AUTHOR=Fedele Giorgio , Trentini Filippo , Schiavoni Ilaria , Abrignani Sergio , Antonelli Guido , Baldo Vincenzo , Baldovin Tatjana , Bandera Alessandra , Bonura Filippa , Clerici Pierangelo , De Paschale Massimo , Fortunato Francesca , Gori Andrea , Grifantini Renata , Icardi Giancarlo , Lazzarotto Tiziana , Lodi Vittorio , Mastroianni Claudio Maria , Orsi Andrea , Prato Rosa , Restivo Vincenzo , Carsetti Rita , Piano Mortari Eva , Leone Pasqualina , Olivetta Eleonora , Fiore Stefano , Di Martino Angela , Brusaferro Silvio , Merler Stefano , Palamara Anna Teresa , Stefanelli Paola TITLE=Evaluation of humoral and cellular response to four vaccines against COVID-19 in different age groups: A longitudinal study JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.1021396 DOI=10.3389/fimmu.2022.1021396 ISSN=1664-3224 ABSTRACT=

To date there has been limited head-to-head evaluation of immune responses to different types of COVID-19 vaccines. A real-world population-based longitudinal study was designed with the aim to define the magnitude and duration of immunity induced by each of four different COVID-19 vaccines available in Italy at the time of this study. Overall, 2497 individuals were enrolled at time of their first vaccination (T0). Vaccine-specific antibody responses induced over time by Comirnaty, Spikevax, Vaxzevria, Janssen Ad26.COV2.S and heterologous vaccination were compared up to six months after immunization. On a subset of Comirnaty vaccinees, serology data were correlated with the ability to neutralize a reference SARS-CoV-2 B strain, as well as Delta AY.4 and Omicron BA.1. The frequency of SARS-CoV-2-specific CD4+ T cells, CD8+ T cells, and memory B cells induced by the four different vaccines was assessed six months after the immunization. We found that mRNA vaccines are stronger inducer of anti-Spike IgG and B-memory cell responses. Humoral immune responses are lower in frail elderly subjects. Neutralization of the Delta AY.4 and Omicron BA.1 variants is severely impaired, especially in older individuals. Most vaccinees display a vaccine-specific T-cell memory six months after the vaccination. By describing the immunological response during the first phase of COVID-19 vaccination campaign in different cohorts and considering several aspects of the immunological response, this study allowed to collect key information that could facilitate the implementation of effective prevention and control measures against SARS-CoV-2.