If I get the COVID-19 vaccine, will I become a false positive for COVID-19 testing (e.g., PCR test, antigen test or antibody test)?

Receiving the COVID-19 vaccine will not affect the PCR or antigen test results because these tests check for active disease, not immunity. There is no virus present in the mRNA COVID-19 vaccine.

The vaccine is intended to cause an immune response, so the serology test (antibody test) may be positive in someone who has been vaccinated.

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https://www.manitobavaccine.ca/answers/will-i-test-positive-for-covid-if-i-get-the-vaccine/