For this post, the Department of Quality and Safety asked George X. Huang, MD, a fellow in the Division of Allergy and Clinical Immunology, and Paige Wickner, MD, MPH, a faculty member and the head of Quality and Safety for the Division of Allergy and Clinical Immunology at Brigham and Women’s Hospital, to provide information about the Pfizer-BioNTech COVID-19 vaccine.

On Dec. 11, 2020, the U.S. Food and Drug Administration (FDA) approved an Emergency Use Authorization for the COVID-19 vaccine produced by Pfizer and BioNTech to be distributed in the United States to those ages 16 and older.1 This vaccine (which is called BNT162b2) is delivered via two injections to the arm muscle which are given three weeks apart. The vaccine works by using advanced technology to deliver an RNA molecule to the body, which then instructs it to make a modified version of the spike protein of the SARS-CoV-2 virus.

Although researchers have been studying them for many years, this is the first RNA-based vaccine to be approved in the U.S. RNA-based vaccines are generally considered safer than other vaccines as they are not produced using any infectious virus elements, and the benefits of RNA-based vaccines are the same as all other vaccines: those vaccinated gain protection against certain infectious diseases. Moderna, another biotechnology company, has also produced an RNA-based COVID-19 vaccine that is currently under review by the FDA.

To study their vaccine’s safety and efficacy, Pfizer conducted clinical trials which included over 43,000 participants from several different countries including the U.S., Argentina, Brazil, and South Africa. Data from these trials showed that the vaccine prevented 95 percent of COVID-19 infections compared to participants who received a “fake” vaccine, also known as a placebo.2

There will certainly be further developments as other companies’ COVID-19 vaccines undergo review by the FDA. At the Brigham, we are closely following all data related to these vaccines, including their efficacy and safety. We have put measures in place as we begin vaccinations to ensure the safety of our patients and staff. Based on recommendations by the Centers for Disease Control (CDC), and in alignment with the state’s approach to vaccine distribution, we have begun vaccinating eligible health care workers this week.

For additional information on COVID-19 vaccines, please reference the links below in addition to consulting state-specific guidelines:


    1. U.S. Food & Drug Administration. Pfizer-BioNTech COVID-19 Vaccine.
    2. Polack et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N  Engl J Med. 2020. PMID: 33301246