HPV Vaccination of Girls to Help Prevent Cervical Cancer
The Department of Health has recently announced a routine HPV immunisation programme for girls aged 12 to 13. Nerys Hairon explores some of the issues
Keywords: HPV Vaccination, Cervical Cancer, women’s health, screening, immunisation
Hairon, N. (2007) HPV Vaccination of Girls to Help Prevent Cervical Cancer. Nursing Times; 103: 45, 23-24.
The Department of Health has recently announced the introduction of a routine human papilloma virus (HPV) vaccination programme for girls aged 12–13 years to protect against cervical cancer, starting from September 2008 (DH, 2007). There will also be a two-year catch-up campaign for girls aged up to 18, starting in autumn 2009.
This decision follows advice from the Joint Committee on Vaccination and Immunisation (JCVI), whose recommendations are based on a detailed review of evidence surrounding HPV vaccination (see box).
The DH emphasises that the comprehensive cervical screening programme will continue after the HPV vaccine has been introduced. It explains that this is because the vaccine does not protect against all HPV types that may cause cervical cancer.
HPV is transmitted through sexual contact and causes 99% of invasive cervical cancer. The DH (2007) says that vaccination will offer protection against the two strains that cause 70% of all cervical cancer. It explains that to ensure maximum benefit and protection from this vaccine, it would be necessary to administer it before the onset of sexual activity.
On the incidence of HPV, the DH says that at some time in their lives, most people will be infected with HPV. In the UK, HPV DNA (indicating current infection) has been found in 40% of women aged 20–24. In England in 2004, 2,221 new cases of invasive cervical cancer were diagnosed. According to the DH, this vaccine will save the lives of approximately 400 women each year.
HPV and cervical cancer
In a commentary article on HPV vaccines published last month, Stanley (2007) provides further detail on HPV and its link with cervical cancer. She explains that more than 100 types of HPV have been isolated from clinical biopsies.
Some 30–40 HPVs regularly or sporadically infect the genital tract and here they fall into two groups – low-risk viruses such as HPV 6 and 11 that cause genital warts, and high-risk viruses associated with anogenital cancer.
Infection with one of a subset of 15 high-risk HPVs is the main cause of invasive cervical cancer but two types – HPV 16 and 18 – cause more than 70% of cervical cancers. HPV 16 is detected in more than 50% of cases and HPV 18 in 7–20% (irrespective of the geographical location) (Stanley, 2007).
Two prophylactic HPV vaccines have been developed. These are Cervarix, a bivalent HPV 16/18 vaccine from GlaxoSmithKline, and Gardasil (also known as Silgard), a quadrivalent HPV 16/18/6/11 vaccine from Merck (Stanley, 2007). The results of trials of both vaccines have demonstrated high efficacy.
Impact of vaccination
Although there is – as yet – no definite proof that vaccination will actually prevent cancers (White, 2007), various models have attempted to show the potential impact of HPV immunisation.
Kohli et al (2007) estimated the impact of HPV 16/18 vaccination on cervical cancer and deaths, precancerous lesions and screening outcomes for a vaccinated cohort of 12-year-old girls in the UK, using a mathematical model.
The researchers found that among this group there would be an estimated reduction of 66% in the prevalence of high-grade precancerous lesions and a 76% reduction in deaths from cervical cancer. They concluded that it is feasible to forecast the potential effects of HPV vaccination in the context of an existing national screening programme. The authors added that the results suggest a ‘sizeable reduction in the incidence of cervical cancer and related deaths’.
Stanley (2007) also explores the potential impact if a ‘magic wand’ was waved and all women aged 9–26 were vaccinated tomorrow. She concludes that after 1–3 decades the vaccinated cohort should show a reduction of 70% in the incidence of cervical cancer and adds that if screening were to continue and its coverage were maintained at current levels then the reduction could reach more than 90%.
If HPV 6 and 11 are included in the vaccine mix Stanley states that in a reasonably short time period genital wart incidence would be reduced by more than 90%. She concludes: ‘This really does look like the beginning of the end for HPV-associated disease in women.’
Older women and screening
The DH (2007) states that JCVI advice is that it would not be cost-effective to run a national vaccination programme for all women over the age of 18. This is because as soon as a woman has started her sexual life she is at risk of catching the virus. However, the DH points out that women not covered by the vaccination programme will still be invited to be screened routinely as part of the national cervical screening programme.
Stanley (2007) also examines the issue of vaccination in older women. She agrees that, since the screening programme will have to continue for the foreseeable future, vaccination of older women is unlikely to be cost-effective compared with vaccination of the younger age group.
Stanley also stresses that the current vaccines only include two of the 15 oncogenic HPV types and – even if delivered optimally with 100% coverage – would prevent only 70% of cervical cancers in the long term.
She concludes: ‘It is critical, therefore, that women do not perceive the vaccine as a “magic bullet” giving complete protection against cervical cancer. They must continue in the screening programme, vaccinated or not. Screening methods may change in the medium term but until a vaccine is available that prevents 90% or more of invasive cervical cancers, the need for the screening programme will continue.’
The DH confirms that the national screening programme will continue, as vaccination will not protect against all forms of cervical cancer and women who have not received the vaccine will remain unprotected.
Primary care trusts will plan how to deliver the vaccination programme locally. The JCVI has advised that HPV vaccination would be most efficiently delivered through schools, and NT reported last week that the DH said the vaccine is likely to be administered by nurses in schools, with the catch-up being undertaken by GP surgeries (NT News, 30 October, p3).
The ongoing HPV vaccination programme will be introduced for girls aged 12–13 years (school year 8) from autumn 2008 (DH, 2007), while the catch-up programme will start in autumn 2009 and will run for two years:
Girls aged 16–18 years (school years 12 and 13) will be offered the vaccine from autumn 2009;
Girls aged 15–17 years (school years 11 and 12) will be offered the vaccine from autumn 2010.
By the end of this catch-up programme all girls under 18 will have been offered the HPV vaccination. Three doses of the HPV vaccine administered over a six-month period are needed for protection. No decision has yet been reached on which of the two licensed vaccines, Gardasil and Cervarix, will be used.
As with other vaccines, side-effects such as a sore arm and a mild temperature, do occur. However, the vaccines have undergone rigorous safety testing as part of the licensing process. HPV vaccine is given in other countries, including the US and Australia (DH, 2007).
It is likely that nurses will play a part in delivering this important aspect of the NHS immunisation programme. They are also crucial in ensuring that women still attend for cervical screening to prevent them from developing cervical cancer.
Department of Health (2007) HPV vaccine recommended for NHS immunisation programme. DH press release, 26 October, 2007.
Kohli, M. et al (2007) Estimating the long-term impact of a prophylactic human papilloma virus 16/18 vaccine on the burden of cervical
cancer in the UK. British Journal of Cancer; 96: 1, 143–150.
Stanley, M. (2007) HPV vaccines: where are we now? Journal of Family Planning and Reproductive Health Care;
33: 4, 227–229.
White, C. (2007) How will the public respond to an HPV immunisation scheme? Nursing Times; 103: 11, 9.
After a detailed review of the evidence, the JCVI recommended:
It acknowledged that a catch-up programme for all women aged 18–25 years was unlikely to be cost-effective but could benefit some individuals. The DH will consider this further.
The committee did not make a recommendation about which of the two licensed HPV vaccines should be offered.