1. Homologous or heterologous administration of mRNA or adenovirus-vectored vaccines show comparable immunogenicity and effectiveness against the SARS-CoV-2 Omicron variant.
- Author
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Pastore G, Polvere J, Fiorino F, Lucchesi S, Montesi G, Rancan I, Zirpoli S, Lippi A, Durante M, Fabbiani M, Tumbarello M, Montagnani F, Medaglini D, and Ciabattini A
- Subjects
- Humans, SARS-CoV-2, BNT162 Vaccine, COVID-19 Vaccines, Vaccination, 2019-nCoV Vaccine mRNA-1273, Pandemics, RNA, Messenger, Adenoviridae, Antibodies, Viral, Antibodies, Neutralizing, COVID-19 prevention & control, Vaccines
- Abstract
Background: Heterologous prime-boost schedules have been employed in SARS-CoV-2 vaccination, yet additional data on immunogenicity and effectiveness are still needed., Research Design and Methods: Here, we measured the immunogenicity and effectiveness in the real-world setting of the mRNA booster dose in 181 subjects who had completed primary vaccination with ChAdOx1, BNT162b2, or mRNA1273 vaccines (IMMUNO_COV study; protocol code 18,869). The spike-specific antibody and B cell responses were analyzed up to 6 months after boosting., Results: After an initial slower antibody response, the heterologous ChAdOx1/mRNA prime-boost formulation elicited spike-specific IgG titers comparable to homologous approaches, while spike-specific B cells showed a higher percentage of CD21
- CD27- atypical cells compared to homologous mRNA vaccination. Mixed combinations of BNT162b2 and mRNA-1273 elicited an immune response comparable with homologous strategies. Non-significant differences in the Relative Risk of infection, calculated over a period of 18 months after boosting, were reported among homologous or heterologous vaccination groups, indicating a comparable relative vaccine effectiveness., Conclusions: Our data endorse the heterologous booster vaccination with mRNA as a valuable alternative to homologous schedules. This approach can serve as a solution in instances of formulation shortages and contribute to enhancing vaccine strategies for potential epidemics or pandemics.- Published
- 2024
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