Department of Radiation Health Management, Fukushima Medical University School of Medicine, Fukushima City, Fukushima, 960-1247, Japan.
Department of Internal Medicine, Hirata Central Hospital, Hirata Village, Fukushima, 963-8202, Japan.
Sci Rep. 2022 Nov 7;12(1):18929. doi: 10.1038/s41598-022-21797-x.
To reveal waning humoral immunity after second dose BNT162b2 vaccinations in a rural Japanese community and determine factors affecting antibody titers. We aimed to report Immunoglobulin G (IgG) antibody against the SARS-CoV-2 spike (S1) protein levels and neutralizing activity in a large scale community based cohort.
Participants in the observational cross-sectional study received a second dose of vaccination with BNT162b2 (Pfizer/BioNTech) and were not previously infected with COVID-19. Questionnaire-collected data on sex, age, adverse vaccine reactions, and medical history was obtained.
Data from 2496 participants revealed that older age groups reached a low antibody titer 90-120 days after the second vaccination. Neutralizing activity decreased with age; 35 (13.3%) of those aged ≥ 80 years had neutralizing activity under the cut-off value. Neutralizing activity > 179 days from the second vaccination was 11.6% compared to that at < 60 days from the second vaccination. Significantly lower IgG antibody titers and neutralizing activity were associated with age, male sex, increased time from second vaccination, smoking, steroids, immunosuppression, and comorbidities.
Antibody titer decreased substantially over time. Susceptible populations, older people, men, smokers, steroid users, immunosuppression users, and people with three or more comorbidities may require a special protection strategy.
在日本农村社区揭示第二剂 BNT162b2 疫苗接种后体液免疫的衰减情况，并确定影响抗体滴度的因素。我们旨在报告基于大规模社区的队列中针对 SARS-CoV-2 刺突（S1）蛋白的 IgG 抗体和中和活性。
在这项观察性横断面研究中，参与者接受了第二剂 BNT162b2（辉瑞/生物科技）疫苗接种，且之前未感染过 COVID-19。通过问卷调查收集了性别、年龄、疫苗不良反应和病史等数据。
来自 2496 名参与者的数据显示，年龄较大的群体在第二次接种后 90-120 天达到低抗体滴度。中和活性随年龄下降；80 岁及以上的人群中有 35 人（13.3%）的中和活性低于临界值。与第二次接种后 60 天内相比，第二次接种后 179 天以上的中和活性为 11.6%。年龄、男性、第二次接种后时间增加、吸烟、类固醇、免疫抑制和合并症与 IgG 抗体滴度和中和活性显著降低相关。
抗体滴度随时间显著下降。易感染人群、老年人、男性、吸烟者、类固醇使用者、免疫抑制剂使用者以及有三种或更多合并症的人群可能需要特殊的保护策略。
