Efficacy of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination against SARS-CoV-2 variants of concern: Final analysis of a randomized, placebo-controlled, phase 1b/2 study in South African adults (COV005)
Koen, Anthonet L.; Izu, Alane; Baillie, Vicky; Kwatra, Gaurav; Cutland, Clare L.; Fairlie, Lee; Padayachee, Sherman D.; Dheda, Keertan; Barnabas, Shaun L.; Bhorat, Qasim Ebrahim; Briner, Carmen; Ahmed, Khatija; Bhikha, Sutika; Bhiman, Jinal N.; Du Plessis, Jeanine; Esmail, Aliasgar; Horne, Elizea; Hwa, Shi-Hsia; Oommen-Jose, Aylin; Lambe, Teresa; Laubscher, Matt; Malahleha, Mookho; Benade, Gabriella; McKenzie, Shakeel; Oelofse, Suzette; Patel, Faeezah; Pillay, Sureshnee; Rhead, Sarah; Rodel, Hylton; Taoushanis, Carol; Tegally, Houriiyah; Thombrayil, Asha; Villafana, Tonya L.; Gilbert, Sarah; Pollard, Andrew J.; Madhi, Shabir A.
Date:
2023-05
Abstract:
COVID-19 vaccine efficacy (VE) has been observed to vary against antigenically distinct SARS-CoV-2 variants of concern (VoC). Here we report the final analysis of VE and safety from COV005: a phase 1b/2, multicenter, double-blind, randomized, placebo-controlled study of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination in South African adults aged 18–65 years. South Africa’s first, second, and third waves of SARS-CoV-2 infections were respectively driven by the ancestral SARS-CoV-2 virus (wild type, WT), and SARS-CoV-2 Beta and Delta VoCs. VE against asymptomatic and symptomatic infection was 90.6% for WT, 6.7% for Beta and 77.1% for Delta. No cases of severe COVID-19 were documented ahead of unblinding. Safety was consistent with the interim analysis, with no new safety concerns identified. Notably, South Africa’s Delta wave occurred ≥ 9 months after primary series vaccination, suggesting that primary series AZD1222 vaccination offers a good durability of protection, potentially due to an anamnestic response.
Clinical trial identifier: CT.gov NCT04444674.
Description:
DATA AVAILABILITY : Data will be made available on request.
