Vaccine Safety & Effectiveness
We are confident that the vaccines approved for use in the U.S. are highly safe and effective. Both were developed in the United States and have undergone U.S. Food and Drug Administration (FDA) scrutiny, the most rigorous vaccine approval process on the planet. They were found to be over 94% effective in adults, and only 2-10% of clinical trial participants experienced mild to moderate side effects attributable to a normal, healthy immune response.
Stephen M. Hahn, M.D., FDA Commissioner, and Peter Marks, M.D., Ph.D., Director, Center for Biologics Evaluation and Research
Vaccine Development & Approval Process
Each COVID-19 vaccine moved through a three-phase development process, including human clinical trials involving tens of thousands of people. Upon the completion of the clinical trials, the drug sponsors applied to the FDA to market and distribute the vaccine.
Prior to issuing guidance on each vaccine, the data and evidence was reviewed by an external panel of independent experts who provided a recommendation to the FDA to authorize the vaccine. The FDA ultimately determined that the safety and effectiveness of the vaccines, product quality, and consistency had been clearly demonstrated, so the vaccines were approved. While the three-phase clinical trial process has historically taken an average of three years or more, the FDA allowed for the acceleration of the development timeline and permitted some trials to overlap rather than run sequentially.
But federal oversight does not end once the vaccines are approved. Local healthcare workers are among the first receiving the vaccine and they will be using an after-vaccine health checker to provide additional data to a national database. Anyone who gets the vaccine may also use the vaccine reporting system – VAERS – to report undocumented side effects. This system is already used with other vaccines and immediately alerts health authorities to any possible issues.
Based on published data, there are mild to moderate side effects associated with the leading COVID-19 vaccines. These short-term symptoms can include:
- Headache, and
- Joint and muscle pain
However, only 2-10% of people who took part in the clinical trials experienced side effects. None were severe or required hospitalization.
Side effects from vaccines are not uncommon. The seasonal flu shot, for example, can cause fever and fatigue, among other symptoms.
The COVID-19 vaccines, in particular, are designed to teach your body how to recognize and fight the coronavirus. Therefore, mild to moderate side effects are the result of a normal, healthy immune system responding to the vaccine.
Side effects do not mean you have contracted COVID-19. You cannot get COVID-19 from the vaccine. Remember, mild to moderate symptoms are a sign that the body is building immunity.
Visit the Centers for Disease Control and Prevention website to learn more about the COVID-19 side effects.
- Are the COVID-19 vaccines safe?
We are confident that the vaccines currently approved for use in the U.S. are highly safe and effective. Both were developed in the U.S. and have undergone U.S. Food and Drug Administration (FDA) scrutiny, the most rigorous vaccine approval process on the planet.
Like other medications, the COVID-19 vaccines can have some side effects, but all symptoms experienced by trial participants were mild or moderate and were attributable to a normal, healthy immune response. The most commonly reported side effects of the vaccine were fatigue, muscle or joint pain, and headache—all among less than 10 percent of trial participants. None were severe nor required hospitalization.
The COVID-19 vaccines DO NOT use the live virus that causes COVID-19, so you cannot get COVID-19 from the vaccine.
- Are the COVID-19 vaccines effective?
Both the Pfizer and Moderna vaccines are over 94 percent effective, a calculation based on observed infection rates among unvaccinated (placebo) adult participants compared to vaccinated participants in each clinical trial. Efficacy was consistent across age (16+), gender, race and ethnicity demographics. The vaccines have not yet been widely tested in children and adolescents under 16.
- Can children and pregnant women be vaccinated?
COVID-19 vaccine trials for children are just beginning. Pfizer expanded its vaccine testing to children ages 12 and older in late October; however, Moderna has not yet set a date when it will begin testing its product in children. It remains unclear when a vaccine will be approved for children under 16 but the goal is to have one ready before the 2021 school year.
Pregnant women, on the other hand, were not included in any of the early clinical trials. Clinical trials continue to expand, and we will update this website as information becomes available.