High efficacy of HPV vaccine in HIV positive gay men
Simon Collins, HIV i-Base
An open label phase 2 HPV vaccination study in the US reported high efficacy at preventing both low- and high-grade squamous interepithelial lesions (LSIL/HSIL) in HIV positive gay men aged 18 to 26.
The study, reported by Joel Palefsky and colleagues in CID.
Of the 260 men screened at 17 clinic sites, 88/260 (34%) were excluded due to existing HSIL, and 144 were vaccinated with the quadrivalent HPV vaccine (qHPV) active against HPV 6, 11, 16 and 18. Of these, 74% had LSIL at baseline and 77% were either seropositive or DNA positive to at least one strain: 72%, 50%, 45% and 33% to 6, 11, 16 and 18, respectively.
Median age was 23, 60% were African-American and 34% were white; 91% had had at least one sexual partner in the previous 6 months. Median CD4 counts was 594 cells/mm3 (range: 237 to 150) and 91% had viral load <400 copies/mL.
Cytology, high-resolution anoscopy with biopsies of lesions, serology, and HPV testing of the mouth/penis/scrotum/anus/perianus, were performed at screening and months 7, 12 and 24.
No lesions were detected in people naive to each clade, compared to 11.1, 2.2, 4.5, and 2.8 cases/100 person-years in those previously exposed to clades 6, 11, 16 and 18 respectively.
Antibody responses were also not affected by current or nadir CD4 count or by viral load (other than lower titres to HPV18 in those with high viral load at month 7.
This is the first study to report such high prevalence of HSIL in HIV positive young gay men that also tracked incidence of lesions by subtype.
Given the elevated risks of HPV-related cancers in gay men and that this is increased further by HIV infection, these results support broader vaccination for this population. Ideally, this should be at a target age of 11/12 before the risk of sexual exposure to HPV or in catch-up programmes afterwards. In the UK this included making the vaccine available to gay men up to 45 years old.
Palefsky JM et al. High prevalence of anal high-grade squamous intraepithelial lesions, and prevention through human papillomavirus vaccination, in young men who have sex with men living with HIV. Clinical Infectious Diseases, ciab434. DOI: 10.1093/cid/ciab434. (15 May 2021).