The stand-alone diphtheria, tetanus, acellular, pertussis and inactivated poliovirus combination vaccine – DTaP5-IPV – is equivalent as a fifth dose to the separate DTaP5 plus IPV vaccines in children aged 4-6 years, according to a noninferiority study.

In a phase III, controlled, open-label study, 3,372 children who had completed the 4-dose infant/toddler vaccination were randomized to DTaP5-IPV plus MMR and varicella virus (VZV) vaccines, DTaP5+IPV with MMR and VZV, DTaP5-IPV with/without MMR/VZV, or DTaP5+IPV with/without MMR/VZV.

Michael J. Smith, MD , MSCE, of the University of Louisville (Ky.) and coauthors saw significantly higher pertussis antibody levels for all antigens in the group who received the DTaP5-IPV plus MMR and VZV vaccines than in the group who received the DTaP5+IPV with MMR and VZV. Twenty-eight days after the vaccine was given, booster responses ranged from 95% to 97% for the DTaP5-IPV group and from 87% to 93% in the DTaP5+IPV group.

Similarly, the DTaP5-IPV vaccine showed noninferiority in the booster response for antitetanus, antidiphtheria, and antipoliovirus antibody levels ( Pediatr Infect Dis J. 2017 Mar;36[3]:319-25 ).

“Overall, the levels of immune responses described in both treatment groups in the current study are above the levels described in the Swedish infant efficacy study, which demonstrated 85% protective efficacy against World Health Organization–defined pertussis disease,” the authors wrote. “Thus, it is reasonable to conclude that protective efficacy against pertussis will be achieved when either DTaP5-IPV or DTaP5+IPV is given as a booster dose to children 4-6 years of age.”

The two vaccines showed a similar safety profile. The rate of immediate, unsolicited, adverse systemic events was 0.9% in the DTaP5-IPV group and 1% in the DTaP5+IPV group, while the rate of immediate, unsolicited, adverse reactions was 0.1% in the DTaP5-IPV group and 0.2% in the DTaP5+IPV group.

Solicited reactions also were similar between the two groups: 93% of participants who received DTaP5-IPV and 92% of those who received DTaP5+IPV reported reactions such as myalgia, malaise, pain, erythema, and change in limb circumference.

“This is consistent with the established safety profile of DTaP5+IPV vaccine, based on 16 years of postmarketing surveillance and more than 7 million doses distributed,” the authors wrote.

There were also three serious adverse events in the DTaP5-IPV group within 28 days of the vaccination – lobular pneumonia, asthma, and new-onset type 1 diabetes mellitus – but the investigator decided these were unrelated to vaccination.

The study was sponsored by Sanofi Pasteur, which manufactures both vaccines. Three authors were employees of Sanofi Pasteur, and one author declared funding from Sanofi Pasteur to present the study results at a meeting.