학술논문
Immune correlates analysis of a phase 3 trial of the AZD1222 (ChAdOx1 nCoV-19) vaccine
Document Type
article
Author
David Benkeser; Youyi Fong; Holly E. Janes; Elizabeth J. Kelly; Ian Hirsch; Stephanie Sproule; Ann Marie Stanley; Jill Maaske; Tonya Villafana; Christopher R. Houchens; Karen Martins; Lakshmi Jayashankar; Flora Castellino; Victor Ayala; Christos J. Petropoulos; Andrew Leith; Deanne Haugaard; Bill Webb; Yiwen Lu; Chenchen Yu; Bhavesh Borate; Lars W. P. van der Laan; Nima S. Hejazi; Lindsay N. Carpp; April K. Randhawa; Michele P. Andrasik; James G. Kublin; Margaret Brewinski Isaacs; Mamodikoe Makhene; Tina Tong; Merlin L. Robb; Lawrence Corey; Kathleen M. Neuzil; Dean Follmann; Corey Hoffman; Ann R. Falsey; Magdalena Sobieszczyk; Richard A. Koup; Ruben O. Donis; Peter B. Gilbert; on behalf of the AstraZeneca AZD1222 Clinical Study Group; the Immune Assays Team; the United States Government (USG)/CoVPN Biostatistics Team
Source
npj Vaccines, Vol 8, Iss 1, Pp 1-13 (2023)
Subject
Language
English
ISSN
2059-0105
Abstract
Abstract In the phase 3 trial of the AZD1222 (ChAdOx1 nCoV-19) vaccine conducted in the U.S., Chile, and Peru, anti-spike binding IgG concentration (spike IgG) and pseudovirus 50% neutralizing antibody titer (nAb ID50) measured four weeks after two doses were assessed as correlates of risk and protection against PCR-confirmed symptomatic SARS-CoV-2 infection (COVID-19). These analyses of SARS-CoV-2 negative participants were based on case-cohort sampling of vaccine recipients (33 COVID-19 cases by 4 months post dose two, 463 non-cases). The adjusted hazard ratio of COVID-19 was 0.32 (95% CI: 0.14, 0.76) per 10-fold increase in spike IgG concentration and 0.28 (0.10, 0.77) per 10-fold increase in nAb ID50 titer. At nAb ID50 below the limit of detection (< 2.612 IU50/ml), 10, 100, and 270 IU50/ml, vaccine efficacy was −5.8% (−651%, 75.6%), 64.9% (56.4%, 86.9%), 90.0% (55.8%, 97.6%) and 94.2% (69.4%, 99.1%). These findings provide further evidence towards defining an immune marker correlate of protection to help guide regulatory/approval decisions for COVID-19 vaccines.