EFFECTIVENESS of COVID-19 VACCINATION among PEOPLE LIVING with HIV during AN OUTBREAK

ABSTRACT

Background: A large-scale community COVID-19 outbreak occurred between April and August 2021 in Taiwan, where non-pharmaceutical interventions (NPIs) have been strictly implemented and COVID-19 vaccination program was not implemented until 1 March, 2021. Although COVID-19 vaccination is recommended for at-risk populations, the vaccine effectiveness in people living with HIV (PLWH) remains incompletely understood. We evaluated the effectiveness of COVID-19 vaccination among PLWH during a COVID-19 outbreak in Taiwan. Methods: From 1 March to 30 September, 2021, all adult PLWH without previous SARS-CoV-2 infection were included and advised to receive 2 doses of COVID-19 vaccine. The government-funded vaccination campaign provided different types of COVID-19 vaccine, including ChAdOx1 nCoV-19 (AZD1222), BNT162b2 (Pfizer-BioNTech), mRNA-1273 (Moderna), and MVC-COV1901 (Medigen) vaccines. The primary endpoint of this study was the vaccine effectiveness in preventing COVID-19 among PLWH, which was estimated by comparing incidence rates between the unvaccinated, partially vaccinated, and fully vaccinated groups in a dynamic cohort. Results: During the study period, 3131 PLWH were included, with 99.9% on antiretroviral therapy, 99.8% being MSM and median CD4 count of 627 cells/mm3. In the dynamic cohort, 3128 PLWH contributed 516892 person-days of follow-up (PDFU) to the unvaccinated group, 2476 PLWH contributed 139163 PDFU to the partially vaccinated group, and 236 PLWH contributed 12011 PDFU to the fully vaccinated group (Table). During the follow-up, 37 PLWH (1.2%) acquired SARS-CoV-2 infections. The incidence rate of SARS-CoV-2 infection was 6.4 per 100,000 PDFU in the unvaccinated group, which decreased to 2.9 and 0 per 100,000 PDFU in the partially and fully vaccinated groups, respectively. The adjusted incidence rate ratios were 0.47 (95% CI, 0.17-1.32) in the partially vaccinated group and <0.01 in the fully vaccinated group compared with the unvaccinated group, resulting in vaccine effectiveness rates of 53.4% and 99.9% for single-and 2-dose COVID-19 vaccination, respectively. Conclusion: COVID-19 vaccination was clinically effective among PLWH during the outbreak setting where NPIs were strictly implemented.