The Pfizer/BioNTech and Moderna COVID-19 vaccines have received full approval by the Food and Drug Administration (FDA).

Lisa Maragakis, M.D., M.P.H., senior director of infection prevention, and Gabor Kelen, M.D., director of the Johns Hopkins Office of Critical Event Preparedness and Response, explain what that means.

What does full FDA approval of a COVID-19 vaccine mean?

Review for full FDA approval is a normal step in the process of making a vaccine available for the public.

Full FDA approval takes place when enough data demonstrate that the vaccines are safe and effective for most people who receive them, and when the FDA has had an opportunity to review and approve the whole vaccine manufacturing process and facilities. After many months of studies and more than 500 million COVID-19 vaccines being given in the U.S., the FDA has a lot of information on how safe and effective the vaccines are in protecting people, how well they work to prevent severe coronavirus disease, and how the vaccines are safely and consistently manufactured. 

COVID Vaccines: Emergency Use Authorization vs. Approval

Not every vaccine is granted an emergency use authorization before full approval. The FDA authorized three COVID-19 vaccines (Pfizer, Moderna and Johnson & Johnson) to answer an urgent need to protect people from the coronavirus pandemic, which was (and continues to be) a public health emergency.

And not every authorized vaccine becomes fully approved. For example, in December 2021, due to potential blood clots following administration of the Johnson & Johnson vaccine, the CDC updated its recommendations. The CDC noted that the two mRNA vaccines from Pfizer and Moderna are preferred over the Johnson & Johnson vaccine, which remains available for those who prefer it and for use in certain circumstances.

Full approval is granted when, over time, the FDA has amassed even more scientific evidence to support use of the COVID-19 vaccines, showing that the benefits of the vaccine are greater than its risks, and that the vaccines can be manufactured reliably, safely and with consistent quality.

Using Data to Approve COVID-19 Vaccines

Hundreds of millions of COVID-19 vaccine doses have been given to people in countries all over the world.

People who get the vaccines are encouraged to report any problems, including any severe side effects. A cooperative effort between the U.S. Centers for Disease Control and Prevention (CDC) and the FDA, the Vaccine Adverse Event Reporting System (VAERS) collects and analyzes reports from people who received a vaccination and who experienced an adverse event, such as a severe side effect, after getting the shot.

As a result, we now have even more evidence that the two FDA-approved COVID-19 vaccines are safe for most people who receive them, and that they work well to help prevent severe coronavirus disease, hospitalization or death.

Like other fully approved vaccines used to help prevent illnesses, the FDA-authorized COVID-19 vaccines can cause temporary aches, pains and fever in some people, but the risk of serious side effects is extremely low. 

FDA and the Vaccine Review Process

For over a century, FDA-authorized and approved vaccines have prevented potentially serious diseases such as measles, influenza and whooping cough. Vaccinations have helped reduce and prevent deadly outbreaks of smallpox and polio. The approval system for vaccines uses scientific data and exacting standards to ensure safe and effective vaccines. These review process includes: 

• Clinical trials. The FDA requires rigorous testing of vaccines through a series of clinical trials to make sure they work and are safe before authorizing or approving them for the public. The laboratories that conduct the trials are independent from the vaccine companies and the government, so the information they convey to the FDA for its approval process is not biased.
• Risks and benefits. FDA approval of a vaccine involves careful assessment of risks and benefits. Before approval can happen, the clinical trials and other data used by the agency must demonstrate that the benefits of a vaccine are greater than its risks for those who will be vaccinated.
• Continual monitoring. After authorization or approval, monitoring continues: The FDA continues to examine data for adverse effects among the people receiving the vaccine. If any problems are linked to a vaccine, the FDA may pause the administration of that vaccine to do more studies and ensure that the problem does not outweigh the vaccine’s benefit.
• Manufacturing guidelines. The FDA also sets strict guidelines for vaccine manufacturers and requires that they test the vaccine doses in batches (lots) to ensure the quality and effectiveness of the vaccines remain consistent and reliable.

Learn more about COVID-19 vaccine safety and side effects.