Meyers Eline, De Rop Liselore, Engels Fien, Gioveni Claudia, Coen Anja, De Burghgraeve Tine, Digregorio Marina, Van Ngoc Pauline, De Clercq Nele, Buret Laëtitia, Coenen Samuel, Deschepper Ellen, Padalko Elizaveta, Callens Steven, Duysburgh Els, De Sutter An, Scholtes Beatrice, Verbakel Jan Y, Heytens Stefan, Cools Piet
Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, 9000 Ghent, Belgium.
EPI-Centre, Department of Public Health and Primary Care, KU Leuven, 3000 Leuven, Belgium.
Vaccines (Basel). 2024 Aug 22;12(8):951. doi: 10.3390/vaccines12080951.
When COVID-19 vaccines were implemented, nursing home residents (NHRs) and staff (NHS) in Belgium were prioritized for vaccination. To characterize the vaccine response over time in this population and to identify poorly responding groups, we assessed antibody concentrations two (T1), four (T2) and six months (T3) after primary course BNT162b2 vaccination in six groups of infection-naive/infection-primed NHRs/NHS, with/without comorbidity (NHRs only). Participant groups (N = 125 per group) were defined within a national serosurveillance study in nursing homes, based on questionnaire data. Dried blood spots were analyzed using ELISA for the quantification of SARS-CoV-2 S1RBD IgG antibodies. Among all groups, antibody concentrations significantly decreased between T1 and T2/T3, all with a ≥70% decrease at T3, except for infection-primed staff (-32%). Antibody concentrations among infection-naive NHRs were 11.96 times lower than those among infection-primed NHR, while the latter were comparable (x1.05) to infection-primed NHS. The largest proportion [13% (95% CI: 11-24%)] of vaccine non-responders was observed in the group of infection-naive NHRs with comorbidities. A longer interval between infection and vaccination (≥3 months) elicited higher antibody responses. Our data retrospectively show the necessity of timely COVID-19 booster vaccination. Infection-naive NHRs require special attention regarding immune monitoring in future epidemics or pandemics.
在新冠病毒疾病（COVID-19）疫苗开始接种时，比利时的养老院居民（NHRs）和工作人员（NHS）被列为优先接种对象。为了描述该人群随时间推移的疫苗反应特征，并识别反应不佳的群体，我们在六组未感染/曾感染过的NHRs/NHS（仅NHRs有合并症）中，评估了BNT162b2初次接种后两个月（T1）、四个月（T2）和六个月（T3）时的抗体浓度。根据问卷调查数据，在一项全国养老院血清监测研究中定义了参与者组（每组N = 125）。使用酶联免疫吸附测定（ELISA）分析干血斑，以定量严重急性呼吸综合征冠状病毒2（SARS-CoV-2）刺突蛋白受体结合域（S1RBD）IgG抗体。在所有组中，T1与T2/T3之间抗体浓度显著下降，除曾感染过的工作人员（下降32%）外，所有组在T3时均下降≥70%。未感染的NHRs中的抗体浓度比曾感染过的NHRs低11.96倍，而后者与曾感染过的NHS相当（为其1.05倍）。在患有合并症的未感染NHRs组中，观察到疫苗无反应者的比例最高[13%（95%置信区间：11 - 24%）]。感染与接种之间的间隔时间较长（≥3个月）会引发更高的抗体反应。我们的数据回顾性地表明了及时接种COVID-19加强针的必要性。在未来的流行病或大流行中，未感染的NHRs在免疫监测方面需要特别关注。
