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

Wilhelmine Meeraus; Leonie de Munter; Christen M Gray; Akshat Dwivedi; Chloé Wyndham-Thomas; Mario Ouwens; Wendy Hartig-Merkel; Laura Drikite; Griet Rebry; Antonio Carmona; Anke L Stuurman; Thi Yen Chi Nguyen; Guillermo Mena; Ainara Mira-Iglesias; Giancarlo Icardi; Susana Otero-Romero; Sebastian Baumgartner; Charlotte Martin; Sylvia Taylor; Kaatje Bollaerts

doi:10.1016/j.lanepe.2023.100675

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

Lancet Reg Health Eur. 2023 Jul 1:31:100675. doi: 10.1016/j.lanepe.2023.100675. eCollection 2023 Aug.

Authors

Wilhelmine Meeraus¹, Leonie de Munter², Christen M Gray³, Akshat Dwivedi², Chloé Wyndham-Thomas², Mario Ouwens⁴, Wendy Hartig-Merkel², Laura Drikite², Griet Rebry², Antonio Carmona^{5

6}, Anke L Stuurman^{1

2}, Thi Yen Chi Nguyen^{1

2}, Guillermo Mena^{7

8

9}, Ainara Mira-Iglesias^{5

6}, Giancarlo Icardi^{10

11}, Susana Otero-Romero¹², Sebastian Baumgartner¹³, Charlotte Martin¹⁴, Sylvia Taylor¹, Kaatje Bollaerts²

Affiliations

¹ Medical Evidence, Vaccines & Immune Therapies, AstraZeneca, Cambridge, UK.
² P95 Pharmacovigilance and Epidemiology, Leuven, Belgium.
³ Real World Science, BioPharmaceuticals Medical, AstraZeneca, Cambridge, UK.
⁴ Medical and Payor Statistics, BioPharmaceutical Business Unit, AstraZeneca, Mölndal, Sweden.
⁵ Vaccine Research Department, Fundación para el Fomento de la Investigación Sanitaria y Biomédica (FISABIO) de la Comunitat Valenciana, Salud Pública, Valencia, Spain.
⁶ Biomedical Research Consortium of Epidemiology and Public Health (CIBER-ESP), Instituto de Salud Carlos III, Madrid, Spain.
⁷ Preventive Medicine Department - Germans Trias i Pujol University Hospital, Badalona, Spain.
⁸ Autonomous University of Barcelona, Bellaterra, Spain.
⁹ Germans Trias I Pujol Research Institute (IGTP), Badalona, Spain.
¹⁰ Interuniversity Research Centre on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy.
¹¹ Department of Health Sciences, University of Genoa, Italy.
¹² Servicio de Medicina Preventiva y Epidemiología, Hospital Universitari Vall d'Hebron, Vall d'Hebron Barcelona Campus Hospitalari, Barcelona, Spain.
¹³ Fourth Medical Department with Infectious Diseases and Tropical Medicine, Klinik Favoriten/Kaiser-Franz-Josef Hospital, Vienna, Austria.
¹⁴ Infectious Diseases Department, Centre Hospitalier Universitaire Saint-Pierre, Brussels, Belgium.

Abstract

Background: 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.

Methods: 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.

Findings: 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.

Interpretation: Primary-series AZD1222 vaccination confers protection against COVID-19 hospitalisation with enduring levels of VE through ≥6 months.

Funding: AstraZeneca.

Keywords: AZD1222; COVID-19; COVIDRIVE; Durability; European; Hospitalisation; Meta-regression; Vaccine effectiveness.