Protection against COVID-19 hospitalisation conferred by primary-series vaccination with AZD1222 in non-boosted individuals: first vaccine effectiveness results of the European COVIDRIVE study and meta-regression analysis

• Published in: The Lancet regional health. Europe Vol. 31; p. 100675
• Main Authors: Meeraus, Wilhelmine, de Munter, Leonie, Gray, Christen M., Dwivedi, Akshat, Wyndham-Thomas, Chloé, Ouwens, Mario, Hartig-Merkel, Wendy, Drikite, Laura, Rebry, Griet, Carmona, Antonio, Stuurman, Anke L., Chi Nguyen, Thi Yen, Mena, Guillermo, Mira-Iglesias, Ainara, Icardi, Giancarlo, Otero-Romero, Susana, Baumgartner, Sebastian, Martin, Charlotte, Taylor, Sylvia, Bollaerts, Kaatje
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2023; Elsevier
• Subjects: AZD1222; COVID-19; COVIDRIVE; Durability; European; Hospitalisation; Internal Medicine; Meta-regression; Public Health; Vaccine effectiveness; COVID-19; Meta-regression; AZD1222; Vaccine effectiveness; Durability; European; COVIDRIVE; Hospitalisation
• ISSN: 2666-7762; 2666-7762
• DOI: 10.1016/j.lanepe.2023.100675

Vaccine effectiveness (VE) studies with long-term follow-up are needed to understand durability of protection against severe COVID-19 outcomes conferred by primary-series vaccination in individuals not receiving boosters. COVIDRIVE is a European public-private partnership evaluating brand-specific vaccine effectiveness (VE). We report a prespecified interim analysis of primary-series AZD1222 (ChAdOx1 nCoV-19) VE. Seven Study Contributors in Europe collected data on individuals aged ≥18 years who were hospitalised with severe acute respiratory infection (June 1st, 2021–September 5th, 2022) and eligible for COVID-19 vaccination prior to hospitalisation. In this test-negative case–control study, individuals were defined as test-positive cases or test-negative controls (SARS-CoV-2 RT-PCR) and were either fully vaccinated (two AZD1222 doses, 4–12 weeks apart, completed ≥14 days prior to symptom onset; no booster doses) or unvaccinated (no COVID-19 vaccine prior to hospitalisation). The primary objective was to estimate AZD1222 VE against COVID-19 hospitalisation. A literature review and meta-regression were conducted to contextualise findings on durability of protection. 761 individuals were included during the 15-month analysis period. Overall AZD1222 VE estimate was 72.8% (95% CI, 53.4–84.1). VE was 93.8% (48.6–99.3) in participants who received second AZD1222 doses ≤8 weeks prior to hospitalisation, with spline-based VE estimates demonstrating protection (VE ≥ 50%) 30 weeks post-second dose. Meta-regression analysis (data from seven publications) showed consistent results, with ≥80% protection against COVID-19 hospitalisation through ∼43 weeks post-second dose, with some degree of waning. Primary-series AZD1222 vaccination confers protection against COVID-19 hospitalisation with enduring levels of VE through ≥6 months. AstraZeneca.