The role of vaccination in preventing HPV-associated malignancies

Prophylactic vaccination against HPV has been publicly funded in Australia since 2007 and three HPV vaccines are currently registered for use (Table 1). Since early 2018, the 9-valent HPV vaccine (Gardasil®9, Seqirus/Merck & Co) has been available on the National Immunisation Program (NIP) for all 9-14 year olds using a two dose schedule. For immunocompromised individuals aged 9-45 years, including people with HIV infection, a three dose schedule is recommended (at 0, 2 and 6 months) (117).

 Table 1.  Prophylactic HPV vaccines registered in Australia

Vaccine

HPV types covered*

Safe for people with HIV infection

Funded by NIP for people with HIV infection

Gardasil®9

6, 11, 16, 18, 31, 33, 45, 52, 58

Yes

9-45 year olds (3 doses)

Gardasil®

6, 11, 16, 18

Yes

N/A

Cervarix®

16, 18

Yes

N/A

*High-risk (oncogenic) HPV types are in bold font

All currently registered HPV vaccines are made using recombinant protein technology to assemble the HPV L1 viral capsid protein into virus-like particles, which are very immunogenic. They are not live vaccines and therefore safe for immunocompromised individuals including people with HIV infection.

While there are no specific data published for Gardasil®9 in HIV-infected individuals, there is ample evidence of immunogenicity of Gardasil® and Cervarix®9 in HIV-infected men (118), women (119, 120), adolescents (121) and children (122). Furthermore, even in HIV-infected individuals, cross-reactive antibodies against non-vaccine HPV types are detected (122-124). The adverse event profile of HPV vaccines is similar to the HIV-uninfected population (mainly injection site pain). There are no adverse effects of HPV vaccines on HIV viral load or CD4+ T cell counts (125, 126).

These vaccines are only effective at preventing initial HPV infection in a type-specific fashion (127). Hence their efficacy is predicated on being administered before an individual has been exposed to a particular HPV type. For people with HIV infection older than 45 years, a potential benefit may still be obtained by vaccination, dependent on their individual risk of future HPV exposure and disease. People with HIV infection may choose to be vaccinated at their own cost, after weighing up the cost versus benefits of vaccination in discussion with a health care provider that understands their individual circumstances (128).