Humoral and cellular responses to the third COVID-19 BNT162b2 vaccine dose in research institute workers in Japan

We read with interest the article on SARS-CoV-2 antibody and T cell responses after first and second vaccination among healthcare workers by Mak et al. [1]. Cellular immunity was reportedly not necessarily related with humoral immunity, while T cell responses and anti-spike IgG (S-IgG) levels increased after vaccination. SARS-CoV-2 T cell response and S-IgG levels were also investigated before and after the third BNT162b2 (Pfizer-BioNTech) vaccine dose with an employee cohort of the National Center for Geriatrics and Gerontology (NCGG), consisting of a hospital and a research institute in Japan.