Safety of AZD1222 COVID-19 vaccine and low Incidence of SARS-CoV-2 infection in Botswana following ChAdOx1(AZD1222) vaccination : a single-arm open-label interventional study – final study results

SUPPLEMENTARY FIGURE S1: Binding antibody responses to SARS-CoV-2 spike (Anti-S) following vaccination with ChAdOx1 (AZD1222).SUPPLEMENTARY FIGURE S2: SAR-COV-2 variant Dynamics (Fig S2-A) and cumulative number of cases by COVID-19 zones (showing study sites 1 to 5).SUPPLEMENTARY TABLE S1: Line listing of adverse events of special interest.SUPPLEMENTARY TABLE S2: Line listing of serious adverse events.SUPPLEMENTARY TABLE S3: Incidence (per 1,000 participant-years) of AE, localised and systemic adverse events by prior COVID infection status.SUPPLEMENTARY TABLE S4: Sociodemographic characteristics of participants enrolled in the immunogenicity subcohort of the ChAdOx1(AZD1222) study.SUPPLEMENTARY TABLE S5: geometric mean concentrations of Anti-Nucleocapsid antibody levels by dose and time (days) since first-dose.SUPPLEMENTARY TABLE S6: geometric mean concentrations of Anti-Spike antibody levels by dose and time (days) since first-dose.OBJECTIVES : We report the final analysis of the single-arm open-label study evaluating the safety and COVID-19 incidence after AZD1222 vaccination in Botswana conducted between September 2021 and August 2022. METHODS : The study included three groups of adults (>18 years), homologous AZD1222 primary series and booster (AZ2), heterologous primary series with one dose AZD1222, and AZD1222 booster (HPS), and primary series other than AZD1222 and AZD1222 booster (OPS). We compared the incidence of AEs in participants with and without prior COVID-19 infection using an exact test for rate ratios. RESULTS : Among 10,894 participants, 9192 (84.4%) were enrolled at first vaccine dose, 521 (4.8%) at second vaccine, and 1181 (10.8%) at the booster vaccine. Of 10,855 included in the full analysis set, 1700 received one dose of AZD1222; 5377 received two doses; 98 received a heterologous series including one AZD1222 and a booster; 30 in the HPS group; 1058 in the OPS group; and 2592 in the AZ2 group. No laboratory-confirmed COVID-19 hospitalizations or deaths were reported. The incidence of laboratory-confirmed symptomatic COVID infection for the AZ2 group was 6.22 (95% confidence interval: 2.51-12.78) per 1000 participant-years (1000-PY) and 3.5 (95% confidence interval: 0.42-12.57) per 1000-PY for AZ2+booster group. Most adverse events were mild, with higher incidence in participants with prior COVID-19 infection. Individuals with prior COVID-19 exposure exhibited higher binding antibody responses. No differences in outcomes were observed by HIV status. CONCLUSION : AZD1222 is safe, effective, and immunogenic for people living with and without HIV.AstraZeneca under an externally sponsored collaborative research agreement, partially supported through the Sub-Saharan African Network for TB/HIV Research Excellence (SANTHE 2.0), by the Bill and Melinda Gates Foundation (INV-033558) and the National Institutes of Health NIH Fogarty International Center.http://www.elsevier.com/locate/ijregihj2024School of Health Systems and Public Health (SHSPH)SDG-03:Good heatlh and well-bein