ANALYSIS:A formal immunisation programme against cancer-causing HPV will raise complex concerns
WITH MINISTER for Health Mary Harney on record as saying she will introduce a HPV/cervical cancer vaccine programme if advised to do so, yesterday's publication of a Health Information and Quality Authority (Hiqa) value-for-money report should pave the way for the early announcement of a formal immunisation programme.
Cervical cancer is caused by certain types of the human papilloma virus (HPV), with evidence of infection found in 99 per cent of women with cervical cancer. Although there are in excess of 200 HPV strains, just a small number are associated with the development of cancer of the cervix. HPV types 16 and 18 are found in almost 70 per cent of cervical cancers, while another five sub-types are responsible for a further 20 per cent of cases. Some non-cancerous HPV types are linked to the presence of warts in the genital area.
Cancer of the neck of the womb (cervix) is diagnosed in almost 200 women here every year; some 70 to 90 women die of the disease annually. Cervical cancer usually develops slowly, passing through pre-invasive stages before progressing to the full-blown disease. If caught in the early stages, it has a five-year survival rate of 80 per cent or greater.
HPV is a sexually transmitted infection; it is estimated that almost 80 per cent of sexually active people have been infected with at least one virus type by the age of 50. It is usually symptomless and in 90 per cent of cases the body clears itself of the virus within two years. But it is when the virus persists that the risk of cervical cancer increases.
Gardasil and Cervarix are the approved vaccines against HPV. Both aim to prevent cervical cancer; in addition, Gardasil is active against those HPV sub-types known to cause genital warts. Both products involve a three-vaccine course, given over a six-month period. Clinical trials involving a five-year follow-up have shown that vaccination is 100 per cent effective in preventing HPV infection and non-invasive cancer.
HPV vaccines must be given before infection with the virus occurs. This means administering the course prior to the person becoming sexually active, so a comprehensive vaccination programme would need to be administered to girls in the 11- to 13-year age bracket.
The Hiqa report did not deal with any ethical issues that may arise from vaccinating pre-pubertal girls: might some parents have a problem vaccinating their children against a sexually transmitted disease? Could a vaccination programme be interpreted as condoning sexual activity in teenagers?
Other issues of possible concern include the confirmation in yesterday's report that further evidence is required to establish the long-term safety and efficacy of HPV vaccination. Nor do the vaccines have a proven therapeutic value for those already infected with HPV. And the fact that some 30 per cent of cervical cancers are caused by HPV types not contained in the vaccines means there will be an ongoing need for a national cervical screening programme.
The National Centre for Pharmoeconomics, which carried out the assessment of HPV vaccination for Hiqa, found that an immunisation programme aimed at 12-year-old girls, costing almost €10 million per annum and achieving coverage of 80 per cent, is cost-effective. However, there was less clear-cut evidence that a catch-up programme for 13- to 15-year-olds could be justified on cost grounds.
The Minister will have to make a judgment call on cost, efficacy and safety issues before she gives a final go-ahead for a national HPV vaccine programme.