The nine-valent HPV vaccine, Gardasil 9, showed long-term effectiveness in preventing cervical cancer cases, according to a study published in The Lancet.
The FDA approved Gardasil 9 in 2014. The vaccine targets nine genotypes of HPV known to cause cervical cancer as well as vulvar, vaginal and anal cancers and genital warts caused by HPV.
Researchers followed 14,215 women in 18 countries for up to six years after the first vaccine shots to determine the vaccine's efficacy at preventing the disease. They followed the women for another five years to examine the vaccine's ability to produce infection-halting antibodies against the nine genotypes of HPV. Half the women were vaccinated with the earlier approved four-valent Gardasil and half with the nine-valent Gardasil 9.
Researchers found Gardasil 9 demonstrated 97.4 percent efficacy in preventing infections and disease caused by the five additional HPV genotypes not included in the four-valent Gardasil vaccine. Additionally, Gardasil 9 vaccination produced similar antibody protection against the four HPV genotypes in Gardasil.