COVID-19 Vaccine Effectiveness in Autumn and Winter 2022 to 2023 Among Older Europeans
Authors: Charlotte Laniece Delaunay, Clara Mazagatos, Iván Martínez-Baz, Gergő Túri, Luise Goerlitz, Lisa Domegan, Adam Meijer, Ana Paula Rodrigues, Noémie Sève, Maja Ilić, Neus Latorre-Margalef, Mihaela Lazar, Marine Maurel, Aryse Melo, Blanca Andreu Ivorra, Itziar Casado, Judit Krisztina Horváth, Silke Buda, Charlene Bennett, Marit de Lange, Raquel Guiomar, Vincent Enouf, Ivan Mlinarić, Tove Samuelsson Hagey, Sorin Dinu, Mercedes Rumayor, Jesús Castilla, Beatrix Oroszi, Ralf Dürrwald, Joan O’Donnell, Mariëtte Hooiveld, Verónica Gomez, Alessandra Falchi, Sanja Kurečić Filipović, Lena Dillner, Rodica Popescu, Sabrina Bacci, Marlena Kaczmarek, Esther Kissling, Virtudes Gallardo García, Esteban Perez Morilla, Irene Pedrosa Corral, Miriam García Vázquez, Ana Milagro-Beamonte, Ana Fernandez Ibañez, Mario Margolles Martins, Jaume Giménez Duran, Bartolomé Sastre Palou, Carla López Causapé, Luis Javier Viloria Raymundo, Tomás Vega Alonso, Ana Ordax Díez, Jose Eugenio Lozano Alonso, Silvia Rojo Bello, Jacobo Mendioroz, Luca Basile, Ana Isabel Martínez Mateo, Carlota Ruiz de Porras, Alba Moya Garcés, Mª Ángeles Marcos, Aurora López Maside, Francesc Botella Quijal, Maite Miralles Espi, Cristina Andreu Salete, María del Carmen García Rodríguez, Juan Antonio Linares, Luis García Comas, Mª Isabel Barranco, María-Dolores Chirlaque, Antonio Moreno Docón, Violeta Ramos Marín, Daniel Castrillejo, Atanasio Gómez Anés, Amparo Larrauro, Gloria Pérez-Gimeno, Marcos Lozano Álvarez, Lorena Vega, Silvia Galindo, Tania Puma, Susana Monge, Francisco Pozo, Inmaculada Casas, Virginia Sandonis, Sonia Vázquez-Morón, Aitziber Echeverría, Camino Trobajo-Sanmartín, Manuel García Cenoz, Guillermo Ezpeleta, Carmen Ezpeleta, Ana Navascués, Katalin Krisztalovics, Krisztina Mucsányiné Juhász, Katalin Kristóf, Ute Preuss, Marianne Wedde, Barbara Biere, Janine Reiche, Djin-Ye Oh, Adele McKenna, Jeff Connell, Michael Joyce, Mariam Bagheri, Sanne Bos, Sharon van den Brink, Frederika Dijkstra, Dirk Eggink, Rianne van Gageldonk-Lafeber, Gabriel Goderski, Chantal Herrebrugh, Liz Jenniskens, Daphne Reukers, John Sluimer, Tara Sprong, Anne Teirlinck, Nienke Veldhijzen, Ruben van der Burgh, Cathrien Kager, Mayra Klinkhamer, Bart Knottnerus, Marloes Riethof, Ruud van den Broek, Safira Wortel, Ausenda Machado, Irina Kislaya, Carlos Aniceto, Licínia Gomes, Nuno Verdasca, Camila Henriques, Daniela Dias, Miguel Lança, Thierry Blanchon, Caroline Guerrisi, Aubane Renard, Titouan Launay, Shirley Masse, Marie Chazelle, Ivana Ferenčak, Bernard Kaić, Vesna Višekruna Vučina, Katica Čusek Adamić, Mirjana Lana Kosanović Ličina, Danijela Lakošeljac, Ivana Mihin Huskić, Diana Nonković, Annasara Carnahan, Eva Hansson-Pihlainen, Elin Arvesen, Nora Nid, Anna-Lena Hansen, Emmi Andersson, Lena Dillner, Adrian Jidovu, Olivia Carmen Timnea, Cătălina Pascu, Mihaela Oprea, Iulia Bistriceanu, Alina Ivanciuc, Maria Elena Mihai
Journal: JAMA Network Open (2024)

Importance In the context of emerging SARS-CoV-2 variants or lineages and new vaccines, it is key to accurately monitor COVID-19 vaccine effectiveness (CVE) to inform vaccination campaigns. Objective To estimate the effectiveness of COVID-19 vaccines administered in autumn and winter 2022 to 2023 against symptomatic SARS-CoV-2 infection (with all circulating viruses and XBB lineage in particular) among people aged 60 years or older in Europe, and to compare different CVE approaches across the exposed and reference groups used. Design, Setting, and Participants This case-control study obtained data from VEBIS (Vaccine Effectiveness, Burden and Impact Studies), a multicenter study that collects COVID-19 and influenza data from 11 European sites: Croatia; France; Germany; Hungary; Ireland; Portugal; the Netherlands; Romania; Spain, national; Spain, Navarre region; and Sweden. Participants were primary care patients aged 60 years or older with acute respiratory infection symptoms who were recruited at the 11 sites after the start of the COVID-19 vaccination campaign from September 2022 to August 2023. Cases and controls were defined as patients with positive and negative, respectively, reverse transcription–polymerase chain reaction (RT-PCR) test results. Exposures The exposure was COVID-19 vaccination. The exposure group consisted of patients who received a COVID-19 vaccine during the autumn and winter 2022 to 2023 vaccination campaign and 14 days or more before symptom onset. Reference group included patients who were not vaccinated during or in the 6 months before the 2022 to 2023 campaign (seasonal CVE), those who were never vaccinated (absolute CVE), and those who were vaccinated with at least the primary series 6 months or more before the campaign (relative CVE). For relative CVE of second boosters, patients receiving their second booster during the campaign were compared with those receiving 1 booster 6 months or more before the campaign. Main Outcomes and Measures The outcome was RT-PCR–confirmed, medically attended, symptomatic SARS-CoV-2 infection. Four CVE estimates were generated: seasonal, absolute, relative, and relative of second boosters. CVE was estimated using logistic regression, adjusting for study site, symptom onset date, age, chronic condition, and sex. Results A total of 9308 primary care patients were included, with 1687 cases (1035 females; median [IQR] age, 71 [65-79] years) and 7621 controls (4619 females [61%]; median [IQR] age, 71 [65-78] years). Within 14 to 89 days after vaccination, seasonal CVE was 29% (95% CI, 14%-42%), absolute CVE was 39% (95% CI, 6%-60%), relative CVE was 31% (95% CI, 15% to 44%), and relative CVE of second boosters was 34% (95% CI, 18%-47%) against all SARS-CoV-2 variants. In the same interval, seasonal CVE was 44% (95% CI, −10% to 75%), absolute CVE was 52% (95% CI, −23% to 82%), relative CVE was 47% (95% CI, −8% to 77%), and relative CVE of second boosters was 46% (95% CI, −13% to 77%) during a period of high XBB circulation. Estimates decreased with time since vaccination, with no protection from 180 days after vaccination. Conclusions and Relevance In this case-control study among older Europeans, all CVE approaches suggested that COVID-19 vaccines administered in autumn and winter 2022 to 2023 offered at least 3 months of protection against symptomatic, medically attended, laboratory-confirmed SARS-CoV-2 infection. The effectiveness of new COVID-19 vaccines against emerging SARS-CoV-2 variants should be continually monitored using CVE seasonal approaches.