Human papillomavirus (HPV)-associated cervical cancer affects almost half a million sexually active females each year worldwide. Recently, however, clinical trials of two HPV vaccines have demonstrated successful results

Greenwell, P.

Rughooputh, S.

WestminsterResearch

     University of Westminster Eprints http://eprints.wmin.ac.uk   Vaccination against cervical cancer.  Pamela Greenwell Sanjiv Rughooputh  School of Biosciences    This is an electronic version of an article published in Biomedical Scientist, 49 (6). pp. 441-442, May 2005.       The Eprints service at the University of Westminster aims to make the research output of the University available to a wider audience.  Copyright and Moral Rights remain with the authors and/or copyright owners. Users are permitted to download and/or print one copy for non-commercial private study or research.  Further distribution and any use of material from within this archive for profit-making enterprises or for commercial gain is strictly forbidden.        Whilst further distribution of specific materials from within this archive is forbidden, you may freely distribute the URL of the University of Westminster Eprints (http://eprints.wmin.ac.uk).   In case of abuse or copyright appearing without permission e-mail wattsn@wmin.ac.uk. Human papillomavirus (HPV)-associatedcervical cancer affects almost half amillion sexually active females each yearworldwide. Recently, however, clinicaltrials of two HPV vaccines havedemonstrated successful results. The Gardasil vaccine (Merck) targets HPVtypes 16 and 18, which are associated withcervical cancer, and also HPV types 6 and 11,which are associated with genital warts. Inthe trial, 552 women aged 16–23 wererecruited from Brazil, Europe and USA, andthe study was carried out by the LudwigInstitute for Cancer Research in Brazil. A total of 277 women were randomlyassigned to be given the vaccine and receivedinjections on the first day of the study, andthen again after two and six months. Theparticipants were followed up for 36 monthswith regular gynaecological examinations. Among the women who received aplacebo, 36 contracted HPV or developed one of the diseases associated with the virus.Of these 36 women, three developed genitalwarts and three developed precancerouscervical lesions. Among the women whoreceived the vaccine, four contracted HPVbut none developed any of the diseasesassociated with the virus. Although HPV antibody levels fell at theend of the study period among women whoreceived the experimental vaccine, antibodylevels were higher in this group than inwomen naturally infected with HPV.According to the researchers, the vaccine was89% effective in preventing infection with thefour HPV types, and 100% effective inpreventing the diseases associated with thesetypes. Elsewhere, GlaxoSmithKline has reportedthat its new vaccine Cervarix shows thepotential to prevent more than 70% ofcervical cancers in phase 2 clinical trials. As with the Gardasil vaccine, Cervarix targetsHPV types 16 and 18. Interestingly, participants in the two trialswere young (16–23 years) and some studieshave shown that most HPV-infected womenin this age group will not show any evidenceof infection for six to 12 months afterexposure and that 80% clear the infectionafter 18 months. However, both companieshave now moved to phase 3 clinical trials and have recruited around 20,000participants each. GlaxoSmithKline plans tofile for regulatory approval for Cervarix inEurope in 2006, while Merck plans to applyfor US Food and Drug Administration (FDA)approval in late 2005.Both companies would like to make thesevaccines available to children as young as 10,before they become sexually active. However,it may prove difficult to convince parents ofthe need to vaccinate their children againsta potential sexually transmitted disease atthis age. There is a school of thought tosuggest that the vaccine should be given tobabies, thus circumventing discussions of ageof first sexual activity, but some cultures mayview HPV vaccination as unethical and ruleit out completely. Although these two vaccines target HPVtypes 16 and 18, which account for morethan 80% of cervical cancer-associatedinfection, there are other high-grade HPVs,such as types 31, 33 and 39, not covered by the vaccines. Hence, these two vaccines, if used, would not give protection against allhigh-grade HPV types. Furthermore, the economic cost wouldmake it impossible for developing countriesto adopt these vaccines in the short-term, but the cost could be outweighed by the costof treating patients affected with cervicalcancer. Even if the vaccine is successful andthere are developments of new vaccines tocover all HPV types, it should be rememberedthat the vaccine will be of little use to thosealready infected and that screening, diagnosisand treatment will be required for decadesto come. Clearly, although these vaccines will contribute to the fight against cervicalcancer, they are not the entire solution to the problem. nARTICLEVaccination againstcervical cancerHuman papillomavirus-associated cervical cancer is a worldwide problem and vaccines against certain virus types are under development. Here, PamelaGreenwell and Sanjiv Rughooputh take a brief look at the current position.THE BIOMEDICAL SCIENTIST   May 2005 441‘Studies have shownthat 80% of youngwomen (16–23 years) clear an HPV infectionafter 18 months’Although HPV typesAlthough HPV types 16 and 18 account for more than 80% of cervical cancer-associated infection, other high-grade types are not covered by the vaccinesPamela Greenwell and Sanjiv Rughooputhare members of the Molecular and MedicalMicrobiology Research Group at theUniversity of Westminster, London, and are WestFocus Knowledge Transfer Fellows. 

Vaccination against cervical cancer

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Vaccination against cervical cancer

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