Vaccine effectiveness against COVID-19 hospitalisation in adults (≥ 20 years) during Alpha- and Delta-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021

• Authors: ANGELA MC Rose; NICOLAY Nathalie; MARTIN Virginia Sandonis; MAZAGATOS Clara; PETROVIC Goranka; NIESSEN F Annabel; MACHADO Ausenda; LAUNAY Odile; DENAYER Sarah; SEYLER Lucie; BARUCH Joaquin; BURGUI Cristina; LOGHIN Isabela I; DOMEGAN Lisa; VAIKUTYTE Roberta; HUSA Petr; PANAGIOTAKOPOULOS George; AOUALI Nassera; DUERRWALD Ralf; HOWARD Jennifer; POZO Francisco; SASTRE-PALOU Bartolome; NONKOVIC Diana; KNOL Mirjam J; KISLAYA Irina; NGUYEN Liem Binh Luong; BOSSUYT Nathalie; DEMUYSER Thomas; DZIUGYTE Ausra; MARTINEZ-BAZ Ivan; POPESCU Corneliu; DUFFY Roisin; KULIESE Monika; SOUČKOVÁ Lenka; MICHELAKI Stella; SIMON Marc; REICHE Janine; OTERO-BARROS Maria Teresa; MAKARIC Zvjezdana Lovric; BRUIJNING-VERHAGEN Patricia C J L; GOMEZ Veronica; LESIEUR Zineb; BARBEZANGE Cyril; ELS Van Nedervelde; BORG Maria-Louise; CASTILLA Jesus; LAZAR Mihaela; DONNELL Joan; JONIKAITE Indre; DEMLOVÁ Regina; AMERALI Marina; WIRTZ Gil; TOLKSDORF Kristin; VALENCIANO Marta; BACCI Sabrina; KISSLING Esther
• Year of publication: 2023
• Type: Article in Periodical
• Magazine / Source: EUROSURVEILLANCE
• MU Faculty or unit: Faculty of Medicine
• Web: https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2023.28.47.2300186
• Doi: http://dx.doi.org/10.2807/1560-7917.ES.2023.28.47.2300186
• Keywords: Alpha; Delta; Europe; hospital; SARS-CoV-2; vaccine effectiveness
• Description: IntroductionTwo large multicentre European hospital networks have estimated vaccine effectiveness (VE) against COVID-19 since 2021.AimWe aimed to measure VE against PCR-confirmed SARS-CoV-2 in hospitalised severe acute respiratory illness (SARI) patients >= 20 years, combining data from these networks during Alpha (March-June)- and Delta (June-December)-dominant periods, 2021.MethodsForty-six participating hospitals across 14 countries follow a similar generic protocol using the test-negative case-control design. We defined complete primary series vaccination (PSV) as two doses of a two-dose or one of a single-dose vaccine >= 14 days before onset.ResultsWe included 1,087 cases (538 controls) and 1,669 cases (1,442 controls) in the Alpha- and Delta-dominant periods, respectively. During the Alpha period, VE against hospitalisation with SARS-CoV2 for complete Comirnaty PSV was 85% (95% CI: 69-92) overall and 75% (95% CI: 42-90) in those aged >= 80 years. During the Delta period, among SARI patients >= 20 years with symptom onset >= 150 days from last PSV dose, VE for complete Comirnaty PSV was 54% (95% CI: 18-74). Among those receiving Comirnaty PSV and mRNA booster (any product) >= 150 days after last PSV dose, VE was 91% (95% CI: 57-98). In time-since-vaccination analysis, complete all-product PSV VE was > 90% in those with their last dose < 90 days before onset; >= 70% in those 90-179 days before onset.ConclusionsOur results from this EU multi-country hospital setting showed that VE for complete PSV alone was higher in the Alpha- than the Delta-dominant period, and addition of a first booster dose during the latter period increased VE to over 90%.