Humoral response against spike protein enhanced by fifth and sixth COVID-19 mRNA vaccine in the uninfected and infected subjects

• Main Authors: Hideaki Kato (Author), Takayuki Kurosawa (Author), Kazuo Horikawa (Author), Yayoi Kimura (Author), Kei Miyakawa (Author), Akihide Ryo (Author), Atsushi Goto (Author)
• Format: Book
• Published: Taylor & Francis Group, 2023-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

ABSTRACTAntibody obtained by the coronavirus disease-19 (COVID-19) mRNA vaccine declines over time, and additional vaccinations are offered. It is not clear how repeated vaccination affects humoral immunity in uninfected individuals. We analyzed immunoglobulin G for spike protein (S-IgG) titers in COVID-19 uninfected and infected individuals vaccinated up to six times. The geometric mean S-IgG titers were 575.9 AU/mL and 369.0 AU/mL in those who received 6 and 5 doses less than 180 days after the last vaccination in uninfected subjects. In the 180-360 days after the last vaccination, the geometric mean S-IgG titers were 237.9 AU/mL and 128.6 AU/mL in the uninfected subjects who underwent five-dose and four-dose groups, respectively. Multivariate analysis showed that S-IgG titer increased 1.261-fold with each additional dose of mRNA vaccine. The S-IgG titers were 2.039-fold higher in the COVID-infected subjects compared to uninfected subjects. The positivity rate of nucleocapsid antibodies, suggesting a history of COVID-19, decreased 82% and 30% of COVID-infected cases after 180 and 360 days of infection, respectively. This result suggested that repeated vaccination with the COVID-19 mRNA vaccine may increase antibody titer in uninfected subjects.

Item Description

10.1080/21645515.2023.2278376
2164-554X
2164-5515