Clinical

Jury out on added benefit of combined DTP-HBV-HIB vaccine

Last Updated: 2009-08-05 13:30:35 -0400 (Reuters Health)

NEW YORK (Reuters Health) - It is unclear whether the combined diphtheria-tetanus-pertussis, hepatitis B, and Haemophilus influenzae type B (DTP-HBV-HIB) vaccine is as effective as the separate DTP-HBV and HIB vaccine, researchers say.

Based on the pooled results of 18 studies, "We could not conclude that the immune responses elicited by the combined vaccine were different from, or equivalent to, the separate vaccines," the researchers wrote in the July 8 issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research.

The World Health Organization recommends that routine infant vaccination programs use the combined DTP-HBV-HIB vaccine, yet the effectiveness and safety of adding a conjugate HIB vaccination to the DTP-HBV vaccine, compared with separate administrations, has yet to be systematically assessed, the authors note.

To investigate, Dr. Edna Bar-On, of Rabin Medical Center in Petah-Tiqva, Israel and colleagues and performed a meta-analysis of 18 randomized or quasi-randomized clinical trials involving a total of 10,374 children. The studies compared vaccination of any combined DTP-HBV-HIB vaccine with or without three types of inactivated poliovirus or concomitant oral polio vaccine compared with separate vaccines or placebo, administered to infants aged up to 2 years.

According to the investigators, there were no data on the primary outcome (prevention of disease); all of the studies used reactogenicity (adverse events) and immunogenicity.

With the combined vaccine, they found some evidence of lower immune responses for HIB and HBV, and more local adverse reactions, although "these differences rely mostly on one study each," they caution.

The reviewed studies "did not use an intention-to-treat analysis and we were uncertain about the risk of bias in many of the studies," Dr. Bar-On and colleagues add. "These results are therefore inconclusive."

There were no significant differences in immunogenicity for pertussis, diphtheria, polio and tetanus. Serious adverse events were comparable between the vaccines, while minor adverse events were more common with the combined vaccine.

Cochrane Database Syst Rev 2009.