Vaccine adherence to vaccination schedule among male HIV-positive patients: a single-center study

BACKGROUND: The study centre collaborated with the public health service to recover the vaccinations missed during the COVID-19 pandemic. Vaccinations against pneumococcus (PCV/PPV), human papillomavirus (HPV9) and herpes zoster (HZric) have been offered to people living with HIV/AIDS (PLWHA) in care at the clinic. This study aims to estimate vaccine adherence in men with HIV/AIDS to the proposed vaccination schedule. MATERIALS AND METHODS: In this retrospective observational study, data were extracted from the regional platform of vaccinations, including 941 males LWHA in care in 2022. Chi-squared tests were performed to assess differences in adherence according to the risk of transmission and nationality. RESULTS: The mean age was 52.97 years (SD = 13.1). Italian patients were 88.6%. Regarding the risk of HIV transmission, 828 (88%) men who have sex with men (MSM) and 113 (12%) heterosexual men (ETX) were included. About anti-SARS-CoV-2 (COV), 884 patients (93.94%) completed the primary cycle, 793 (84.27%) received the 3rd dose, 335 (35.6%) the 4th dose, 120 (12.75%) the 5th dose. The complete vaccination course was carried out by 488 patients (51.86%) for PCP/PPV, 487 (51.75%) for MenACWY, 485 (51.54%) for MenB, 277 (29.44%) for anti-Haemophilus Influenzae, 303 (32.2%) for HPV9, 286 (30.39%) for HZric and 427 (45.38%) for anti-Tetanus and Diphtheria. The adherence to the 3rd and 4th doses of COV, HPV9 and HZ2 vaccines was higher for MSM than ETX (p < 0.05). Italian patients had higher adherence to the 4th dose of the COV and MENACWY vaccines than the foreigners (p < 0.05). CONCLUSIONS: Overall, adherence to the vaccination programme was low, except for the COV vaccine. This study provides an overview of vaccination coverage. It lays the groundwork for a more in-depth analysis to identify determinants of vaccine adherence among PLWHA, which will be further investigated by the studies of the INF-ACT project, aiming to assess all determinants of vaccine hesitancy. KEY MESSAGES: • Monitoring adherence to the vaccination schedule is crucial in order to detect critical issues early and take intervention. • The finding of low vaccination adherence in our study alerts us to the possible risks of low vaccination coverage, particularly in a fragile population such as people living with HIV/AIDS.