In February 2021, the FDA approved Emergency Use Authorization (EUA) for the Johnson & Johnson single-dose COVID-19 vaccine which followed the approval in December 2020 for the Pfizer/BioNTech and Moderna COVID-19 vaccines, all of which are beginning to be distributed across the country. Mark Poznansky, MD, PhD, director of the Vaccine & Immunotherapy Center at Massachusetts General Hospital offers guidance and answers to common questions regarding this latest development in the fight against COVID-19.

For the latest information on the COVID-19 vaccine, click here

Are there any COVID-19 vaccines approved by the Food and Drug Administration (FDA)?

Currently, the FDA has given Emergency Use Authorization for the Johnson & Johnson, Pfizer/BioNTech and Moderna vaccines. All three are currently being rolled out for broader use across the United States.

Learn more about Emergency Use Authorization >

Who can get vaccinated right now?

The distribution of vaccines will be in accordance with the guidelines from the Advisory Committee on Immunization Practices (ACIP) as well as Massachusetts’ COVID-19 Vaccination Plan.

There are four recommended phases of vaccine distribution. The ACIP released that Phase 1a of vaccine distribution will include health care workers and long-term care facility residents. Given that guidance, the Massachusetts Department of Public Health is prioritizing hospitals, long term care facilities—including skilled nursing facilities—emergency medical services and other health care providers for recruitment and enrollment in the Massachusetts COVID-19 Vaccination Program.

Learn more about Massachusetts' Vaccine Distribution Plan >

When will I be able to get vaccinated against COVID-19?

Frontline health care workers, residents and staff of skilled nursing facilities and assisted living residences are currently being vaccinated as part of the first phase. Massachusetts estimates that the general public can get the vaccine between April-June 2021. If you are higher risk, are 65 or older, or work in certain jobs like education, transit or public works, you might receive the vaccine sooner. The current phases of COVID-19 vaccination and the approximate timelines for residents of Massachusetts are detailed here.

We know that many of you are eager to get the COVID-19 vaccine. Mass General Brigham is committed to getting all of our patients vaccinated as soon as possible. Our current vaccine supply is limited to what we receive from the Commonwealth of Massachusetts each week in accordance with its vaccination phases. 

We will contact eligible patients through Patient Gateway, e-mail, text message or phone call. All scheduling is being handled centrally, so please do not contact your doctor’s office about scheduling vaccine appointments. For the latest information on the COVID-19 vaccine, click here. 

As we continue to wait for new vaccines to be delivered, we ask that you remain diligent. It is important to continue to wash your hands, wear a mask, and socially distance, whether you or someone you know has been vaccinated.

Will the COVID-19 vaccine be safe and effective?

Yes. In the U.S. the FDA reviews data collected throughout the development of the vaccine and from clinical trials before approving the vaccine for use. The three vaccines that received EUA from the FDA have been shown in clinical studies to be very effective at preventing severe illness, hospitalization and death. As people receive the vaccine, the FDA continues to closely monitor its safety and effectiveness.

How many shots will I need to get?

The Johnson & Johnson vaccine requires a single dose. The Pfizer/BioNTech and Moderna vaccines both require two shots, or doses. The Pfizer/BioNTech vaccine requires a minimum of 21 days between the first and second dose; the Moderna vaccine requires a minimum of 28 days between the first and second dose.

Is one of the COVID-19 vaccines better than the other? Will I have a choice of which vaccine I receive?

No. The three vaccines that received EUA from the FDA have been shown in clinical studies to be very effective at preventing severe illness, hospitalization and death. All vaccines are currently being shipped across the nation and people receiving the vaccination will not have the option to select which vaccine they receive. Once you receive your first shot, your second shot will be from the same manufacturer, i.e. if your first shot is from Pfizer/BioNTech, your second dose will be as well.

How much will a vaccine reduce the risk of COVID-19 and its complications?

Both vaccines that received EUA in December contain mRNA (messenger RNA) and have now been given to millions of people around the world. We are learning so much more about their safety and efficacy profiles. Much of this new data confirm the safety and efficacy of these vaccines that was seen in the initial clinical trials. Typically, a vaccine trains your body to recognize and respond to proteins produced by a bacteria or virus. mRNA vaccines trick your body into producing the protein itself which causes your immune system to detect these proteins and defend itself, without risking the serious consequences of getting sick with COVID-19.

While the current COVID-19 vaccines reduce the risk of the vaccinated person becoming seriously ill with COVID-19, we still do not yet know for sure whether the Johnson and Johnson, Pfizer/BioNTech or Moderna vaccines will reduce transmission of the virus from one individual to another. We will be learning this as the vaccines are rolled out to more and more individuals.

Could I have an adverse reaction or side effect from the vaccine? What should I do if I experience one?

Based on what we know so far, many people will have mild, short-term side effects after getting a COVID-19 vaccine including:
  • fever
  • fatigue
  • headache
  • muscle pain 
  • joint pain
Some patients may have swelling and redness at the site of the injection that can last for a few days. These are not allergic symptoms but part of the immune response to the vaccine.

In rare instances, vaccines can cause severe physical reactions. If you experience an adverse reaction or side effect, you should contact your physician. Additionally, the Centers for Disease Control and Prevention (CDC) and FDA encourage the public to report possible side effects (called adverse events) to the Vaccine Adverse Event Reporting System (VAERS). Reports to VAERS help the CDC monitor the safety of vaccines. Safety is a top priority.

Learn more the difference between a vaccine side effect and an adverse event >

If I get the vaccine do I still need to wear a mask and practice social distancing?

Yes. According to the CDC, there is not enough information currently available to say if or when the CDC will stop recommending that people wear masks and avoid close contact with others to help prevent the spread of the virus that causes COVID-19. Additionally, how many people get vaccinated and how the virus is spreading in communities will also impact the effectiveness of the vaccine.

How soon after getting the vaccine am I protected?

The Pfizer/BioNTech vaccine has been shown to start providing some protection for the vaccinated person within 10 days of receiving the first dose. However, it remains necessary to receive the second dose in order for the vaccine to be maximally effective in protecting the vaccinated person. It is important for vaccinated individuals to continue wearing masks and following social distancing guidelines to help prevent the spread of the virus to other individuals.

Where can I find more information?

The CDC provides additional information on COVID-19 vaccines and responses to common questions.