Exploring mpox vaccination uptake and tolerability among people living with HIV: A study in an infectious disease unit in Italy

Background A live attenuated non-replicating vaccine (MVA-BN) is approved for immunization against mpox. We provide an overview of the uptake and tolerability of mpox vaccination among people living with HIV (PLWH) in a single centre in Italy and draw comparisons to individuals without HIV.Methods We retrospectively collected clinical data of people vaccinated with MVA-BN in a tertiary-level hospital in Florence, Italy. Baseline data were collected from pre-vaccination screening questionnaires; adverse events data were collected before the second dose through another dedicated questionnaire.Results We vaccinated 332 subjects. Of them, 36.1% (n = 120) were PLWH, with higher median age, higher rate of previous smallpox vaccination and a higher proportion of transgender individuals compared to people without HIV. As for vaccine tolerability, subcutaneous administration was associated with significantly fewer adverse events than intradermal. There were no significant differences in tolerability between PLWH and individuals without HIV. Among people who did not complete the vaccine cycle, migrant and sex worker populations were disproportionately represented.Conclusion Our experience suggests that mpox vaccination has been accepted and well-tolerated in individuals with and without HIV. More work is needed to conduct immunization campaigns in marginalized populations such as migrants and sex workers.