Differential Dynamics of Humoral and Cell-Mediated Immunity with Three Doses of BNT162b2 SARS-CoV-2 Vaccine in Healthcare Workers in Japan: A Prospective Cohort Study

• Published in: Vaccines (Basel) Vol. 10; no. 7; p. 1050
• Main Authors: Yamashita, Keita, Suzuki, Akira, Takebayashi, Shiori, Toguchi, Akihiro, Ogitani, Kenya, Niizeki, Noriyasu, Nagura, Osanori, Furuhashi, Kazuki, Iwaizumi, Moriya, Maekawa, Masato
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30.06.2022; MDPI
• Subjects: anti-RBD antibody; Antibodies; Antigens; Automation; Avidity; BNT162b2 vaccine; Cell-mediated immunity; Cohort analysis; Coronaviruses; Correlation coefficient; Correlation coefficients; COVID-19; COVID-19 vaccines; ELISpot; Enzyme-linked immunosorbent assay; Enzymes; Health care; Humoral immunity; Immunity; Immunoassay; Immunoglobulin G; Immunoglobulins; Infections; Laboratories; Medical personnel; mRNA; mRNA vaccines; Proteins; Reagents; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Vaccines; United Kingdom > UK; United States > US; Japan
• ISSN: 2076-393X; 2076-393X
• DOI: 10.3390/vaccines10071050

Vaccines against SARS-CoV-2 with good efficacy are now available worldwide. However, gained immunity diminishes over time. Here, we investigate the course of both humoral and cell-mediated immunity in response to three doses of the Pfizer mRNA BNT162b2 SARS-CoV-2 vaccine in healthcare workers in Japan. SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies (total Ig, IgG), neutralizing antibodies (NAb), and ELISpot were measured in serum and whole blood samples collected after each vaccine dose. ELISpot numbers were higher than the cutoff values in most participants at all times. It was suggested that the difference in behavior between humoral immunity and cell-mediated immunity with age is complementary. Anti-RBD total Ig, IgG, and NAb indicated a high correlation at each time point after vaccine doses. Total Ig was retained long-term after the second dose and increased significantly faster by the booster dose than IgG. Nab levels of all subjects were ≤20% six months after the second dose, and the correlation coefficient was greatly reduced. These are due to the avidity of each antibody and differences among commercial kits, which may affect the evaluation of immunokinetics in previous COVID-19 studies. Therefore, it is necessary to harmonize reagents categorized by the same characteristics.