Cervarix 'highly effective at preventing cervical cancer'
By Lilian Anekwe
The Cervarix vaccine against cervical cancer provides some cross-protection against several other cancer-causing strains of the HPV virus, a new analysis published online in The Lancet has found.
The Department of Health chose Cervarix, which offers protection against HPV 16 and 18 viruses, for its school-based cervical cancer vaccination programme.
But the PATRICIA trial, published online in The Lancet today, found the vaccine also shows cross-protective efficacy against a further 12 other oncogenic HPC types closely related to HPV 16 and 18.
The international trial of 18,000 women aged 15 to 25 included two cohorts of women: one which included sexually active young women and another of sexually inactive women with no previous exposure to HPV infection.
After nearly three years of follow-up researchers found the vaccine protected against 93% of CIN2+ lesions caused by HPV 16 or 18.
But the vaccine was also effective against 30% of CIN2+ lesions, irrespective of the HPV type, in the sexually active cohort, and 70% of lesions in the naïve cohort.
It also protected against 33% of CIN3+ lesions in the pre-exposed cohort and 87% of lesions in the naïve cohort.
Overall, the researchers calculated the vaccine's efficacy at between 37% and 54% against 12 non-vaccine oncogenic HPV types.
Given around 70% of cervical cancer is estimated to be caused by HPV-16/18, researchers estimated the cross-protective efficacy of this vaccine could represent 11-16% of additional protection against cervical cancer to that afforded by efficacy against HPV-16/18.
Lead researcher Professor Jorma Paavonen, professor of obstetrics and gynaecology at the University of Helsinki in Finland, concluded: ‘The vaccine showed high efficacy against CIN2+ that was associated with HPV-16/18 and non-vaccine oncogenic HPV types, and substantial overall effect in cohorts that are relevant to both vaccination and catch-up programmes.'
‘Although the importance of continued tests for pap or HPV in vaccinated and unvaccinated women must be emphasised, HPV vaccination has the potential to substantially reduce the incidence of cervical cancer and precancer, and the numbers of colposcopy referrals and cervical excision procedures.'The Department of Health chose Cervarix, which offers protection against HPV 16 and 18 viruses, for its school-based cervical cancer vaccination programme The Department of Health chose Cervarix, which offers protection against HPV 16 and 18 viruses, for its school-based cervical cancer vaccination programme