Antibody Titers Before and After a Third Dose of the SARS-CoV-2 BNT162b2 Vaccine in Adults Aged ≥60 Years

The durability of response to the SARS-CoV-2 BNT162b2 vaccine (Pfizer-BioNTech) in adults aged 60 years and older has yet to be determined. The immune response to 2 doses of BNT162b2 is lower in individuals aged 65 to 85 years vs 18 to 55 years. 1 Among 4868 health care workers receiving 2 BNT162b2 doses, a significant waning of the humoral response (IgG, neutralizing antibodies) within 6 months of the second dose was observed, especially among adults aged 65 years and older. 2 After a fourth SARS-CoV-2 wave in Israel, the Israeli Ministry of Health authorized, at the end of July 2021, a third BNT162b2 vaccine dose for individuals aged 60 years and older, which was subsequently expanded to younger age groups.