Determinants of Anti-S Immune Response at 9 Months after COVID-19 Vaccination in a Multicentric European Cohort of Healthcare Workers—ORCHESTRA Project

• Published in: Viruses Vol. 14; no. 12; p. 2657
• Main Authors: Collatuzzo, Giulia, Lodi, Vittorio, Feola, Daniela, De Palma, Giuseppe, Sansone, Emanuele, Sala, Emma, Janke, Christian, Castelletti, Noemi, Porru, Stefano, Spiteri, Gianluca, Monaco, Maria Grazia Lourdes, Larese Filon, Francesca, Negro, Corrado, Cegolon, Luca, Beresova, Jana, Fabianova, Eleonora, Carrasco-Ribelles, Lucia A., Toràn-Monserrat, Pere, Rodriguez-Suarez, Marta Maria, Fernandez-Tardon, Guillermo, Asafo, Shuffield S., Ditano, Giorgia, Abedini, Mahsa, Boffetta, Paolo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 28.11.2022; MDPI
• Subjects: Analysis; Antibodies; Antibodies, Viral; antibody level; confidence interval; Coronaviruses; COVID-19; COVID-19 - prevention & control; COVID-19 infection; COVID-19 Vaccines; Female; females; Germany; Health aspects; Health Personnel; health services; Humans; Immune response; Immunity; immunization; Immunoassay; Infections; Italy; Medical personnel; meta-analysis; Public health; Regression analysis; Risk assessment; Romania; Serology; Severe acute respiratory syndrome coronavirus 2; Slovakia; Sociodemographics; Spain; standard deviation; temporal trends; Vaccination; vaccine; vaccines; Spain; Italy; Romania; Slovakia; Germany; COVID-19; antibody level; vaccine; temporal trends; immunization; serology
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v14122657

Background: The persistence of antibody levels after COVID-19 vaccination has public health relevance. We analyzed the determinants of quantitative serology at 9 months after vaccination in a multicenter cohort. Methods: We analyzed data on anti-SARS-CoV-2 spike antibody levels at 9 months from the first dose of vaccinated HCW from eight centers in Italy, Germany, Spain, Romania and Slovakia. Serological levels were log-transformed to account for the skewness of the distribution and normalized by dividing them by center-specific standard errors. We fitted center-specific multivariate regression models to estimate the cohort-specific relative risks (RR) of an increase of one standard deviation of log antibody level and the corresponding 95% confidence interval (CI), and combined them in random-effects meta-analyses. Finally, we conducted a trend analysis of 1 to 7 months’ serology within one cohort. Results: We included 20,216 HCW with up to two vaccine doses and showed that high antibody levels were associated with female sex (p = 0.01), age (RR = 0.87, 95% CI = 0.86–0.88 per 10-year increase), 10-day increase in time since last vaccine (RR = 0.97, 95% CI 0.97–0.98), previous infection (3.03, 95% CI = 2.92–3.13), two vaccine doses (RR = 1.22, 95% CI = 1.09–1.36), use of Spikevax (OR = 1.51, 95% CI = 1.39–1.64), Vaxzevria (OR = 0.57, 95% CI = 0.44–0.73) or heterologous vaccination (OR = 1.33, 95% CI = 1.12–1.57), compared to Comirnaty. The trend in the Bologna cohort, based on 3979 measurements, showed a decrease in mean standardized antibody level from 8.17 to 7.06 (1–7 months, p for trend 0.005). Conclusions: Our findings corroborate current knowledge on the determinants of COVID-19 vaccine-induced immunity and declining trend with time.