New medications, vaccines (shots), and treatments may make you feel uncertain, but they are studied and evaluated with safety and effectiveness as the top priority. Vaccines (shots) undergo rigorous testing and must meet safety standards before being released. In addition to the clinical trials completed as part of the routine process, the vaccines (shots) will continue to be evaluated by the manufacturers and researchers over time in the real world. More information is available at https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety.html.