Effectiveness of mRNA vaccines and waning of protection against SARS-CoV-2 infection and severe covid-19 during predominant circulation of the delta variant in Italy: retrospective cohort study.
Massimo FabianiMaria PuopoloCristina MorcianoMatteo SpuriStefania Spila AlegianiAntonietta FiliaFortunato D'AnconaMartina Del MansoFlavia RiccardoMarco TallonValeria ProiettiChiara SaccoMarco MassariRoberto Da CasAlberto Mateo-UrdialesAndrea SidduSerena BattilomoAntonino BellaAnna Teresa PalamaraPatrizia PopoliSilvio BrusaferroGiovanni RezzaFrancesca Menniti IppolitoPatrizio Pezzottinull nullPublished in: BMJ (Clinical research ed.) (2022)
The results support the vaccination campaigns targeting high risk people, those aged ≥60 years, and healthcare workers to receive a booster dose of vaccine six months after the primary vaccination cycle. The results also suggest that timing the booster dose earlier than six months after the primary vaccination cycle and extending the offer of the booster dose to the wider eligible population might be warranted.