The 9-valent human papillomavirus vaccine was well tolerated in 16-26 year olds and had a safety profile comparable to that of the quadrivalent vaccine, according to an analysis of seven phase III trials.

“The demonstrated efficacy and favorable safety profile of the 9vHPV vaccine support widespread vaccination programs,” reported Dr. Edson D. Moreira Jr. and his associates in Pediatrics.

Vaccines were given in a three-dose regimen: 15,776 male and female patients received at least one dose of the 9-valent vaccine and 7,391 control subjects received at least one dose of the quadrivalent vaccine.

Frequencies of vaccine-related systemic adverse events such as headache and pyrexia were “generally similar” between the two vaccine groups, the investigators reported.

Compared with the quadrivalent vaccine, the 9-valent vaccine was associated with significantly more frequent adverse events at the injection site, including pain (84% vs. 90%), swelling (29% vs. 40%), and erythema (34% vs. 26%). Most of these reactions in both groups were mild to moderate in intensity, however.

Discontinuations and vaccine-related serious adverse events in the 9-valent vaccine group were rare (0.1% and less than 0.1%, respectively).

Read the full study here (doi:10.1542/peds.2015-4387).