Coadministration of Gardasil With Menactra, Adacel May Be Safe, Immunogenic

Laurie Barclay, MD

May 17, 2010

May 17, 2010 — Coadministration of Gardasil (human papillomavirus [HPV] vaccine), Menactra (meningitis vaccine), and Adacel (diphtheria-pertussis-tetanus vaccine) vaccines does not reduce the safety, tolerability, and immunogenicity of these individual vaccines, according to the results of an open-label study reported online May 3 in Pediatrics.

These vaccines are currently recommended by the Advisory Committee on Immunization Practices (ACIP) for routine vaccination of adolescents.

When asked for independent comment by Medscape Pediatrics, Lauri Markowitz, MD, said, "This study supports current ACIP recommendations that HPV vaccine can be administered with other vaccines that are recommended for adolescents."

She also added, "Concomitant administration of vaccines can minimize the number of visits required to deliver each vaccine and lead to increased compliance."

Dr. Markowitz is a medical epidemiologist from the Epidemiology and Surveillance Branch/Division of STD Prevention/National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention in Atlanta, Georgia.

On the basis of findings from multinational, phase 3 trials, Gardasil appears to be generally effective, immunogenic, and well tolerated. The purpose of this study, by Keith S. Reisinger, MD, MPH, from Primary Physicians Research in Pittsburgh, Pennsylvania, and colleagues, was to determine the immunogenicity and safety of Gardasil administered concomitantly with Menactra and Adacel.

In a 1:1 ratio, 394 boys and 648 girls aged 10 to 17 years were randomly assigned to group A (concomitant administration) or group B (nonconcomitant administration). Group A received 0.5-mL Gardasil at day 1, month 2, and month 6 and a 0.5-mL dose of Menactra and Adacel on day 1, whereas group B received Gardasil at day 1, month 2, and month 6 and Menactra and Adacel at month 1. The investigators measured antibody levels for all vaccine components and monitored systemic, injection-site, and serious adverse experiences (AEs).

After concomitant administration of the 3 vaccines, immune responses were noninferior to those seen after nonconcomitant administration. In both groups A and B, seroconversion for Gardasil was at least 99%. Concomitant administration of Menactra and Adacel vaccines was shown to be noninferior to nonconcomitant administration.

In general, concomitant administration was well tolerated, and no study participants withdrew because of an AE. In group B, there was 1 serious AE of transient muscular weakness after the third Gardasil injection. This AE lasted less than 24 hours and was judged by the investigator to be possibly vaccine related.

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

When asked about the main strengths and limitations of this study, Dr. Markowitz noted that this was a "randomized trial of adolescent males and females in the target age group for HPV vaccine in the US, evaluating HPV vaccine with and without concomitant administration of other vaccines recommended for adolescents."

Limitations noted by the study authors included unblinded design and possible overestimation of reporting of AEs in the concomitant vaccination group. Because of the incorrect administration of Menactra and Adacel in 2 different limbs in group B (n = 92), the number of participants in the nonconcomitant group was lower than the number in the concomitant group in the analyses of specific injection-site AEs.

"Co-administration of Gardasil, Menactra, and Adacel does not compromise the safety, tolerability, and immunogenicity of the individual vaccines," the study authors conclude.

"The inclusion of Gardasil in the adolescent vaccination schedule provides an opportunity for physicians to co-administer other recommended vaccines with the ultimate goal of increased compliance, enhanced implementation, and disease prevention."

Merck Research Laboratories, a Division of Merck & Co, Inc, and maker of Gardasil, supported this study and employs 5 of the study authors. Some of the other study authors have disclosed various financial relationships with Merck & Co, Inc; GlaxoSmithKline; Novartis; Sanofi-Pasteur MSD, the maker of Menactra and Adacel; and/or MedImmune.

Dr. Markowitz has disclosed no relevant financial relationships.

Pediatrics. Published online May 3, 2010. Abstract


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