Uninformative and unuseful: why it is necessary to actively challenge COVID-19 antibody testing postvaccination.

Abstract Objectives We aimed to assess the evidence on the usefulness of postvaccination testing of COVID-19 antibodies. Study design We used a descriptive analytical approach. Methods We synthesized insights of studies on the immunological responses to SARS-CoV-2 after natural infection or vaccination and recommendations by regulatory institutions, such as the Food and Drug Administration and the Centers for Disease Control and Prevention in the United States. Results Based on the multiple humoral and cellular responses elicited by either the virus or the vaccines, the high variability of antibodies in blood, and the lack of correlation between the presence of antibodies and active cellular immunity against SARS-CoV-2, there has been explicit advice against assessing immunological status postvaccination. Conclusions Postvaccination antibody testing is not warranted to assess immunity status for COVID-19. Patients may misinterpret results, leading to the spread of misinformation regarding vaccine efficacy or the need to continue self-protection or the protection of others. Therefore, public health authorities should actively challenge the promotion and commercialization of this type of tests.