COVID-19 vaccines: Primary series, additional primary doses, and boosters

  • Where can I get a COVID-19 vaccine?

    There are many places to get vaccinated in your community. Many sites offer booster shots. To find a location near you, visit, or; text your zip code to 438829; or call 1-800-232-0233.  

    Mass General Brigham is offering vaccines at many primary care and some specialty offices alongside visits. You can find out if a COVID-19 vaccine is available at an upcoming visit by contacting your doctor’s office.   

    Mobile van unit near tent

    Mass General Brigham will also continue to distribute vaccines from our mobile community vans. Check the schedule to see if the vans will be near you. Check the schedule to see when the vans will be near you.

    View our mobile van schedule

  • I’m not immunocompromised. Do I need a booster? When should I receive my first booster after my primary vaccine series?

    The CDC recommends that everyone ages 5 years and older should get a booster. When you should get your booster depends on what vaccine you received for the primary vaccine series:

    • For Pfizer and Moderna vaccine: 5 months after receiving the second dose
    • For the Johnson & Johnson vaccine: 2 months after receiving a single dose

    The CDC has a helpful schedule that provides a timeline based on which vaccine you received.

  • What is the difference between an additional primary dose and a booster?

    A booster and an additional primary dose are not the same. An additional primary dose is recommended for people who have compromised immune systems. It is recommended that patients with compromised immune systems receive an additional primary dose to increase their level of protection from the virus. This additional dose completes these patients’ primary vaccine series.

    A booster is an extra dose of vaccine meant to boost a patient’s immune system because of decreased immunity over time.

  • Do I need an additional primary dose?

    People age 5 and older who are moderately to severely immunocompromised should get an additional primary dose. These are people who:

    • Are actively being treated for cancer
    • Have received a solid organ transplant and are taking medicine to suppress the immune system
    • Have received a stem cell transplant within in the last 2 years or are taking medicine to suppress the immune system after a stem cell transplant
    • Have received CAR-T cell therapy
    • Have moderate or severe primary immunodeficiency (including all patients receiving IVIg or SCIg due to an underlying immune deficiency, such as common variable immunodeficiency [CVID]; patients with other underlying immune deficiencies not receiving IgG replacement can be counseled on a case-by-case basis)
    • Have advanced (generally defined as a CD4 count of less than 200 or CD4 percentage of 14 or less) or untreated HIV infection
    • Are taking high-dose corticosteroids (i.e., the equivalent of 20 or more milligrams of Prednisone a day)
    • Are getting other drugs that may suppress the immune response (i.e., tumor-necrosis blockers or other biologic agents that are immunosuppressive or immunomodulatory, including rituximab and ocrelizumab)
  • I am immunocompromised and already got my additional primary dose. When should I receive my first booster after my primary vaccine series?
    • For Pfizer and Moderna vaccine: 3 months after receiving an additional primary dose (i.e., third dose).
    • For the Johnson & Johnson vaccine: 2 months after receiving an additional primary dose of Moderna or Pfizer vaccine.
      • Note: Moderately or severely immunocompromised patients who have already received the first Johnson & Johnson vaccine primary vaccine dose and a booster dose should still receive the additional primary dose of Pfizer or Moderna vaccine at least 2 months after the booster dose.

    The CDC has more information here. The CDC also has a helpful schedule that provides a timeline based on which vaccine you received.

  • Do I need a second booster?

    The Federal Drug Administration (FDA) approved a second booster for certain patients. The CDC recommends the following groups receive a second booster:

    • People ages 18-49 who received Johnson & Johnson’s Janssen COVID-19 vaccine for their first shot and booster
    • Adults ages 50 years and older
    • Patients ages 12 and above who are moderately or severely immunocompromised.

    Note: Patients should receive their second booster at least 4 months after the first booster. The CDC has a helpful schedule that provides a timeline based on which vaccine you received.

  • Should my booster be the same vaccine I received initially, or can I “mix and match”?

    The CDC’s recommendations allow for adults 18 years and older to receive a different booster than their original vaccine. On December 16, 2021 the CDC released new guidance, which notes that mRNA vaccines (i.e., Moderna and Pfizer) are now preferred over Johnson & Johnson vaccine for the booster. However, Johnson & Johnson vaccine may be used in the following situations:

    • When there is a contraindication to mRNA COVID-19 vaccines (e.g., severe allergic reaction after a previous dose or to a component of an mRNA COVID-19 vaccine).
    • When a person would otherwise remain unvaccinated for COVID-19 due to limited access to mRNA COVID-19 vaccines.
    • When a person wants to receive the Janssen COVID-19 vaccine despite the safety concerns identified.

    For children and teens ages 5-17, only Pfizer is approved for both primary vaccination and booster.

  • I’ve already had COVID. Should I wait to get my booster?

    People with active COVID-19 infection should not receive a COVID vaccine dose while in isolation (this includes a booster dose). Individuals must have recovered from illness and be out of required isolation prior to receiving the COVID vaccine.

    There is growing evidence that vaccination following infection increases protection from subsequent infection and hospitalization. People who recently had a COVID infection may consider delaying their first or second booster dose by 3 months from the date symptoms started or the date of positive COVID test (if there were no symptoms). Studies have shown that increased time between infection and vaccination may result in improved immune response to the vaccination. There is also a low risk of reinfection in the weeks to months following infection.

    Individual factors such as risk of severe COVID infection and community levels should be taken into account when determining timing between infection and vaccination and booster administration.

    Read more on the CDC’s website.

  • I heard that the time between the first two primary doses can be extended. Should I wait 8 weeks between my first and second doses of mRNA COVID-19 vaccines (i.e., Moderna and Pfizer vaccines) based on the new CDC guidance?

    The CDC has updated vaccine intervals for people 12 years and older. For non-immunocompromised people 12 years and older, especially males ages 12-39 years, there is more flexibility in timing for the second dose for the Pfizer and Moderna vaccines. An 8-week interval is recommended between first and second doses.

    • Second dose for Pfizer can be given between 3-8 weeks after the first dose
    • Second dose for Moderna can be given between 4-8 weeks after the first dose

    Please note that certain people should continue with the 3-week interval for Pfizer and 4-week interval for Moderna. This includes:

    Remember getting vaccinated is the best way to prevent severe illness from COVID-19. Please make sure everyone in your household is vaccinated and up to date with booster recommendations. This is especially important if you or a family member has conditions that put them at high risk.

  • I misplaced my COVID-19 vaccination card. Can I replace it?

    While we cannot replace the physical CDC vaccination card, patients who were vaccinated at a Mass General Brigham location can receive their immunization history through Patient Gateway. Patients who received their COVID-19 vaccination(s) through a Mass General Brigham provider can now access their vaccination record digitally or via a QR code through Patient Gateway.

    1. Log in to your Patient Gateway account, click on Menu, and select COVID-19 (just under My Record).

      COVID-19 vaccine information will appear if you completed your COVID-19 vaccine series (two doses of Pfizer, two doses of Moderna or one dose of J&J).
    2. From this record, you can take any of these actions:

      Click the down arrow to see vaccine information.

      Click the QR code to open a scannable QR code (if needed at a venue to verify vaccination details).

      Click Download/Export to produce a PDF of the vaccine information that can be printed or saved.
    3. The option to Export to Health Wallet is now available for both iPhone and Android users. Android users who do not see this option will need to upgrade their app to the newest version via Google Play.

    If you are not a current patient registered in Patient Gateway, you can request a hard copy of your vaccination record through Mass General Brigham’s Health Information Management (HIM) Department. You will need to complete an authorization form for release of protected health information. The completed form may be faxed or mailed, and instructions are included in top right corner of the form.

    If you were vaccinated outside of the Mass General Brigham system, you will need request a copy of your vaccination information from the original provider (e.g., CVS, Walgreens).

    The Massachusetts Department of Public Health provides additional guidance on how to replace your card.

What to expect from a COVID-19 vaccine appointment

Read frequently asked questions about what to expect when getting the COVID-19 vaccine, including information about potential side effects.

Frequently Asked Questions about what to expect from vaccination

FAQs about the vaccines

COVID-19 updates: Vaccine safety, prevention, and treatment options

What have we learned about COVID-19 over the past two years? What is the best way to prevent the spread of COVID-19? What are serious symptoms associated with the virus? Erica Shenoy, M.D., Ph.D., FIDSA, FSHEA, Associate Chief, Infection Control Unit, Massachusetts General Hospital, discusses recommendations for the prevention, testing, and treatment of COVID-19.

Where can I find more information?

View more videos from Mass General Brigham

Get up-to-date vaccine information

Vaccine emails from Patient Gateway

Patient Gateway

Patient Gateway is a convenient, secure way to manage your health and communicate with your doctor's office. We are sending regular updates about the COVID-19 vaccine to all enrolled in Patient Gateway.

What is Patient Gateway

Updated June 28, 2022