Noa Eliakim-Raz, Amos Stemmer, Yaara Leibovici-Weisman, Asaf Ness, Muhammad Awwad, Nassem Ghantous, Noam Erez, Avital Bareket-Samish, Adva Levy-Barda, Haim Ben-Zvi, Neta Moskovits, Erez Bar-Haim, and Salomon M Stemmer
ObjectiveTo evaluate the durability of response 3 months after the third BNT162b2 vaccine in adults aged 60 years and older.DesignProspective cohort study.SettingSingle tertiary centre.ParticipantsHealthcare workers/family members aged ≥60 years old who received the third BNT162b2 dose.InterventionsBlood samples were drawn immediately before (T0), 10–19 days (T1) and 74–103 days (T2) after the third dose.Primary and secondary outcome measuresAnti-spike IgG titres were determined using a commercial assay and seropositivity was defined as ≥50 arbitrary units (AU)/mL. Neutralising antibody titres were determined at T2. Adverse events, COVID-19 infections and Clinical Frailty Scale (CFS) levels were documented.ResultsThe analysis included 97 participants (median age, 70 years (IQR, 66–74), 58% CFS level 2). IgG titres, which increased significantly from T0 to T1 (median, 440 AU/mL (IQR, 294–923) and median, 25 429 AU/mL (IQR, 14 203–36 114), respectively; pConclusionsAnti-spike IgG and neutralising antibody levels remain adequate 3 months after the third BNT162b2 vaccine in healthy adults aged ≥60 years, although the decline in IgG is concerning. A third dose of vaccine in this population should be top priority.