On August 23, the U.S. Food and Drug Administration (FDA) approved the first COVID-19 vaccine. The vaccine has been known as the Pfizer-BioNTech COVID-19 vaccine, and will now be marketed as Comirnaty, for the prevention of COVID-19 disease in individuals aged 16 years and older. The vaccine also continues to be available under emergency use authorization (EUA), including for individuals aged 12 to 15 years and for the administration of a third dose in certain immunocompromised individuals.
Pandemic Milestone
“The FDA’s approval of this vaccine is a milestone as we continue to battle the COVID-19 pandemic. While this and other vaccines have met the FDA’s rigorous scientific standards for EUA, as the first FDA-approved COVID-19 vaccine, the public can be very confident that this vaccine meets the high standards for safety, effectiveness, and manufacturing quality the FDA requires of an approved product,” said Acting FDA Commissioner Janet Woodcock, MD. “While millions of people have already safely received COVID-19 vaccines, we recognize that for some, the FDA approval of a vaccine may now instill additional confidence to get vaccinated. [This] milestone puts us one step closer to altering the course of this pandemic in the United States.”
Since December 11, 2020, the Pfizer-BioNTech COVID-19 vaccine has been available under EUA in individuals aged 16 years and older, and the authorization was expanded to include those aged 12 to 15 years on May 10, 2021. EUAs can be used by the FDA during public health emergencies to provide access to medical products that may be effective in preventing, diagnosing, or treating a disease, provided that the FDA determines that the known and potential benefits of a product—when used to prevent, diagnose, or treat the disease—outweigh the known and potential risks of the product.
FDA-approved vaccines undergo the agency’s standard process for reviewing the quality, safety, and effectiveness of medical products. For all vaccines, the FDA evaluates data and information included in the manufacturer’s submission of a biologics license application. For the Pfizer-BioNTech COVID-19 vaccine, the biologics license application builds on the extensive data and information previously submitted that supported the EUA, such as preclinical and clinical data and information, as well as details of the manufacturing process, vaccine testing results to ensure vaccine quality, and inspections of the sites where the vaccine is made. The agency conducts its own analyses of the information in the biologics license application to make sure the vaccine is safe and effective and meets the FDA’s standards for approval.
Underlying Mechanism
The Pfizer-BioNTech COVID-19 vaccine contains messenger RNA (mRNA). The mRNA is used by the body to make a mimic of one of the proteins in the virus that causes COVID-19. The result of a person receiving this vaccine is that their immune system will ultimately react defensively to the virus that causes COVID-19. The mRNA in the Pfizer-BioNTech COVID-19 vaccine is only present in the body for a short time and is not incorporated into, nor does it alter, an individual’s genetic material. The Pfizer-BioNTech COVID-19 vaccine has the same formulation as the EUA vaccine and is administered as a series of two doses 3 weeks apart.
“Our scientific and medical experts conducted an incredibly thorough and thoughtful evaluation of this vaccine. We evaluated scientific data and information included in hundreds of thousands of pages, conducted our own analyses of [the vaccine’s] safety and effectiveness, and performed a detailed assessment of the manufacturing processes, including inspections of the manufacturing facilities,” said Peter Marks, MD, PhD, director of FDA’s Center for Biologics Evaluation and Research. “We have not lost sight that the COVID-19 public health crisis continues in the U.S. and that the public is counting on safe and effective vaccines. The public and medical community can be confident that although we approved this vaccine expeditiously, it was fully in keeping with our existing high standards for vaccines in the United States."
FDA Evaluation of Safety and Effectiveness Data for Approval
The first EUA for the Pfizer-BioNTech COVID-19 Vaccine for individuals aged 16 years and older was based on safety and effectiveness data from a randomized, controlled, blinded ongoing clinical trial of thousands of individuals.
To support the FDA’s approval decision today, the FDA reviewed updated data from the clinical trial that supported the EUA and included a longer duration of follow-up in a larger clinical trial population. Specifically, in the FDA’s review for approval, the agency analyzed effectiveness data from approximately 20,000 vaccine and 20,000 placebo recipients ages 16 and older who did not have evidence of the COVID-19 virus infection within a week of receiving the second dose. Based on results from the clinical trial, the vaccine was 91% effective in preventing COVID-19 disease.
The safety of the Pfizer-BioNTech COVID-19 vaccine was evaluated in approximately 22,000 people who received the vaccine and 22,000 people who received a placebo. More than half of the clinical trial participants were followed for safety outcomes for at least 4 months after the second dose. Overall, approximately 12,000 recipients have been followed for at least 6 months.
The most commonly reported side effects by those clinical trial participants who received the Pfizer-BioNTech COVID-19 vaccine were pain, redness and swelling at the injection site, fatigue, headache, muscle or joint pain, chills, and fever. The vaccine is effective in preventing COVID-19 and potentially serious outcomes including hospitalization and death.
Additionally, the FDA conducted a rigorous evaluation of the postauthorization safety surveillance data pertaining to myocarditis and pericarditis following administration of the Pfizer-BioNTech COVID-19 vaccine and has determined that the data demonstrate increased risks, particularly within the 7 days following the second dose. The observed risk is higher among males aged younger than 40 compared to females and older males. The observed risk is highest in males aged 12 through 17 years. Available data from short-term follow-up suggest that most individuals have had resolution of symptoms; however, some individuals required intensive care support. Information is not yet available about potential long-term health outcomes. The Pfizer-BioNTech COVID-19 vaccine Prescribing Information includes a warning about these risks.
Ongoing Safety Monitoring
The FDA and Centers for Disease Control and Prevention have monitoring systems in place to ensure that any safety concerns continue to be identified and evaluated in a timely manner. In addition, the FDA is requiring the manufacturer to conduct postmarketing studies to further assess the risks of myocarditis and pericarditis following vaccination with the Pfizer-BioNTech COVID-19 vaccine. These studies will include an evaluation of long-term outcomes among individuals who develop myocarditis following vaccination.
Finally, although not FDA requirements, the company has committed to additional postmarketing safety studies, including conducting a pregnancy registry study to evaluate pregnancy and infant outcomes after receipt of the Pfizer-BioNTech COVID-19 vaccine during pregnancy.
