1. Simultaneous administration of the 9-valent human papillomavirus (HPV) vaccine with Tdap (tetanus/diphtheria/acellular pertussis) and Menactra (Neisseria meningitidis) resulted in a noninferior antibody response compared to non-simultaneous injections.
2. There was no statistical difference in vaccine-related serious adverse events between the two groups, although concomitant injection did result in more frequent injection site swelling.
Evidence Rating Level: 2 (Good)
Study Rundown: Vaccine schedules emphasize concomitant administration whenever possible to increase adherence and decrease cost. Based on previous clinical studies, the 9-valent HPV vaccine (9vHPV) has been proven effective in preventing disease for boys and girls age 9 through 26 years. The median age of sexual debut is 15 to 19 years and HPV is acquired soon after the onset of sexual activity, therefore early adolescence is the ideal time for vaccination. Equally important at that time are Tdap and Menactra vaccines. As such, this study sought to evaluate the efficacy of concomitant vaccination with 9vHPV and Tdap/Menactra compared to staggered administration in the theoretically ideal population. Two groups of 11 to 15 year-old children were randomized to receive 9vHPV along with Tdap and Menactra (concomitant) or 9vHPV 1 month prior (staggered). Blood samples were used to determine the immune response to the vaccines over time. Overall, the concomitant group had a noninferior response to all 3 vaccines, compared to the staggered group. No serious adverse events occurred in either group, although there was greater injection site swelling in the concomitant injection group. Clinicians may expect future changes to vaccine schedules that reflect these results, ideally leading towards greater HPV vaccine coverage while lowering cost. While this study adds to the evidence that concomitant vaccination is safe and effective, it is limited by the lack of long-term follow up.
In-Depth [prospective cohort study]: This study recruited 1237 boys and girls, ages 11 through 15 years who had not achieved sexual debut, from 41 sites in South, Central, and North America. Subjects were randomly assigned to the concomitant group, who received 9vHPV, Tdap, and Menactra vaccines all on day 1, or the nonconcomitant group, who received 9vHPV on day 1 and Tdap and Menactra 1 month later. Both groups also received 9vHPV at months 2 and 6 to complete the series. To measure immune response, blood samples were collected before vaccination, on day 1, and at months 1, 2 (noncomitant group only), and 7. Blood was analyzed for geometric mean titres (GMTs) of all expected antibodies in both groups. GMTs for each component were compared between both groups. In month 7, the anti-HPV response rate was 100% for all serotypes in both groups. The estimated percentage point difference in response to N. meningitidis serotypes was 3.8% for type A and 2.1% for types C, W-135, and Y. Diphtheria response was 100% in both groups. Percent difference between responses to tetanus was 0.2% (99.8% in concomitant vs. 100% in nonconcomitant). The concomitant group reported significantly more swelling at the injection site after the first injection, compared to the nonconcomitant group, though the majority of cases were mild to moderate.
©2015 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.