Prior receipt of the vaccine will not affect the results of SARS-CoV-2 nucleic acid amplification or antigen tests for diagnosis of acute/current SARS-CoV-2 infection.
The vaccine contains mRNA that encodes the spike protein; thus, a positive test for spike protein IgM or IgG could indicate either prior infection or prior vaccination.
To evaluate for evidence of prior infection in an individual who has received the BNT162b2 vaccine, a test that specifically evaluates IgM or IgG to the nucleocapsid protein should be used. A positive nucleocapsid protein-based assay indicates prior infection.
Antibody testing is not currently recommended to assess immunity to COVID-19 following BNT162b2 vaccination.
Role of vaccines among other preventive measures:
As there is not yet any evidence of an effect of the vaccine on transmission, non-pharmaceutical interventions must continue, including use of face masks, physical distancing, handwashing and other measures based on the epidemiology of SARS-CoV-2 in particular settings.
Government advice on non-pharmaceutical interventions should continue to be followed by vaccinated individuals, as well as those who have not yet been vaccinated.
Link to the related WHO news release:
Link to NEJM article presenting the safety and efficacy of BNT162b2 mRNA COVID-19 vaccine: