Vaccinating infants against five diseases in one shot works just as well as separate injections, with no higher rate of side effects, Italian investigators report.

The five-in-one vaccine the team studied combined an existing four-in-one vaccine - against diphtheria, tetanus, whooping cough and Hepatitis B (DTaP-HBV) - with the Haemophilus influenzae type b (Hib) vaccine.

Relatively few infants in Italy get three doses of Hib vaccine as they should, Dr. G. Gabutti, from the University of Ferrara, and colleagues point out in the journal Clinical Drug Investigations.

They suggest that combining Hib vaccine with the DTaP-HBV vaccine would simplify the injection schedule and promote better compliance with Hib vaccination.

To be sure that such an approach produces a protective immune rsponses and does not cause undue reactions, the group recruited 360 healthy infants ages 12 to 16 weeks for a trial. The babies were assigned to get injections of either the combined vaccine or separate DTaP-HBV and Hib vaccines. Vaccinations were administered at ages 3, 5 and 11 months.

Following completion of the three-dose vaccination course, more than 97 percent of both groups had protective levels of antibodies against Hib, diphtheria, tetanus, pertussis and Hepatitis B.

“Combining the two vaccines did not affect the high level of protection afforded by separate administration of the vaccines,” Gabutti’s team writes.

Side effects were usually mild and transient, resolved without any ongoing problem, and were no more common in the combined-vaccine group than the separate-vaccines group.

SOURCE: Clinical Drug Investigations, May 2005.