ABSTRACT
The objectives of this study were to assess the dynamics of the SARS-CoV-2 anti-RBD-IgG response over time among older people after COVID-19 infection or vaccination and its comparison with indicative levels of protection. Geriatric patients with SARS-CoV-2 serological test results were included and divided into three groups. A vaccine group (n = 34), a group of natural COVID-19 infection (n = 32), and a group who contracted COVID-19 less than 15 days after the first injection (n = 17). Eighty-three patients were included; the median age with IQR was 87 (81-91) years. In the vaccine group at 1 month since the first vaccination, the median titer of anti-RBD-IgG was 620 (217-1874) BAU/ml with 87% of patients above the theoretical protective threshold of 141 BAU/ml according to Dimeglio et al. (J Infec. 84(2):248-88, [7]). Seven months after the first vaccination, this titer decreased to 30 (19-58) BAU/ml with 9.5% of patients > 141 BAU/ml. In the natural COVID-19 infection group, at 1 month since the date of first symptom onset, the median titer was 798 (325-1320) BAU/ml with 86.7% of patients > 141 BAU/ml and fell to 88 (37-385) with 42.9% of patients > 141 BAU/ml at 2 months. The natural infection group was vaccinated 3 months after the infection. Five months after the vaccination cycle, the median titer was 2048 (471-4386) BAU/ml with 83.3% of patients > 141 BAU/ml. This supports the clinical results describing the decrease in vaccine protection over time and suggests that vaccination after infection can maintain significantly higher antibody titer levels for a prolonged period of time.
Subject(s)
COVID-19 , Vaccines , Aged , Aged, 80 and over , BNT162 Vaccine , COVID-19/prevention & control , Humans , Immunity, Humoral , Immunoglobulin G , SARS-CoV-2ABSTRACT
COVID-19 is a particularly aggressive disease for the elderly as 86% of deaths related to COVID-19 occur in people over 65 years of age. Despite the urgent need for a preventive treatment, there are currently no serious leads, other than the vaccination. The aim of this retrospective case-control study is to find a pharmacological preventive treatment of COVID-19 in elderly patients. One-hundred-seventy-nine patients had been in contact with other COVID-19 patients at home or in hospital, of whom 89 had tested RT-PCR-positive (COVID-pos) for the virus and 90 had tested RT-PCR-negative (COVID-neg). Treatments within 15 days prior to RT-PCR (including antihypertensive drugs, antipsychotics, antibiotics, nonsteroidal anti-inflammatory drugs, proton pump inhibitors (PPIs), oral antidiabetics (OADs), corticosteroids, immunosuppressants), comorbidities, symptoms, laboratory values, and clinical outcome were all collected. COVID-pos patients more frequently had a history of diabetes (P = .016) and alcoholism (P = .023), a lower leukocyte count (P = .014) and a higher mortality rate - 29.2% versus 14.4% - (P = .014) when compared to COVID-neg patients. Patients on PPIs were 2.3 times less likely (odds ratio [OR] = 0.4381, 95% confidence interval [CI] [0.2331, 0.8175], P = .0053) to develop COVID-19 infection, compared to those not on PPIs. No other treatment decreased or increased this risk. COVID-pos patients on antipsychotics (P = .0013) and OADs (P = .0153), particularly metformin (P = .0237), were less likely to die. Thus, patients on treatment with PPI were less likely to develop COVID-19 infection, and those on antipsychotics or metformin had a lower risk of mortality. However, prospective studies, including clinical trials, are needed to confirm or not these findings.