Mpox became a global emergency in 2022, disproportionately affecting sexual and gender minorities (SGM), especially men who have sex with men (MSM). This work aims to identify the profile of people who reported prior diagnosis or vaccination against mpox in Brazil.

Cross-sectional online survey with MSM and travestis/trans women (TMW) aged ≥ 18 in Brazil, recruited via social networks (Aug–Dec/2024). We collected sociodemographic and behavioral data, history of mpox and vaccination. We compared characteristics between those reporting mpox diagnosis (yes/no) and vaccination (yes/no).

Among 7,043 participants (MSM: 99%; 18% aged 18–30; 24% with high school or less), 2.2% (n = 152) reported prior mpox diagnosis and 5.1% (n = 358) reported vaccination (1 dose: 46.1%; 2 doses: 47.8%; ≥ 2 doses: 6.1%). Among those diagnosed, 7.9% required hospitalization, 2.4% had no clinical follow-up, 7.9% had sex during infection, and 90.8% reported adherence to isolation. Compared with those not diagnosed, those with mpox diagnosis more often had higher education (84% vs 76%; p = 0.016), self-identified as homosexual (88% vs 81%; p = 0.045), and lived in capitals (88% vs 77%; p = 0.002). They also more frequently reported living with HIV (51% vs 26%; p < 0.001), current PrEP use (66% vs 29%; p < 0.001), ≥ 5 sexual partners in the last six months (71% vs 39%; p < 0.001), chemsex (57% vs 29%; p < 0.001), and recent STI diagnosis (41% vs 14%; p < 0.001). Among vaccinated individuals versus unvaccinated, there were higher proportions aged ≥ 30 (86% vs 82%; p = 0.05), self-identified as White (63% vs 56%; p < 0.001), living with HIV (45% vs 25%; p < 0.001), and current PrEP use (50% vs 29%; p < 0.001). They also more frequently reported ≥ 5 partners in the last six months (51% vs 39%; p < 0.001), chemsex (41% vs 30%; p < 0.001), and recent STI (20% vs 15%; p = 0.03).

Despite mpox’s impact among SGM, vaccination remains low and concentrated in subgroups with higher schooling. Expanding vaccine coverage and improving clinical care are essential, with strategies focused on those at highest risk to reduce vulnerabilities and strengthen Brazil’s mpox response.