Department of Medicine and Technological Innovation, University of Insubria, ASST Sette Laghi, 21100 Varese, Italy.
Research Centre in Epidemiology and Preventive Medicine (EPIMED), Department of Medicine and Surgery, University of Insubria, 21100 Varese, Italy.
Int J Mol Sci. 2023 Sep 6;24(18):13728. doi: 10.3390/ijms241813728.
Although the safety and efficacy of COVID-19 vaccines in older people are critical to their success, little is known about their immunogenicity among elderly residents of long-term care facilities (LTCFs). A single-center prospective cohort study was conducted: a total IgG antibody titer, neutralizing antibodies against Wild-type, Delta Plus, and Omicron BA.2 variants and T cell response, were measured eight months after the second dose of BNT162b2 vaccine (T0) and at least 15 days after the booster (T1). Forty-nine LTCF residents, with a median age of 84.8 ± 10.6 years, were enrolled. Previous COVID-19 infection was documented in 42.9% of the subjects one year before T0. At T1, the IgG titers increased up to 10-fold. This ratio was lower in the subjects with previous COVID-19 infection. At T1, IgG levels were similar in both groups. The neutralizing activity against Omicron BA.2 was significantly lower (65%) than that measured against Wild-type and Delta Plus (90%). A significant increase of T cell-specific immune response was observed after the booster. Frailty, older age, sex, cognitive impairment, and comorbidities did not affect antibody titers or T cell response. In the elderly sample analyzed, the BNT162b2 mRNA COVID-19 vaccine produced immunogenicity regardless of frailty.
尽管 COVID-19 疫苗在老年人中的安全性和有效性对其成功至关重要，但对于长期护理机构（LTCF）中老年人的免疫原性知之甚少。进行了一项单中心前瞻性队列研究：在第二次 BNT162b2 疫苗接种后 8 个月（T0）和至少在加强针后 15 天（T1）测量总 IgG 抗体滴度、针对野生型、Delta Plus 和 Omicron BA.2 变体的中和抗体和 T 细胞反应。共纳入了 49 名中位年龄为 84.8 ± 10.6 岁的 LTCF 居民。在 T0 前一年，有 42.9%的受试者有既往 COVID-19 感染史。在 T1 时，IgG 滴度增加了 10 倍。在有既往 COVID-19 感染的受试者中，该比例较低。在 T1 时，两组的 IgG 水平相似。针对 Omicron BA.2 的中和活性明显较低（65%），而针对野生型和 Delta Plus 的中和活性分别为 90%。在加强针后观察到 T 细胞特异性免疫反应显著增加。虚弱、年龄较大、性别、认知障碍和合并症不会影响抗体滴度或 T 细胞反应。在分析的老年样本中，BNT162b2 mRNA COVID-19 疫苗产生了免疫原性，无论虚弱程度如何。
