in certain jobs like education, transit, or public works, you might be able to receive the vaccine sooner, between February and April. If you live in another state, please check your state's information.

We are coordinating with the Commonwealth of Massachusetts and expect that we will have more information in the coming weeks on when and how patients can get the vaccine. We will continue to update our website as more information becomes available and encourage you to check here for updates.

The Centers for Disease Control (CDC) has more information on their website about who is high risk for severe illness and about when the vaccine may be available to the general public

If I am 65 years old, can I get the vaccine now that the CDC has changed its guidance?

Recently, the federal government announced that states may choose to offer the vaccine to those age 65 years and older. The state of Massachusetts is currently planning to offer vaccine to those age 75 years and over beginning in February. We are aware that Massachusetts is evaluating the federal government’s recent announcement, but it is currently unknown if Massachusetts will change the age criteria in their vaccination priorities. If Massachusetts does make any changes to its current plans, we will follow the state guidance and will notify patients of any changes through Patient Gateway and on our website (

Can children get the vaccine?

Currently, the Pfizer vaccine is approved for youth ages 16 and older. The Moderna vaccine is approved for individuals 18 years of age and older. The trials of each of these vaccines was limited to these age ranges and did not include younger individuals. 

How do we know the vaccine works?

The COVID-19 vaccine has proven to be extremely effective. According to Phase 3 trials, the Pfizer vaccine is 95% effective 7 days after the second dose. The Moderna vaccine is 94% effective 14 days after the second dose. These results were consistent across gender, age, race, and ethnicity.

How long will immunity last after I get vaccinated? Will I need to be vaccinated every year?

We do not know this yet. The clinical trials will continue to monitor participants to see how long protection lasts. We will provide updated information as it becomes available.

Because we don’t yet know how long immunity will last, it’s still important to wash your hands, wear a mask, and socially distance.

Can we stop wearing masks and social distancing after getting vaccinated?

No, not yet. We know that the vaccine protects you from getting sick, but we do not know if it stops you from giving it to other people. Since not everyone will get the vaccine right away, we must be careful to protect others. Even if you get the vaccine, you should still wear a mask, practice social distancing, and wash your hands. Infection control experts will let us know when it is safe to modify or stop these safety measures.

Why do we need to get the vaccine if we’re wearing masks and social distancing? 

We need to use all the tools available to us to stop the pandemic. Together, the COVID-19 vaccine and simple everyday actions like wearing a mask and social distancing will offer the best protection from COVID-19. And even though the vaccines are 90% to 95% effective, you still don’t know how effective it will be for you. About 5% to 10% of people immunized may still get the virus. You should do everything you can to reduce your risk of getting the virus and passing it to others. 

Can people get COVID-19 from a vaccine?

No. The vaccine does not contain the whole or live virus and therefore cannot cause COVID-19.

I already had COVID-19. Should I get vaccinated?

Yes, when it becomes available to you, you can still get the vaccine if you have had COVID-19 and have recovered. If you are actively sick with COVID-19 or have symptoms that could be from COVID-19, you should not get the vaccine. 

Can I get a COVID-19 vaccine with other vaccines?

When possible, you should avoid getting other vaccines for 14 days before or after you get the COVID-19 vaccine. If you get a COVID-19 vaccine within 14 days of another vaccine, you do not have to get it again. 

What are the side effects of the vaccine?

Some people do get side effects after receiving the vaccine. For both the Pfizer and Moderna vaccines, most mild side effects resolve within a day or so.

  • The most commonly reported symptoms from the Pfizer vaccine have been pain at the site of vaccination, fatigue, headache, muscle pain, joint pain, and chills. 
  • The most commonly reported symptoms from the Moderna vaccine have been pain at the injection site, tiredness, headache, muscle pain, chills, joint pain, swollen lymph nodes in the same arm as the injection, nausea and vomiting, and fever.

Where can I find more information?


  • Should I be concerned about allergic reactions to the COVID-19 vaccine? 

    There have been some reports of people having allergic reactions after getting the vaccine. A small number of people had a severe allergic reaction called anaphylaxis. Based on this, the U.S. Food and Drug Administration and the CDC recommends that people with a history of anaphylaxis to any of the ingredients in the COVID-19 vaccine should not get the vaccine. People with other food or medication allergies can receive the vaccine.

    In general, most patients allergic to one vaccine can receive other vaccinations safely. If you have a history of severe allergic reactions to vaccines, injectable therapies, or any component of the COVID-19 vaccine you are going to receive, you should talk to your primary care provider or allergist (if you have one). Your provider can help you decide if it is safe to get vaccinated.  

  • What are the ingredients in the Pfizer-BioNTech and Moderna COVID-19 vaccines? 

    The Pfizer and Moderna COVID-19 vaccines do not contain gelatin, egg, or latex. Also, the vial stoppers are not made with natural rubber latex. Patients who have latex allergies can receive the Pfizer or Moderna COVID-19 vaccines. 

    Both the Pfizer and Moderna COVID-19 vaccines contain polyethylene glycol. Reactions to polyethylene glycol are very rare. Patients with a history of having an allergic reaction to polyethylene glycol should talk to their provider before receiving either the Pfizer or Moderna vaccine. 

      Pfzier-BioNTech Moderna
    Active Nucleoside-modified messenger RNA (modRNA) encoding the viral spike (S) glycoprotein of SARS-CoV-2. Nucleoside-modified mRNA encoding the viral spike (S) glycoprotein of SARS-CoV-2
    Inactive - lipids
    • (4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)
    • 2[(polyethylene glycol [PEG])-2000]-N,N-ditetradecylacetamide
    • 1,2-distearoyl-sn-glycero-3-phosphocholine
    • Cholesterol
    • SM-102 (Proprietary to Moderna) 
    • Polyethylene glycol (PEG) 2000 dimyristoyl glycerol (DMG)
    • 1,2-distearoyl-sn-glycero-3-phosphocholine
    • Cholesterol 
    Inactive – salts, sugars, buffers 
    • Potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dihydrate
    • Sugar (sucrose)
    • The diluent, added to the vaccine for administration, is saline (Sodium Chloride)
    • Tromethamine, tromethamine hydrochloride, acetic acid, sodium acetate
    • Sugar (sucrose)
    • No diluent needed

Immunocompromised patients

  • I am immunocompromised. Should I get the COVID-19 vaccine?

    The CDC has stated that people who are immunocompromised may receive the COVID-19 vaccines, as long as they have had no issues with getting vaccines in the past. For questions about allergies and the vaccines, please see the allergy frequently asked questions.

    Please note, the COVID19 vaccines are not live vaccines; live vaccines are often not recommended for immunocompromised patients.

    Patients who are immunocompromised include:

    • Living with HIV
    • On immunosuppressive therapies like steroids (prednisone) for a long time
    • On immunosuppressive therapies for prevention of organ transplant rejection
    • On immune altering medications like biologic therapies (often injectable). These are used for treatment of autoimmune diseases such as Crohn’s disease, rheumatoid arthritis, lupus, and others.

    It is not known how effective the COVID-19 vaccines will be for you. You may have less of an immune response to the vaccine. Even if you get the vaccine, you should still wear a mask, practice social distancing, and wash your hands. This is true for everyone getting vaccine now. Infection control experts will let us know when it is safe to modify or stop these safety measures. For now, we do not know if you may need long-term boosters or revaccination. We may not be doing repeat vaccination until everyone is vaccinated.

  • Should my immunosuppression medications be altered when I get the vaccine?

    In general, we are not recommending altering the immunosuppression before or after vaccination. In specific cases, your provider may recommend changes. If you have questions, consider discussing this during your next medical visit.

  • Can I get the COVID-19 vaccine if I have had an organ transplant?

    You can get the vaccine. It’s possible that the vaccine may be less effective in providing protection for you. It may be best to wait to get vaccinated at least 3 months after your transplant if possible, in order to improve the immune response to the vaccine (when your immune suppression may be less). There is no preference for the Pfizer-BioNTech or Moderna vaccines. Your transplant provider will tell you if you need transplant labs after vaccination.

  • I am waiting for organ transplantation. Should I get the vaccine?

    In general, vaccines work better before organ transplant, before the immunosuppression is started. If possible we would recommend that you get the vaccine before transplant. We do not currently have mechanisms now to expedite that.

Pregnancy and breastfeeding

  • I am pregnant. Should I get the COVID-19 vaccine?

    Vaccination, especially with vaccines that do not contain live virus, are considered a safe and routine part of prenatal care. For example, the flu shot is not only offered during pregnancy but recommended.  

    In line with recommendations from the CDC, when the COVID-19 vaccine is available for patients, it will be offered to those who are pregnant. However, you should speak with your OB/GYN about whether or not you should get vaccinated. Both the virus and the vaccine are new. There is very little data on the safety of this vaccine in pregnancy as pregnant people were not included in the trials of the vaccines. However, 18 individuals who received the vaccine in the studies did become pregnant after vaccination. So far those pregnancies are ongoing. We hope to learn more about those individuals soon. Like many new medications and vaccines, the COVID-19 vaccine was studied in pregnant animals and these studies did not show any complications related to the vaccine.

    With the help of your OB/GYN, you can discuss what is the best option for you. This will be based on your risk for exposure to the virus and how sick you might get if you do get the virus.

  • If I decide to get the vaccine during pregnancy does it matter when I get vaccinated?

    The decision about when you get vaccinated should be made together with your OB/GYN. This should consider your risk of exposure to the virus and what your chance of getting very sick might be if you do get the virus. There is no data to suggest that the COVID-19 vaccines cause miscarriage.

  • I heard that some people had reactions after vaccination. Are these dangerous in pregnancy?

    Symptoms including fever, muscle aches, joint pains, fatigue, and headache are common side effects of the vaccine (particularly after the second dose). Most mild side effects resolve within a day or two and are not believed to be dangerous. If you are worried about side effects from the vaccine and your pregnancy, talk to your OB/GYN before getting the vaccine.

  • I am breastfeeding. Should I get the vaccine?

    When the vaccine is available for patients, it will be offered to breastfeeding individuals. At this time, there is no data regarding the safety of this new vaccine on breastfed infants of mothers who were vaccinated. However, any vaccine that makes it into the breast milk is likely to be quickly inactivated when the milk is digested. In addition, some of your COVID-19 immunity can pass to the baby through the breastmilk after you receive the vaccine.

  • Will the vaccine affect my chance of getting pregnant in the future?

    There is no evidence that vaccines affect future fertility.

  • What if I become pregnant between the first dose of the vaccine and the second shot?

    You can choose to either get the second dose during pregnancy or wait to get the second dose until after you have had your baby. Many individuals who have already had the first dose may choose to get the second dose so they will become immune during pregnancy.

  • I am planning pregnancy in the near future. Should I get vaccinated now or wait?

    The COVID-19 vaccines are not believed to affect your future fertility. Getting vaccinated before you get pregnant may prevent COVID-19 during pregnancy. It can also avoid the need for vaccination during pregnancy. However, whether or not you wait to get vaccinated may depend on when the vaccine is available to you.

FAQ information updated 1/15/21

Video series about our vaccine planning

Experts at Mass General Brigham have been planning with state officials. We continue to prepare to ensure the vaccine is safely and effectively administered to our workforce and patients.

How we prepared for the vaccine

Rochelle Walensky, M.D. M.P.H., Chief of the Division of Infectious Diseases at Massachusetts General Hospital, and Daniel Kuritzkes, M.D., Chief of the Division of Infectious Diseases at Brigham & Women's Hospital, discuss how our health system is preparing to for a COVID-19 vaccine.

Ensuring equity

We are committed to equity in vaccinating all the communities that we serve.

Vice President and Chief Equity and Inclusion Officer at Massachusetts General Hospital, Joseph Betancourt, M.D., and Vice President of Community Health and Health Equity at Brigham and Women's Hospital, Wanda McClain, discuss how the health system is ensuring equitable distribution of the COVID-19 vaccine.

Vice President and Chief Equity and Inclusion Officer at Massachusetts General Hospital, Joseph Betancourt, M.D., and Vice President of Community Health and Health Equity at Brigham and Women's Hospital, Wanda McClain, discuss how the health system is building trust for the COVID-19 vaccine.

View more videos from Mass General Brigham

You may also be interested in

Hello and welcome to
Mass General Brigham

This is the website for Mass General Brigham, formerly known as Partners HealthCare. We're emerging with a more recognizable name and a strong intention: to connect more closely with our patients and communities.