Public Health and Communicable Diseases - SA Health - SA.Gov.au

cancer among aboriginal women. This represents morethan nine times the death rate of non-aboriginal women(3.0 per 100, 000 women). 11In some countries the incidence of cervical cancerappears to be increasing due to recent changes in risktaking behaviour in young women. 13 There was a 60%increase in incidence of cervical cancer in Finland inthe 1990s in young women. Over the same period oftime the number of lifetime sex partners significantlyincreased and the age at first intercourse decreased. 13Thus increasing exposure to HPV and other sexuallytransmitted infections is likely to explain the recentincrease in the incidence of cervical cancer observed inFinland in young women.Population studies in the 1980s and 1990s in variouscountries detected an association between humanpapilloma viruses (HPV) and cervical cancer. 14 Cervicalinfection with HPV is extremely common compared tothe incidence of cervical cancer. 15 However, particulartypes of HPV have a strong association with persistent14, 16-18infection and a high incidence of cervical cancer.Human Papilloma Virus as a cause of Cervical CancerThe association of cervical cancer and infectionwith a high-risk HPV type is supported by strongepidemiological evidence and by the detection ofHPV DNA in up to 99.7% of cervical cancers from allgeographic areas. 19 There are over 40 types of HPV,with 14 of these considered to be oncogenic. HPV16 isthe most prevalent high-risk HPV type and is presentin approximately 50% of cervical tumor specimensworldwide. HPV18 is the second most prevalent typeand is associated with approximately 16% of cervicalcancers, with the remaining tumors containing DNAfrom other high-risk types such as HPV45, 31 and 33. 20The persistence of HPV in the genital tract is a riskfactor for development of cervical cancer. 16-18Approximately 470,000 new cases of cervical cancerare diagnosed each year, and nearly 200,000 deathsare attributable to the disease. 21-23 Consequently, thesocial and economic costs of HPV-induced diseasesof the genital tract are enormous, and development ofprophylactic vaccines has been an important initiative.Human Papilloma Virus VaccineVaccines against the high-risk types HPV-16 and HPV-18 have been shown to be safe and immunogenicin previous trials, and have prevented incident andpersistent HPV-16/18 infection. The HPV vaccine isan inactivated virus vaccine which is not capableof replication or transfer of the virus to others. Twovaccines have been developed that are likely to beavailable in the next 12 months. Merck and Co. havedeveloped a quadrivalent vaccine, Gardasil whichcontains HPV 16, 18 (oncogenic types) and HPV 6and 11, benign types that are associated with genitalwarts. A bivalent vaccine, Cerverix has been developedby GSK which contains the leading oncogenic types,16 and 18. In Phase II and III studies, HPV vaccineshave been shown to be safe and 100% effective inpreventing persistent HPV infection. Recent publishedresults from a long term follow-up study of Cerverix,indicates long term (up to 4.5 years) protection againstpersistent infection and cervical intraepithelial neoplasia(CIN) changes with evidence of cross protection againstother oncogenic serotypes not included in the vaccine,including serotype 45. 24Pre-teen and young adolescent women will be animportant target population for vaccination, since itwill be important to protect prior to onset of sexualactivity and exposure to oncogenic HPVs. For HPVvaccine program to be effective, high coverage ratesespecially in high risk groups will need to be achieved.Linkages with other health care systems, improvedadult health services and education about the benefitsand availability of the HPV vaccine will be vital to theachievement of high levels of coverage. Implementationissues including provision of Government funding,decisions on whether both males and females willreceive the vaccine and the target age group are yet tobe determined.The future challenge for these new vaccines will beto develop innovative funding strategies to ensureadequate vaccine delivery to populations with thehighest burden of disease.References1. Global Alliance For Vaccines and Immunisation (GAVI).Fact sheet no. 169, March 2001.2. Parashar U, Hummelman E, Bresee J, Miller M et al.Global illness and deaths caused by rotavirus diseasein children. Emerg infect Dis. 2003;9:565-72.3. Bresee J, Glass R, Ivanoff B, Gentsch JR. Currentstatus and future priorities for rotavirus vaccinedevelopment, evaluation and implementation indeveloping countries. Vaccine. 1999;17(18):2207-22.4. Galati J, Harsley S, Richmond P, Carlin J. Healtheconomics and hospitalization data for RV infection.(Accepted to Aust N Z J Public Health subsequent tomanuscript amendment).5. Bonhoeffer J, Heath P. Update on new vaccinesand immunisation strategies. Current Paediatrics.2006;16:1-7.6. Simonsen L, Viboud C, Elixhauser A, Taylor R. More onRotaShield and intussusception: the role of age at thetime of vaccination. J Infect Dis. 2005;192(Suppl. 1):S36-43.7. Vesikari T, Matson D, Dennehy P, Van Damme P. Safetyand Efficacy of a Pentavalent Human – Bovine (WC3)Reassortant Rotavirus Vaccine. N Engl J Med.2006;354:23-33.8. Ruiz-Palacios G, Pérez-Schael I, Raúl Velázquez F,Abate H et al. Safety and Efficacy of an AttenuatedVaccine against Severe Rotavirus Gastroenteritis. NEngl J Med. 2006;354:11-22.9. Ponten J, Adami H,Bergstrom R,Dillner J, FribergL, Gustafsson l, Miller A, parkin D, Sparen P,Trichopoulos D. Strategies for global control ofcervical cancer. Int J Cancer. 1995;60:1-26.24