Cervarix effective for at least six years

By Mark Pownall

The HPV vaccine Cervarix - used in the UK programme - is effective for about six years, and probably much longer, the final analysis of a long term study has found.

The study was a follow up of a clinical trial of 1,113 women aged 15-25 who initially had a normal cervical profile and no evidence of infection with HPV 16 or 18, or 12 other types of HPV known to cause cancer.

The women in the study gave cervical swabs every six months which were tested for HPV DNA, and were followed up for up to 6.4 years, with a mean of 5.9 years.

The vaccine provided 95% protection against HPV infection, 96.7% protection against cytological changes, and 100% protection against cervical intraepithelial neoplasia 2+ associated with HPV 16 and 18. The protection against all CIN2+ neoplasias was 72%.

Lead researcher Professor Cosette Wheeler, head of molecular genetics and microbiology at the University of New Mexico School of Medicine said: ‘The vaccine confers sustained protection and that efficacy does not wane up to 6.4 years after first vaccination. Vaccine efficacy against persistent infection with HPV-16/18 remained 100%. Further assessment is necessary but we expect protection to continue for many more years.'

The Lancet, published online December 3, 2009.