Effectiveness of mRNA vaccine boosters against infection with the SARS-CoV-2 omicron (B.1.1.529) variant in Spain: a nationwide cohort study. Issue 9 (September 2022)

• Record Type: Journal Article
• Authors: Monge, Susana; Rojas-Benedicto, Ayelén; Olmedo, Carmen; Mazagatos, Clara; José Sierra, María; Limia, Aurora; Martín-Merino, Elisa; Larrauri, Amparo; Hernán, Miguel A; Moreno, David; Méndez Díaz, Manuel; Huerta González, Ismael; Galmés Truyols, Antònia; Barreno Estévez, Ana; García Velasco, Valvanuz; Rodríguez Recio, Mª Jesús; Sacristán, José; Martínez Marcos, Montserrat; Pastor Villalba, Eliseo; Macías Ortiz, María José; García Vallejo, Ana; Sánchez Gómez, Amaya; García Pina, Rocío; Barricarte Gurea, Aurelio; Sancho Martínez, Rosa; Ochoa, Eva María; Vázquez Cantero, Mauricio; Gómez Anés, Atanasio; Pareja Megía, María Jesús; Castán, Yolanda; Fonseca Álvarez, Manuel Roberto; Salvà Fiol, Antonia; Sánchez Janáriz, Hilda; López Arce, Luz; Cisneros Martín, María Ángeles; Gibernau, Frederic Jose; Fernandez Buey, Cesar; Villatoro Bongiorno, Katja; Rubio García, Francisco Javier; Santos Guerra, Fernando; Astray Mochales, Jenaro; Francisco Verdu, Francisco Javier; García Romero, Isabel; Oriza Bernal, Rosa; Gómez Pérez, Tomás; Hijano Villegas, Salomé; Román Soto, Sergio; Gómez-Barroso, Diana; Lapeña, María Fé; Yagüe Galaup, Virgilio; Alfaro Latorre, Mercedes; Aguilera Guzmán, Marta; Crespo Sánchez-Eznarriaga, Belén; Neira León, Montserrat; Cívicos Villa, Noemí;
• Is Part Of: Lancet infectious diseases. Volume 22:Issue 9(2022)
• Page Start: 1313
• Page End: 1320
• Publication Date: 2022-09
• Subjects: Communicable diseases -- Periodicals; Infection -- Periodicals; Communicable Diseases -- Periodicals; Infection -- Periodicals; Maladies infectieuses -- Périodiques; Infection -- Périodiques; Communicable diseases; Infection; Periodicals; 616.905
• DOI: 10.1016/S1473-3099(22)00292-4
• Languages: English
• ISSNs: 1473-3099

Abstract

Summary: Background: The omicron (B.1.1.529) variant of SARS-CoV-2 has increased capacity to elude immunity and cause breakthrough infections. The aim of this study was to estimate the effectiveness of mRNA-based vaccine boosters (third dose) against infection with the omicron variant by age, sex, time since complete vaccination, type of primary vaccine, and type of booster. Methods: In this nationwide cohort study, we linked data from three nationwide population registries in Spain (Vaccination Registry, Laboratory Results Registry, and National Health System registry) to select community-dwelling individuals aged 40 years or older, who completed their primary vaccine schedule at least 3 months before the start of follow-up, and had not tested positive for SARS-CoV-2 since the start of the pandemic. On each day between Jan 3, and Feb 6, 2022, we matched individuals who received a booster mRNA vaccine and controls of the same sex, age group, postal code, type of vaccine, time since primary vaccination, and number of previous tests. We estimated risk of laboratory-confirmed SARS-CoV-2 infection using the Kaplan-Meier method and compared groups using risk ratios (RR) and risk differences. Vaccine effectiveness was calculated as one minus RR. Findings: Between Jan 3, and Feb 6, 2022, 3 111 159 matched pairs were included in our study. Overall, the estimated effectiveness from day 7 to 34 after a booster was 51·3% (95% CI 50·2–52·4). Estimated effectiveness was 52·5% (51·3–53·7) for an mRNA-1273 booster and 46·2% (43·5–48·7) for a BNT162b2 booster. Effectiveness was 58·6% (55·5–61·6) if primary vaccination had been with ChAdOx1 nCoV-19 (Oxford–AstraZeneca), 55·3% (52·3–58·2) with mRNA-1273 (Moderna), 49·7% (48·3–51·1) with BNT162b2 (Pfizer–BioNTech), and 48·0% (42·5–53·7) with Ad26.COV2.S (Janssen). Estimated effectiveness was 43·6% (40·0–47·1) when the booster was administered between 151 days and 180 days after complete vaccination and 52·2% (51·0–53·3) if administered more than 180 days after primary scheduled completion. Interpretation: Booster mRNA vaccine-doses were moderately effective in preventing infection with the omicron variant of SARS-CoV-2 for over a month after administration, which indicates their suitability as a strategy to limit the health effects of COVID-19 in periods of omicron variant domination. Estimated effectiveness was higher for mRNA-1273 compared with BNT162b2 and increased with time between completed primary vaccination and booster. Funding: None.