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

Joseph Makhema; Emily Shava; Alane Izu; Tendani Gaolathe; Lesego Kuate; Adam Walker; Lucy Carty; Panayiotis Georgiou; Coulson Kgathi; Wonderful T Choga; Tumalano Sekoto; Ngozana Seonyatseng; Tuelo Mogashoa; Comfort N Maphorisa; Terence Mohammed; Tshenolo Ntalabgwe; Tshepho T Frank; Boitumelo Matlhaku; Ame Diphoko; Thandie Phindela; Agripa Kaunda; Poloko Kgari; Thomas Kanyakula; Gape Palalani; Isabella Phakedi; Mompati Mmalane; Sylvia Taylor; Sikhulile Moyo

doi:10.1016/j.ijregi.2023.11.002

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

IJID Reg. 2023 Nov 10:10:35-43. doi: 10.1016/j.ijregi.2023.11.002. eCollection 2024 Mar.

Authors

Joseph Makhema^{1

2}, Emily Shava¹, Alane Izu^{3

4}, Tendani Gaolathe^{1

5}, Lesego Kuate⁶, Adam Walker⁷, Lucy Carty⁸, Panayiotis Georgiou⁹, Coulson Kgathi¹, Wonderful T Choga^{1

10}, Tumalano Sekoto¹, Ngozana Seonyatseng¹, Tuelo Mogashoa¹, Comfort N Maphorisa¹, Terence Mohammed¹, Tshenolo Ntalabgwe¹, Tshepho T Frank¹, Boitumelo Matlhaku¹, Ame Diphoko¹, Thandie Phindela¹, Agripa Kaunda¹, Poloko Kgari¹, Thomas Kanyakula¹, Gape Palalani¹, Isabella Phakedi¹, Mompati Mmalane¹, Sylvia Taylor¹¹, Sikhulile Moyo^{1

2

10

12

13}

Affiliations

¹ Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana.
² Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, USA.
³ South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
⁴ Department of Science and Innovation, National Research Foundation South African Research Initiative in Vaccine Preventable Diseases Unit, University of the Witwatersrand, Johannesburg, South Africa.
⁵ Faculty of Medicine, University of Botswana, Gaborone, Botswana.
⁶ Department of Health Systems Management, Clinical Services, Ministry of Health Botswana, Gaborone, Botswana.
⁷ Medical Evidence, Vaccine and Immune Therapies, BioPharmaceuticals Medicine, AstraZeneca, Cambridge, UK.
⁸ Medical and Payer Evidence Statistics, BioPharmaceuticals Medicine, AstraZeneca, Cambridge, UK.
⁹ Late Development, Vaccines and Immune Therapies, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK.
¹⁰ School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana.
¹¹ Infection Evidence Strategy, Vaccine and Immune Therapies, BioPharmaceuticals Medical, AstraZeneca, Cambridge, UK.
¹² School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
¹³ Division of Medical Virology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Abstract

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.

Keywords: AZD 1222; Antibody responses; AstraZeneca; Botswana; COVID-19 vaccination.

Abstract

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