Experts warn on cervical cancer vaccination plan
HEALTH AUTHORITIES and governments must be cautious about introducing large-scale vaccination programmes against cervical cancer, international experts have warned.
In research with direct relevance to this month's decision by Minister for Health Mary Harney to give the go-ahead to the introduction of a cervical cancer vaccination programme next year, public health doctors from Harvard University in Boston and Oslo in Norway have warned there was a need for more certain answers to issues surrounding the vaccination of adolescent girls against the human papilloma virus (HPV), which causes cancer of the cervix.
Writing in the latest issue of the prestigious medical journal, The New England Journal of Medicine(NEJM), published today, the experts say they are concerned that life-long immunity cannot be guaranteed by the vaccine and that questions remain about its ability to reduce deaths from cervical cancer.
The experts, who carried out an analysis of the health and economic impact of HPV vaccination, also question whether the vaccine, which acts against two particular strains of the HPV virus, will allow other, potentially cancer causing strains, to multiply. However, their concerns have been played down by experts and health authorities here, who said last night that the issues raised in the NEJM had been carefully considered by the authors of an advisory report published by the Health Information and Quality Authority (Hiqa).
Pointing out that the health technology assessment (HTA) report looked at the cost-effectiveness of a combined national HPV vaccination and cervical cancer screening programme, a spokesman for Hiqa said: "The report addressed issues on the duration of protection of the vaccines, including the potential need for a booster dose at 10 years."
"The authority stressed the importance of ongoing monitoring of both the safety and efficacy of the two vaccines evaluated in the report, while highlighting that future research may develop other vaccines that cover a broad range of HPV types."
Dr Michael Barry, the director of the National Centre for Pharmacoeconomics (NCPE), which carried out the study into the cost-effectiveness of the vaccine here, said it indicated the vaccination of 12-year-old girls with the HPV vaccine should offer value for money.
"The conclusions of HTAs conducted in different healthcare settings are not readily transferrable. Therefore it is not unusual to observe technologies being cost effective in some countries and not in others," he said, although he emphasised that in this case, "the findings (in the NEJM) that HPV vaccination was not cost effective for older girls and women is in agreement with the Irish HTA".
Speaking on behalf of the Irish Cancer Society, Dr Gráinne Flannelly, consultant obstetrician and gynaecologist at the National Maternity Hospital, Holles Street, Dublin, said that contrary to concerns expressed by the study authors, recent research showed some of those vaccinated had developed immunity to sub-types of the HPV virus not contained in the vaccine. But she acknowledged the uncertainties expressed by the NEJM authors were "valid".
Dr Flannelly emphasised that the concerns raised by the US experts had been addressed by the Hiqa report.
The NEJM editorial, " HPV Vaccination - reasons for caution", warns that certain assumptions about the vaccine needed to be challenged. "Whether these assumptions are reasonable is exactly what needs to be tested in trials and follow-up studies. If the authors' [of the research] baseline assumptions are not correct, vaccination becomes less favourable and even less effective than screening alone", it says.
However, a spokeswoman for the Minister said her decision to begin planning for the introduction of a HPV vaccination programme next year was "not inconsistent with the prudent approach advocated in the NEJM".