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Attenuation of Antibody Titers from 3 to 6 Months after the Second Dose of the BNT162b2 Vaccine Depends on Sex, with Age and Smoking Risk Factors for Lower Antibody Titers at 6 Months

Authors :
Yushi Nomura
Michiru Sawahata
Yosikazu Nakamura
Ryousuke Koike
Otohiro Katsube
Koichi Hagiwara
Seiji Niho
Norihiro Masuda
Takaaki Tanaka
Kumiya Sugiyama
Source :
Vaccines, Vol 9, Iss 12, p 1500 (2021)
Publication Year :
2021
Publisher :
MDPI AG, 2021.

Abstract

Objective: We aimed to determine antibody titers at six months and their percentage change from three to six months after the second dose of the BNT162b2 coronavirus disease 2019 (COVID-19) mRNA vaccine (Pfizer/BioNTech) and to explore clinical variables associated with titers in Japan. Methods: We enrolled 365 healthcare workers (250 women, 115 men) whose three-month antibody titers were analyzed in our previous study and whose blood samples were collected 183 ± 15 days after the second dose. Participant characteristics, collected previously, were used. The relationships of these factors with antibody titers at six months and percentage changes in antibody titers from three to six months were analyzed. Results: Median age was 44 years. Median antibody titer at six months was 539 U/mL. Older participants had significantly lower antibody titers (20s, 752 U/mL; 60sā€“70s, 365 U/mL). In age-adjusted analysis, smoking was the only factor associated with lower antibody titers. Median percentage change in antibody titers from three to six months was āˆ’29.4%. The only factor significantly associated with the percentage change in Ab titers was not age or smoking, but sex (women, āˆ’31.6%; men, āˆ’25.1%). Conclusion: The most important factors associated with lower antibody titers at six months were age and smoking, as at three months, probably reflecting their effect on peak antibody titers. However, the only factor significantly associated with the attenuation in Ab titers from three to six months was sex, which reduced the sex difference seen during the first three months. Antibody titers may be affected by different factors at different time points.

Details

Language :
English
ISSN :
2076393X
Volume :
9
Issue :
12
Database :
Directory of Open Access Journals
Journal :
Vaccines
Publication Type :
Academic Journal
Accession number :
edsdoj.86d4b0715f426bb74c3f4b8a740aec
Document Type :
article
Full Text :
https://doi.org/10.3390/vaccines9121500