nine-valent human papilloma virus vaccine, Gardasil 9 shows long-term
effectiveness, strengthening the promise that it can reduce 90% of cervical
cancers, according to the findings of a study published in The Lancet this week.

study of 14 215 women in 18 countries extends and solidifies the initial phase
3 efficacy and safety trial of the vaccine that was published in February 2015
The New England Journal of Medicine.

“There is no
question that the vaccine works,” said primary author Warner Huh, MD, professor
and director of the University of
Alabama at Birmingham Division of Gynecologic Oncology and a senior
scientist at the UAB Comprehensive
Cancer Center. “We’re on the verge of a dramatic change that will
positively affect all individuals. The challenge is to get the new vaccine into
widespread use among young women.”

Gardasil 9 was
approved by the FDA in December 2014. The vaccine immunises against nine
genotypes of HPV known to cause cervical cancer, as well as vulvar, vaginal and
anal cancers and genital warts caused by HPV. It is an advance over the
four-valent HPV vaccine, Gardasil, which was approved by the FDA in 2006.

Huh helped
develop and test Gardasil, which targets the two HPV genotypes known to cause
about 70% of cervical cancer and two other genotypes that cause genital warts.
Gardasil 9 targets those four genotypes and five additional ones as well. Both
vaccines are prophylactic, meant to be given before females or males become
exposed to possible HPV infection through intimate contact.

“With this new
vaccine, there is a very legitimate opportunity to wipe out cancers that are
caused by HPV, particularly cervical cancer in women,” Huh said.

years ago, cervical cancer was a very common cause of mortality in the United
States. Looking forward, with widespread vaccination, it is highly likely that
cervical cancer will evolve into historical interest only, and screening, like
Pap smears, might go away altogether. HPV vaccines are one of the most
scrutinised vaccines ever, but multiple studies have demonstrated the vaccine
to be safe and well-tolerated.”

In The Lancet study, women were followed
for efficacy at preventing disease for up to six years after the first vaccine
shots, and they were followed for production of infection-halting antibodies
against the nine genotypes of HPV for more than five years. The randomised double-blind
efficacy, immunogenicity and safety study involved 105 sites in Austria,
Denmark, Germany, Norway and Sweden; Brazil, Chile, Colombia and Peru; Canada,
Mexico and the United States; and Hong Kong, Japan, New Zealand, South Korea,
Taiwan and Thailand.

Half the women
were vaccinated with the four-valent Gardasil and half with the nine-valent
Gardasil 9. They were followed via gynaecological exams for evidence of
infections or disease, and their blood sera were tested for antibody levels
against HPV.

Gardasil 9 showed
97.4% efficacy to prevent infections and disease caused by the five additional
HPV genotypes not included in the four-valent Gardasil vaccine. Gardasil 9
vaccination produced similar antibody protection against the four HPV genotypes
in Gardasil. The two vaccines also had similar safety profiles.

The nine-valent
HPV vaccine has now been licensed in more than 60 countries for prevention of
HPV-related anogenital cancers and precancers, and genital warts.


Reference: Huh W, et al. Final efficacy, immunogenicity, and safety analyses of a nine-valent
human papillomavirus vaccine in women aged 16–26 years: a randomised,
double-blind trial. The Lancet.
Published 5 September 2017.