Uptake of Influenza, Pneumococcal, and COVID-19 Vaccines Among People Living with HIV: Findings from the Ontario HIV Treatment Network Cohort Study.

People living with HIV are at higher risk of severe illness due to common respiratory pathogens. We estimated uptake of influenza, pneumococcal, and COVID-19 vaccines among people engaged in HIV care in Ontario, Canada, and identified factors associated with vaccine uptake. We conducted a cross-sectional analysis of interviewer-administered, annual questionnaires (2021-2023) linked to medical charts and laboratory data. We used modified Poisson regression to calculate adjusted prevalence ratios and 95% confidence intervals for self-reported uptake of influenza (yes vs. no, last year), pneumococcal (≥ 1 vs. 0 doses, lifetime), and COVID-19 (≥ 2 vs. 0 - 1 doses and ≥ 3 vs. 2 doses, lifetime) vaccines. Among 3,163 people with HIV (median age = 54 years; 78% men; 98% on antiviral treatment), overall uptake was 70% (95%CI = 68.5% - 72.1%) for influenza, 72.7% (95%CI = 70.8% - 74.7%) for pneumococcal, and 89% (95%CI = 88.0% - 90.3%) for ≥ 2 doses COVID-19 vaccines. Among two-dose COVID-19 vaccine recipients, uptake of ≥ 3 doses was 84.9% (95%CI = 83.4% - 86.5%). Across all three vaccines, uptake was significantly associated with older age, identifying as a sexual minority man, higher education, difficulty paying for housing costs, food insecurity, being a former or non-smoker, abstaining from alcohol or recreational drugs, having greater social support, certain comorbidities, entering HIV care earlier in time, and having well-managed HIV. Despite generally high coverage, vaccine uptake remains below national targets in people living with HIV in Ontario, particularly for those at highest risk of severe respiratory infections. Interventions that address predisposing, enabling, and need factors associated with vaccine uptake may help improve access and promote vaccine confidence in this population.