More evidence Gardasil, Menactra, and Adacel can be given together

By Reuters Staff

NEW YORK (Reuters Health) - Coadministration of the 9-valent human papillomavirus (9vHPV) vaccine (Gardasil) with the quadrivalent meningitis vaccine (MCV4, Menactra) and diphtheria/tetanus/acellular pertussis vaccine (Tdap, Adacel) is safe, effective, and convenient, new research confirms.

"Concomitant administration of 9vHPV vaccine with MCV4/Tdap was generally well tolerated and did not interfere with the antibody response to any of these vaccines. This strategy would minimize the number of visits required to deliver each vaccine individually," the researchers report online August 3 in Pediatrics.

Dr Andrea Schilling, from Facultad de Medicina Clinica Alemana-Universidad del Desarrollo, Santiago, Chile, and colleagues say their findings support a study published in Pediatrics in 2010 (http://bit.ly/1IjQdID) which showed that Gardasil, Menactra, and Adacel can be safely and effectively given at the same time. (See Reuters Health story, May 4, 2010).

Participants in their study included 1,241 boys and girls aged 11 to 15 years old. All received 9vHPV vaccine on day one and two and six months later; 621 subjects received MCV4/Tdap concomitantly with 9vHPV vaccine on day one, while the remainder received MCV4/Tdap one month later.

"This study demonstrated that when the first dose of 9vHPV vaccine is administered concomitantly with MCV4 and Tdap at a separate injection site, the immune response to all vaccine components is noninferior to the immune response achieved when the three vaccines are administered nonconcomitantly," the authors report.

Specifically, geometric mean titers to all nine vaccine HPV types were "noninferior" in the concomitant group compared with the nonconcomitant group and all adolescents in both groups seroconverted after the third dose of 9vHPV vaccine. Also, antibody responses to components of Menactra and Adacel at four weeks after administration were also similar in the two groups.

Concomitant administration of the first dose of 9vHPV vaccine with Menactra and Adacel was "generally well tolerated," with no marked differences in adverse events.

The chief limitation of the study is its unblinded nature, the researchers say. Another is that the coadministration of Menactra and Adacel was assessed only with the first dose of HPV vaccine. It's also hard to know whether the results obtained in this study can be extrapolated to other meningococcal vaccines, they say.

"Providing vaccinations to adolescents is challenging because they make infrequent health care visits. Concomitant administration would minimize the number of visits required to deliver each vaccine individually and therefore facilitate adherence to recommended vaccination regimens," Dr. Schilling and colleagues note in their paper.

"In the United States, coverage for the first dose of HPV vaccine remains substantially lower (by roughly 20-25 percentage points) than coverage for other vaccines recommended by the Advisory Committee on Immunization Practices for children 11 to 12 years of age. It is estimated that coadministration of HPV vaccine with other vaccines such as diphtheria, tetanus, pertussis, meningococcal conjugate, and influenza vaccines could increase coverage for the first dose of HPV vaccine to >90%," they add.

Dr. Schilling did not respond to a request for comment by press time.

The study was supported by Merck, which makes Gardasil. Several authors disclosed relationships with the company and three authors are employees of the company.

SOURCE: http://bit.ly/1HlBR95

Pediatrics 2015.

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