Longitudinal dynamics of SARS-CoV-2 anti–receptor binding domain IgG antibodies in a wide population of health care workers after BNT162b2 vaccination. (September 2022)

• Record Type: Journal Article
• Authors: Bordi, Licia; Sberna, Giuseppe; Piscioneri, Cesira Natalina; Cocchiara, Rosario Andrea; Miani, Anna; Grammatico, Paola; Mariani, Bruno; Parisi, Gabriella
• Is Part Of: International journal of infectious diseases. Volume 122(2022)
• Page Start: 174
• Page End: 177
• Publication Date: 2022-09
• Subjects: SARS-CoV-2 -- Humoral Response -- Anti-RBD IgG -- BNT162b2 -- Health care workers; Communicable diseases -- Periodicals; Communicable Diseases -- Periodicals; Communicable diseases; Periodicals; Electronic journals; 616.9
• DOI: 10.1016/j.ijid.2022.05.061
• Languages: English
• ISSNs: 1201-9712

Abstract

Highlights: Anti–receptor-binding domain (RBD) antibodies decrease after 9 months following the second dose of BNT162b2. Females exhibited a better ability to produce anti-RBD IgG 1 and 9 months after vaccination. Importance of the choice of having increased the number of vaccine doses to three. Abstract: Objectives: With the availability of vaccines, commercial assays detecting anti–severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies evolved toward quantitative assays directed to the spike glycoprotein or its receptor-binding domain (RBD). The objective was to perform a large-scale, longitudinal study involving health care workers (HCWs), with the aim of establishing the kinetics of immune response throughout the 9-month period after receipt of the second dose of the BNT162b2 vaccine. Methods: Quantitative determination of immunoglobulin (Ig) G antibodies against the RBD of the S1 subunit of the spike protein of SARS-CoV-2 on the Alinity systems. Results: The highest levels of anti-RBD IgG were measured after 1 month from full vaccination (median: 1432 binding antibody units/ml [BAU/ml]); subsequently, a steep decrease (7.4-fold decrease) in IgG levels was observed at 6 months (median: 194.3 BAU/ml), with a further 2.5-fold decrease at 9 months (median: 79.3 BAU/ml). Furthermore, the same data, when analyzed for sex, showed significant differences between male and female participants at both 1 and 9 months from vaccination, but not at 6 months. Conclusion: Our results confirm the tendency of anti-RBD antibodies to decrease over time, also when extending the analysis up to 9 months, and highlight a better ability of the female sex to produce antibodies 1 month and 9 months after vaccination. Overall, these data, obtained in a wide population of HCWs, support the importance of having increased the vaccine doses.