Quadrivalent HPV vaccine effective in women aged 24 to 45

The human papillomavirus vaccine for types 6, 11, 16 and 18 was effective in more than 90% of women aged 24 to 45 years who were not already infected with the studied disease types at enrollment.

Researchers conducted a trial from 2004 to 2005 at several sites in Bogota, Colombia.

They randomly assigned 1,911 women to receive a dose of the quadrivalent human papillomavirus (HPV) vaccine at day one, month two and month six and 1,907 women to receive placebo using the same schedule.

There were two primary endpoints: duration of infection of more than six months and cervical and external HPV disease due to types 6, 11, 16 or 18, or due to types 16 and 18 only.

In the per-protocol population, the vaccine demonstrated efficacy against disease or infections related to all four types of HPV in 90.5% of women (95% CI, 73.7-97.5). The vaccine was effective in 83.1% of women with disease or infections related to types 16 and 18 (95% CI, 50.6-95.8).

The researchers also calculated intention-to-treat results in women who had infections at baseline. The vaccine demonstrated that the vaccine was effective against 30.9% of disease or infections caused by all four types (95% CI, 11.1-46.5) and was effective 22.6% of the time in women with infections caused by types 16 and 18 (95% CI, –2.9-41.9).

The researchers reported no adverse events related to the vaccine.

Munoz N et al. Lancet. 2009; 373:1949-1957.