ABSTRACT
Introduction The third dose of the COVID-19 vaccine is especially necessary in people over 65 years of age due to their lower immune response. Methods We designed a multicentre, prospective observational study including 98 people ≤65 years old who lived in two nursing homes in Valladolid, Spain. One of the groups had previous experience with SARS-CoV-2 (n=68;69.4%) and the other was naïve (n=30;30.6%). We evaluated the response to the three doses of the Comirnaty vaccine and the dynamics of antibodies during 5 consecutive serum samplings: 2 after the first two doses of vaccination, one three months after the first dose, another at 6 months and the last one month after the third dose. IgG antibodies against SARS-CoV-2 S1, RBD and N antigens were analysed. Results Both groups increased the level of Abs against S1 and RBD, but the experienced group showed a 130-fold higher humoral response due to hybrid immunisation (infection+vaccination). The response to vaccination with Comirnaty against COVID-19 was higher in those ≤65 years with previous experience than those who were naïve. However, the amount of antibodies against S1 and RBD equalised at 6 months. After the third dose, both groups raised the amount of antibodies to a similar level. The reinfections suggested by the analysis of antibodies against N were frequent in both groups. Discussion The third dose showed a clear benefit for elderly people, with the reinforcement of the antibody levels after the decline suffered after six months of the first two doses.
ABSTRACT
Introduction: The third dose of the COVID-19 vaccine is especially necessary in people over 65 years of age due to their lower immune response. Methods: We designed a multicentre, prospective observational study including 98 people ≤65 years old who lived in two nursing homes in Valladolid, Spain. One of the groups had previous experience with SARS-CoV-2 (n=68;69.4%) and the other was naïve (n=30;30.6%). We evaluated the response to the three doses of the Comirnaty vaccine and the dynamics of antibodies during 5 consecutive serum samplings: 2 after the first two doses of vaccination, one three months after the first dose, another at 6 months and the last one month after the third dose. IgG antibodies against SARS-CoV-2 S1, RBD and N antigens were analysed. Results: Both groups increased the level of Abs against S1 and RBD, but the experienced group showed a 130-fold higher humoral response due to hybrid immunisation (infection+vaccination). The response to vaccination with Comirnaty against COVID-19 was higher in those ≤65 years with previous experience than those who were naïve. However, the amount of antibodies against S1 and RBD equalised at 6 months. After the third dose, both groups raised the amount of antibodies to a similar level. The reinfections suggested by the analysis of antibodies against N were frequent in both groups. Discussion: The third dose showed a clear benefit for elderly people, with the reinforcement of the antibody levels after the decline suffered after six months of the first two doses.
Subject(s)
COVID-19 , SARS-CoV-2 , Aged , Humans , BNT162 Vaccine , COVID-19 Vaccines , Immunoglobulin GABSTRACT
In Spain, the 2021/22 influenza season overlapped with the sixth wave of the 2019 coronavirus disease pandemic (COVID-19). Influenza is a major public health problem associated with high morbidity and mortality. The objectives of this study were to determine the knowledge, perceptions and practices of influenza vaccination in the Spanish population, coinciding with the COVID-19 pandemic, with special attention paid to people over 65 years of age. A cross-sectional study was carried out by conducting 2211 telephone interviews. It was observed that 81.6% of people ≥ 65 years were vaccinated annually or with some frequency compared to 35.5% of those under 65 years (p < 0.001). Fifty percent of Spaniards showed an intention to be vaccinated in the 2021/22 campaign, during the SARS-CoV2 pandemic. In the case of people ≥ 65 years old, this figure was 83% compared to 42% of those under 65 years old (p < 0.001). Significant predictors of intention to be vaccinated were age of 65 years or older (OR 1.8, 95% CI 1.3-2.5), female sex (OR 1.9, 95% CI 1.5-2.4), belonging to risk groups (OR 2.2, 95% CI 1.6-3.1) and having been previously vaccinated (OR 29.7, 95% CI 22.5-39.2). The main reasons for deciding to be vaccinated were the need to be protected against the virus and to be vaccinated annually. On the other hand, lack of recommendation and considering the influenza vaccine as not necessary were the main reasons for not getting vaccinated. In addition, health personnel stood out as the main source of information (32.9%) compared to traditional media (26.9%) and public administration (12.3%). This study aimed to assess and analyse the factors influencing willingness to receive influenza vaccines in the COVID-19 era among Spanish adults, as well as the main information channels and strategies to encourage vaccination.