Statement to Science Media Centre
Uptake
As at 31 July 2009, more than 81,000 New Zealand girls and young women have chosen to have the HPV immunisation.
Around 40 percent of young women born in 1990 or 1991 who have been eligible to have the vaccine for free through their GP, local health clinic or family planning since September 2008 have had the vaccine.
At the beginning of the year the programme was extended to younger girls, mainly through schools. Around half of the girls offered the programme in schools during 2009 have taken it up.
“As cervical cancer develops over many years, the benefits of the programme in reducing cervical cancer rates will not be evident for some time although the reduction in HPV infection and abnormal cervical changes will be apparent much sooner.” says Dr Greg Simmons, chief advisor population health.
“Young women who are taking up the programme are taking a positive step that will reduce their risk of developing cervical abnormalities or receiving an abnormal smear test result when they are older,” Dr Simmons says.
Women aged 20 to 70 years need to continue to have regular smears to prevent cervical cancer. Young women who have the HPV vaccine will reduce their likelihood of having abnormal cervical smear test results.
Preliminary findings from a local study[1] by Professor Christopher Fairley of the University of Melbourne compare the proportion of new genital warts diagnoses at the Melbourne Sexual Health Centre before and after the introduction of HPV immunisation and shows a 48 percent decline in cases among young women under the age of 26 only one year after vaccination commenced.
Adverse Events Following Immunisation
Adverse events following immunisation in New Zealand are taken seriously. Suspected adverse events are notified to the Centre for Adverse Reaction Monitoring (CARM) at the University of Otago. CARM is an agency independent of the Ministry of Health and Medsafe. CARM regularly reports to Medsafe and reports are independently reviewed every quarter by the Medicines Adverse Reactions Committee.
Adverse event reporting in New Zealand (as in other many other countries) is through a passive surveillance system. This is when health professionals and the public voluntarily provide reports to CARM. Each report is then assessed by an expert medical professional as to whether the reaction was likely to be caused by the vaccine or not.
Adverse events following immunisation with the HPV vaccine in New Zealand are in keeping with expected events following any immunisation, clinical trial results and observations from national reporting in other countries.
· 146,955 doses of the HPV vaccine are recorded on the National Immunisation Register as having been administered in New Zealand to 30 June 2009.
· As at 26 June 2009, a total of 155 reports of suspected adverse events following HPV immunisation have been received by CARM. These reports relate to young women immunised as part of the publicly-funded HPV immunisation programme as well as individuals who have obtained the HPV vaccine privately. Ten reports were prior to the start of the publicly-funded HPV immunisation programme on 1 September 2008.
· Overall, the majority of reactions reported are local reactions such as soreness, swelling or redness at the injection site, raised temperature, headache, nausea, skin reactions – mostly rash and fainting. All of these are known side effects listed in the Gardasil data sheet and Consumer Medicine Information.
· Fainting episodes were described in 17 reports. Fainting episodes have been well described internationally in vaccination campaigns – particularly in mass immunisation settings and where school aged recipients are involved.
· Of the 155 reports of adverse events following HPV immunisation, only one is classified by Medsafe as serious. This report related to the hospitalisation of an individual with a pre-existing condition two weeks after immunisation. The likelihood of this event being caused by the vaccine is still being evaluated, but it appears unlikely.
Overall Medsafe considers the adverse events reported following HPV immunisation to be similar to those reported during clinical trials and observations from national reporting in other countries.
The Medicines Advisory Reactions Committee is an expert advisory committee appointed by and accountable to the Minister of Health. It was established to advise the Minister about adverse reactions to medicines and vaccines and their risk-benefit profile.
As its June 2009 meeting, the Committee reveiwed reports to 31 May 2009 and agreed that the pattern of adverse events following HPV immunisation do not raise any concerns, and noted that reports will continue to be regularly reviewed. The Committee’s minutes are online at: http://www.medsafe.govt.nz/profs/adverse/Minutes138.htm#4.3
Background
The inclusion of HPV vaccination into New Zealand’s Immunisation Schedule was recommended by the Ministry of Health’s Immunisation Technical Working Group in November 2006. The Government announced the Programme in May 2008. At that time, publicly funded HPV immunisation programmes were already well underway overseas. For example, Australia’s HPV immunisation programme commenced in April 2007.
HPV immunisation was added to the New Zealand National Immunisation Schedule for girls in school year 8 (or age 12) on an on going basis from 1 January 2009.
A catch-up programme is also offered to young women born on or after 1 January 1990. The catch up programme began on 1 September 2008 for girls born in 1990 and 1991 and was extended to girls born from 1992 onwards from 1 January 2009.
The main aim of the HPV Immunisation Programme is to protect young women from HPV infection which can lead to pre-cancerous cervical abnormalities which, if undetected and untreated, can lead to cervical cancer later in life.
The HPV vaccine has been shown to be effective in protecting against four strains of HPV – those responsible for 70% of cervical cancer, the majority of vulva and vaginal cancers, and 90% of genital warts.
In terms of length of protection, on going clinical studies show that after five years, protection remains high and suggest that protection will last much longer[2]. “Immune memory” has also been demonstrated which is indicative of long-lasting, possibly even life-long immunity[3], although further studies will be required in the long-term to confirm this. At this stage it is expected that a booster will not be required.
[1] Fairley K Decline in presentations of genital warts one year after implementation of a quadrivalent Human Papillomavirus vaccination program in young women. 25th International Papillomavirus Conference, May 8-14 Malmö Sweden
[2] Villa LL, Costa RLR, Petta CA, et al. High sustained efficacy of a prophylactic quadrivalent human papillomavirus types 6/11/16/18 L1 virus-like particle vaccine through 5 years of follow-up. Br J Cancer 2006;95:1459-1466.
[3] Olsson SE, Villa LL, Costa RL et al. Induction of immune memory following administration of a prophylactic human papillomavirus (HPV) types 6/11/16/18 L1 virus-like particle (VLP) vaccine. Vaccine 2007;25:4931-4939.