Lai Alessia, Caimi Barbara, Franzetti Marco, Bergna Annalisa, Velleca Rossella, Gatti Antonella, Rossi Pier Luigi, D'Orso Marco, Pregliasco Fabrizio, Balotta Claudia, Calicchio Giuseppe
Department of Biomedical and Clinical Sciences L. Sacco, University of Milan, 20157 Milan, Italy.
Azienda Servizi alla Persona, Istituti Milanesi Martinitt e Stelline e Pio Albergo Trivulzio, 20146 Milan, Italy.
Vaccines (Basel). 2022 Mar 14;10(3):446. doi: 10.3390/vaccines10030446.
Residents of long-term care facilities (LTCFs) have been dramatically hit by the COVID-19 pandemic on a global scale as older age and comorbidities pose an increased risk of severe disease and death. The aim of the study was to assess the quantity and durability of specific antibody responses to SARS-CoV-2 after the first cycle (two doses) of BNT162b2 vaccine. To achieve this, SARS-CoV-2 Spike-specific IgG (S-IgG) titers was evaluated in 432 residents of the largest Italian LTCF at months 2 and 6 after vaccination. By stratifying levels of humoral responses as high, medium, low and null, we did not find any difference when comparing the two time points; however, the median levels of antibodies halved overtime. As positive nucleocapsid serology was associated with a reduced risk of a suboptimal response at both time points, we conducted separate analyses accordingly. In subjects with positive serology, the median level of anti-S IgG slightly increased at the second time point, while a significant reduction was observed in patients without previous exposure to the virus. At month 6, diabetes alone was associated with an increased risk of impaired response. Our data provide additional insights into the longitudinal dynamics of the immune response to BNT162b2 vaccination in the elderly, highlighting the need for SARS-CoV-2 antibody monitoring following third-dose administration.
长期护理机构（LTCFs）的居民在全球范围内受到了新冠疫情的巨大冲击，因为老年人和合并症会增加患重病和死亡的风险。本研究的目的是评估BNT162b2疫苗第一周期（两剂）接种后对SARS-CoV-2的特异性抗体反应的数量和持久性。为实现这一目标，在接种疫苗后的第2个月和第6个月，对意大利最大的长期护理机构的432名居民的SARS-CoV-2刺突特异性IgG（S-IgG）滴度进行了评估。通过将体液反应水平分为高、中、低和无反应，我们在比较两个时间点时未发现任何差异；然而，抗体的中位数水平随时间减半。由于阳性核衣壳血清学与两个时间点次优反应风险降低相关，我们相应地进行了单独分析。在血清学阳性的受试者中，第二次时间点抗S IgG的中位数水平略有增加，而在未接触过该病毒的患者中观察到显著降低。在第6个月，仅糖尿病与反应受损风险增加相关。我们的数据为老年人对BNT162b2疫苗免疫反应的纵向动态提供了更多见解，强调了在接种第三剂后进行SARS-CoV-2抗体监测的必要性。
