Covid-19 and Influenza Vaccination Among Adults Stably Engaged in HIV Care

Abstract

Introduction. Vaccination against COVID-19 and influenza is recommended for individuals living with HIV. However, data on real-world uptake remain incomplete, particularly among populations facing socioeconomic barriers. We evaluated vaccination uptake and associated factors at an urban HIV outpatient centre serving a socioeconomically disadvantaged area. COVID-19 vaccination was initially offered at the centre to facilitate access, whereas influenza vaccination was only available externally.Methods. We analysed a random 50% sample of 750 adults attending the outpatient service. Vaccination records were obtained from the national registry; demographic and clinical data were retrieved from medical records. Logistic regression identified factors associated with vaccine uptake.  Results. Between December 2020 and July 2024, 333/375 (88.8%) individuals started COVID-19 vaccination, typically receiving two mRNA vaccine doses 3-4 weeks apart, and 286/375 (76.3%) completed full vaccination with the recommended additional dose. The odds of full vaccination were reduced among participants aged <50 years and heterosexual men and women (vs. men who have sex with men). Other associated factors were a migrant background, injecting drug use, history of advanced immunosuppression, HIV viraemia, and CD4 counts <500 cells/mm3. Influenza vaccination uptake (2022/2023 season) was low (99/375, 26.4%), although nearly 4-fold higher among those vaccinated against COVID-19.Conclusions. Our findings highlight disparities in COVID-19 vaccine coverage and the suboptimal uptake of influenza vaccination among adults stably engaged with HIV care.  Sustained efforts are needed to address barriers to vaccination, particularly among individuals with additional vulnerabilities. Integrating vaccination into HIV care may improve uptake and reduce preventable illness in this population.

Note:
Funding declaration: GA and DZ were funded through a speciality training fellowship.

Conflict of Interests: LS: personal fees from Angelini, Gilead, GSK, MSD, Pfizer, and ViiV, and research funding from Gilead and GSK for unrelated work. MI: personal fees from Biogen Italia, MICOM, and Roche, and research funding from BD Biosciences, Gilead, GSK and Roche for unrelated work. AMG: personal fees from Abbott, Gilead, GSK, MSD, Roche, and ViiV, and research funding from Gilead, Roche and ViiV for unrelated work. The remaining authors have no competing interests to declare.

Ethical Approval: The study was approved by the Ethics Committee of Fondazione PTV, University of Rome Tor Vergata (registration number 47.24).

Keywords: COVID-19, Influenza, mRNA vaccine, HIV, Uptake, CD4 count