Safety, Tolerability, and Immunogenicity of Gardasil Given Concomitantly With Menactra and Adacel

OBJECTIVES: Multinational phase III trials of a human papillomavirus vaccine, Gardasil, have shown the vaccine to be generally well-tolerated, efficacious, and immunogenic. We evaluated the immunogenicity and safety of Gardasil administered concomitantly with Menactra and Adacel.

METHODS: In this open-label study, boys (n = 394) and girls (n = 648) aged 10 to 17 were randomly assigned in a 1:1 ratio as follows: group A (concomitant administration) received a 0.5-mL dose of Gardasil at day 1, month 2, and month 6 and a 0.5-mL dose of Menactra and Adacel on day 1; group B (nonconcomitant administration) received Gardasil at day 1, month 2, and month 6 and Menactra and Adacel at month 1. Antibody levels for all vaccine components were measured. Systemic, injection-site, and serious adverse experiences (AEs) were monitored.

RESULTS: Immune responses after concomitant administration of the 3 vaccines were noninferior to nonconcomitant administration. Seroconversion for Gardasil was ≥99% in both groups A and B. For Menactra and Adacel, concomitant administration of the vaccines was demonstrated to be noninferior to nonconcomitant administration. Concomitant administration was generally well-tolerated. No participants withdrew because of an AE. One serious AE of transient muscular weakness of <24 hours' duration after the third Gardasil injection was reported in group B and was deemed possibly vaccine-related by the investigator.

CONCLUSIONS: Overall, concomitant administration was generally well-tolerated and did not interfere with the immune response to the respective vaccines. Concomitant administration should minimize the number of visits required to deliver each vaccine individually, leading to increased compliance and more effective disease prevention.