No abstract

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

The aim of this study was to assess the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines among people living with HIV (PLWH) with severe immunosuppression, after a booster dose. The design was a case-control study nested in a prospective cohort of PLWH. All patients with CD4 cell count <200 cells/mm 3 who had received additional dose of messenger RNA (mRNA) COVID-19 vaccine, after a standard immunization scheme were included. Control group: patients age-and sex-matched, with CD4 ≥ 200 cells/mm 3 , in the ratio of 2:1. Antibody response to a booster dose (anti-S levels 33.8 ≥ BAU/mL) and neutralizing activity against SARS-CoV-2 B.1, B.1.617.2, and Omicron BA.1, BA.2, and BA.5 strains were assessed after the booster shot. Fifty-four PLWH were included, 18 with CD4 counts < 200 cells/mm 3 . Fifty-one (94%) showed response to a booster dose. Response was less frequent in PLWH with CD4 < 200 cells/mm 3 than in those with CD4 counts ≥ 200 cells/mm 3 (15 [83%] vs. 36 [100%], p = 0.033). In the multivariate analysis, CD4 counts ≥ 200 cells/mm 3 [incidence rate ratio (IRR) = 18.1 (95% confidence interval [CI]: 16.8-19.5), p < 0.001] was associated with a higher probability of showing antibody response. Neutralization activity against SARS-CoV-2 B.1, B.1.617, BA.1, and BA.2 strains was significantly inferior among individuals with CD4 counts < 200 cells/mm 3 . In conclusion, among PLWH with CD4 counts < 200 cells/mm 3 , the immune response elicited by mRNA additional vaccine dose is reduced.