HPV vaccine

• human papilloma virus (HPV) virus-like particles (VLP) can be produced via the synthesis and self-assembly of the major virus capsid protein
  • these HPV L1 VLPs exhibit morphological and antigenic properties that are virtually identical to native virons - these properties have been utilized in the development of HPV L1 VLP subunit vaccines
  • at present, data reveals that all women receiving the HPV vaccine have seroconverted - because of this there are no immune correlates which denote protection
    • note though that the anti-VLP antibody responses in VLP-immunized women are markedly greater than that identified in natural infections

In the UK:

HPV vaccine recommendations

Routine adolescent and universal programme

Children who become eligible for the HPV vaccine from the academic year 2023 to 2024 (date of birth between 1 September 2010 to 31 August 2011) onwards will only require one dose and this will continue to be routinely offered to children in school year 8 and those of an equivalent age who are not in mainstream education.

For those children who became eligible for the HPV vaccination programme in the 2022 to 2023 academic year (date of birth between 1 September 2009 to 31 August 2010) the following applies:

1. Those who started their HPV vaccination schedule and have already received one dose of the vaccine will be considered fully vaccinated.
2. Those who have not yet received any HPV vaccinations will be eligible to receive one dose of the HPV vaccine.

All other cohorts who require catch-up via their school aged immunisation services (SAIS) provider or general practice will move to a one dose schedule from 1 September 2023, and remain eligible until their 25th birthday.

In summary:

men who have sex with men (MSM) programme

Eligible MSM aged less than 25 years will move to a one dose HPV schedule from 1 September 2023. MSM who have already received at least one dose of the HPV vaccine before their 25th birthday can be considered to have completed their vaccination course and do not require further doses.

MSM aged 25 years and older (up to and including 45 years) should continue on the 2 dose HPV vaccination schedule.

In summary:

Immunosuppressed cohort

Eligible individuals who are known to be immunosuppressed at the time of vaccination and those who are living with HIV, including those on antiretroviral therapy, should continue to be offered a 3 dose schedule.

Notes:

• HPV is a double-stranded DNA virus that infects the surface of the skin and mucosae of the upper respiratory and anogenital tracts
  • are over 100 types of HPV viruses of which about 40 infect the genital tract
    • classified as being either high risk or low risk depending upon their association with the development of cancer
      • Types 16 and 18 are high risk and types 6 and 11 are low risk
      • Types 16 and 18 account for around 80% of all cervical cancers, the remaining 20% are due to 11 other high-risk HPV types
        • the proportion of cancers of the anus, penis, mouth and throat, vagina and vulva which are related to a high-risk HPV infection (and which are caused by types 16 and 18) vary by cancer site
      • majority of HPV infections do not cause any symptoms and infection is usually cleared by the body's own immune system without the need for other treatment
        • 70% of new high risk infections will clear within a year
        • 90% of new infections clear within 2 years
      • persistent infection with high risk HPV types such as types 16 and 18 can cause cell changes leading to lesions, warts or ano-genital cancers. These include cancer of the cervix, vulva or vagina in women, cancer of the penis in men and some cancers of the head, neck, throat or anus in either sex. Other types of HPV such as 6 and 11 cause genital warts which is the most commonly-diagnosed viral sexually-transmitted infection in the UK
  • Transmission of HPV
    • HPV infections are spread primarily by sexual contact with an infected partner, particularly through sexual intercourse but also by non-penetrative genital contact, including oral sex
    • HPV is one of the most commonly transmitted sexually-transmitted infections in the UK and anyone who is sexually active can contract it. The risk of acquiring infection increases with the number of previous sexual partners, the introduction of a new sexual partner, and the sexual history of partners
    • Infection commonly occurs soon after sexual debut and almost 40% of women are infected within two years (5)
      
      
  • Reduction of cervical cancer risk
    • cear evidence from both randomized trials and population based studies shows that vaccination against human papillomavirus reduces the incidence of cervical pre-cancer (8)
      • these data suggest that the vaccine reduces the incidence of cervical cancer

Reference:

• (1) Harper DM et al.ustained efficacy up to 4.5 years of a bivalent L1 virus-like particle vaccine against human papillomavirus types 16 and 18: follow-up from randomised control trial. Lancet 2006;367:1247-1255
• (2) Future II Study Group. Quadrivalent vaccine against human papillomavirus to prevent high-grade cervical lesions. N Engl J Med. 2007 May 10;356(19):1915-27.
• (3) Future II Study Group. Effect of prophylactic human papillomavirus L1 virus-like-particle vaccine on risk of cervical intraepithelial neoplasia grade 2, grade 3, and adenocarcinoma in situ: a combined analysis of four randomised clinical trials.Lancet. 2007 Jun 2;369(9576):1861
• (4) Tint Tint Wai and Dilip Patil. Modern management of abnormal cervical smear. BJMP 2008; 1(2).
• (5) DOH (UK). The 'Green Book' chapter on Human papillomavirus (HPV) - accessed 24/7/19
• (6) Public Health England (PHE). Vaccine update: issue 296, July 2019, HPV special edition
• (7) UK Health Security Agency (June 2023).HPV vaccination programme: changes from September 2023 letter
• (8) Rahangdale L et al. Human papillomavirus vaccination and cervical cancer risk BMJ 2022; 379 :e070115