COVID-19 Vaccines Will the COVID-19 vaccine cause you to test positive? https://www.cdc.gov/coronavirus/2019-ncov/vaccines/vaccine-benefits/facts.html No, vaccines currently in clinical trials in the United States will not cause patients to test positive on the viral test used to detect infection. Since the vaccine does not cause patients to test positive for the COVID-19 viral test, testing remains the best way to rule out an active infection should symptoms develop post-vaccination. If these symptoms develop, appropriate quarantine should be practiced until active infection is ruled out. SHARE News & Knowledge All Curi recommendations are based on current CDC criteria at the time of publication. CDC guidance for SARS-CoV-2 infection may, or may not, be adopted by state and local health departments to respond to rapidly changing local circumstances. Providers should always check with their local health department to see if the CDC’s guidance on any given topic has been modified (particularly if more restrictive) from the CDC’s recommended guidelines. Follow this link https://www.cdc.gov/publichealthgateway/healthdirectories/index.html for contact information to your state/local health department. If local recommendations vary from those of the CDC, and you are unsure what recommendations to follow, then it is safer to follow the more restrictive guidelines/recommendations.