Relative effectiveness of monovalent and bivalent mRNA boosters in preventing severe COVID-19 due to omicron BA.5 infection up to 4 months post-administration in people aged 60 years or older in Italy: a retrospective matched cohort study

https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(23)00374-2/fulltext?dgcid=hubspot_update_feature_updatealerts_laninf&utm_campaign=update-laninf&utm_medium=email&_hsmi=285459858&_hsenc=p2ANqtz-8UdROygUXmUhi61y9R1KWzDTVQFTrX_K37k38W4gJRSREjbJOu5Ee-FMRGQxloiiWFPIecdP7lN2_pDK-2ouqmIBy_1g&utm_content=285449430&utm_source=hs_email