How Are Vaccines Approved?

The topic of a vaccine to combat the COVID-19 pandemic is dominating the news. While the prospect of a vaccine is encouraging, many people have questions about how the COVID vaccine, or any vaccine, is tested and approved for use on humans.

The good news is this: No vaccine is approved by the U.S. Food and Drug Administration without rigorous and extensive development in laboratories, as well as animal studies and testing on people, to make sure they are safe and effective.

FDA scientists with extensive training thoroughly evaluate any vaccine before deciding whether to license (approve) it for use in the United States. The FDA considers all the ingredients in the vaccine, both active ingredients and other substances, before giving its approval. And even after the vaccine is released to the public, the FDA continues to monitor it for safety.

Monitoring of the vaccine and how it’s produced, including regular facility inspections, must continue for as long as the manufacturer holds a license for the vaccine.

The sponsor of a new vaccine follows a multi-layered approval process, which includes an investigational new drug application, clinical trials, inspection of the manufacturing facility and presentation of findings to FDA’s Vaccines and Related Biological Products Advisory Committee.

Clinical trials on humans are divided into three phases. Adults are always tested first before children.

• In Phase 1, the vaccine is given to healthy, adult volunteers. This phase helps scientists understand if the vaccine is safe, if it seems to work, if there are serious side effects and if the size of the dose seems related to any side effects.
• In Phase 2, more adult volunteers receive the vaccine. Scientists are looking for the most common short-term side effects and how the volunteers’ immune systems are responding to the virus.
• In the final phase, Phase 3, scientists examine more volunteers to see how people who do receive the vaccine fare compared with people who don’t receive the vaccine. They determine if the vaccine is safe, if it is effective, and what the most common side effects are.

The FDA licenses the vaccine only if it is determined to be safe and effective, and only if the benefits outweigh the risks.

Vaccines are made in batches, called “lots.’’ Vaccine manufacturers must test all lots to make sure they are safe, pure and effective. Lots cannot be released without FDA approval.

Once the FDA has approved a COVID-19 vaccine for release, Ochsner Health supports and highly encourages widespread vaccination for all employees and our patients. Ochsner will only recommend and administer vaccines that FDA has certified as safe and effective for all patients and employees, including our most vulnerable populations. Ochsner’s contributions to the vaccine trials have helped illustrate their safety to the FDA. Large-scale vaccination of our community is the best way to keep everyone safe and to end the COVID-19 pandemic.

What about news reports regarding vaccine trials that were paused?

It’s normal for all clinical trials to pause and take a closer look at symptoms participants develop to see if they are possible side effects. Sometimes, the symptoms have nothing to do with the actual product. This process is in place to ensure that any product brought to the public is as safe as possible.

Vaccines work to prevent disease by exposing an individual to a relatively safe and small amount of inactivated virus. This stimulates your body’s immune system to mount a response as if it were a true infection, minimizing your risk of re-infection or disease burden should you encounter the same virus later.

The information in this blog post is accurate at the time of publication. However, as the situation surrounding COVID-19 continues to change, it's possible that information has changed since being published. While Ochsner Health is trying to keep our blog posts as up-to-date as possible, we also encourage readers to stay informed on news and recommendations by using the CDC website.