Background: This study aimed to assess the safety and immunogenicity of MVC-COV1901, a recombinant COVID-19 protein vaccine, containing S-2P protein adjuvanted with CpG 1018 and aluminum hydroxide, for people living with HIV (PWH). Methods: A total of 57 PWH of ≥20 years of age who are on stable antiretroviral therapy were compared with 882 HIV-negative participants. Participants received two doses of MVC-COV1901 28 days apart. Results: No vaccine-related serious adverse events (SAEs) were recorded. Seroconversion rates (SCRs) of 100% and 99.8% were achieved in PWH and comparators, respectively, 28 days after the second dose. After adjusting for sex, age, BMI category, and comorbidity, the adjusted GMT ratio of comparator/PWH was 3.2 (95% CI 2.5–4). A higher CD4/CD8 ratio was associated with a higher GMT (R = 0.27, p = 0.039). MVC-COV1901 has shown robust safety but elicited weaker immune responses in PWH. Conclusions: Further investigations may be needed to determine whether PWH require distinct immunization strategies with improved immunogenicity. The main study is registered at ClinicalTrials.gov (NCT04695652).
