Relative effectiveness of bivalent Original/Omicron BA.4-5 mRNA vaccine in preventing severe COVID-19 in persons 60 years and above during SARS-CoV-2 Omicron XBB.1.5 and other XBB sublineages circulation, Italy, April to June 2023

Fabiani, M.; Mateo-Urdiales, A.; Sacco, C.; Rota, M. C.; Fotakis, E. A.; Petrone, D.; Del Manso, M.; Siddu, A.; Stefanelli, P.; Bella, A.; Riccardo, F.; Rezza, G.; Palamara, A. T.; Brusaferro, S.; Pezzotti, P.

doi:10.2807/1560-7917.ES.2023.28.32.2300397

During predominant circulation of SARS-CoV-2 Omicron XBB.1.5 and other XBB sublineages (April-June 2023), we found that a second or third booster of Comirnaty bivalent Original/Omicron BA.4-5 mRNA vaccine, versus a first booster received at least 120 days earlier, was effective in preventing severe COVID-19 for more than 6 months post-administration in persons 60 years and above. In view of autumn 2023 vaccination campaigns, use of bivalent Original/Omicron BA.4-5 mRNA vaccines might be warranted until monovalent COVID-19 vaccines targeting Omicron XBB.1 sublineages become available.

Relative effectiveness of bivalent Original/Omicron BA.4-5 mRNA vaccine in preventing severe COVID-19 in persons 60 years and above during SARS-CoV-2 Omicron XBB.1.5 and other XBB sublineages circulation, Italy, April to June 2023 / Fabiani, M.; Mateo-Urdiales, A.; Sacco, C.; Rota, M. C.; Fotakis, E. A.; Petrone, D.; Del Manso, M.; Siddu, A.; Stefanelli, P.; Bella, A.; Riccardo, F.; Rezza, G.; Palamara, A. T.; Brusaferro, S.; Pezzotti, P.. - In: EUROSURVEILLANCE. - ISSN 1025-496X. - 28:32(2023). [10.2807/1560-7917.ES.2023.28.32.2300397]