Safety & Effectiveness
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 will be among the first to get 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.
The vaccines 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.
The U.S. vaccine safety system ensures that all vaccines are as safe as possible. Safety is a top priority while federal partners work to make this and other COVID-19 vaccines available.