Declining neutralizing antibody levels after SARS-CoV-2 mRNA vaccination: observational data from community point-of-care testing service in Brno, Czechia.

Objectives: Understanding immune response is critical for control of COVID-19 pandemic. However, recent studies show that vaccine-induced humoral immunity may not be long-lasting and weaker in SARS-CoV-2 variants of concern.

Methods: In May 2021, 253 self-nominated persons were tested for antibodies against SARS-CoV-2 in 1 to 104 days (mean 41, median 28) after two doses of Moderna and Pfizer-BioNTech vaccines in the city of Brno, Czechia.