Hib Vaccine Prevents Pneumonia and Meningitis in Asia

Hib Infection More Prevalent in Asia Then Previously Suspected

Haemophilus influenzae type b bacteria (Hib) vaccination provided protection against either pneumonia or meningitis to the one out of every 33 children who received the vaccine, according to the results of a multi-center study in Indonesia that included researchers from Johns Hopkins Bloomberg School of Public Health. The study, the largest Hib evaluation ever conducted in Asia, indicated that Hib infection is more prevalent in Asia than previously suspected and that wide-spread use of the vaccine could be beneficial, given the high number of deaths from meningitis in the region. The findings appear in the January 1, 2005, edition of The Lancet.

Routine vaccination has virtually eliminated Hib infections in most developed countries. However, many Asian nations do not include Hib vaccine as part of childhood immunizations. It is estimated that 350,000 to 750,000 children die from Hib-related pneumonia and meningitis each year and another 3 million become seriously ill from the bacteria.

“Because there are limited reports of Hib disease in Asia, many scientists believe the infection is not important in that region,” said study co-authorMark Steinhoff, MD, professor in theDepartment of International Health at the Bloomberg School of Public Health. “This project is unique in that, for the first time, a vaccine known to be safe and effective was used to estimate the amount of disease caused by a specific bacterium. Since the Hib vaccine prevents only Hib disease, any difference between the vaccinated and unvaccinated groups can be attributed to Hib vaccine. This study shows the overall effect of Hib vaccine on the health of children,” explained Dr. Steinhoff.

The study enrolled and immunized 55,000 infants from communities throughout Lombok island in Indonesia over a two year period. Each community was randomly selected to receive either the diphtheria, tetanus and pertussis (DTP) vaccine with added Hib antigen, or the standard DTP vaccine.

The study showed that Hib vaccine prevented many more cases of meningitis, than older estimates had predicted. The researchers noted that the vaccine only prevented about 4 percent of pneumonia cases that could be verified by a chest X-ray, which was a smaller amount than expected. 

“The study strengthens the case that Hib vaccine should be used in Asia and should become part of routine immunization in this part of the world,” said co-author Lawrence H. Moulton, PhD, professor of International Health at the Bloomberg School. “We’ve shown that Hib disease is present and important, and that Hib vaccine prevents substantial numbers of illness episodes. Since Hib disease has been eliminated by vaccine from virtually all countries in North and South America, Europe and Australia, and some African countries have adopted the vaccine, Asia is the only remaining part of the world that is not routinely using Hib vaccine to protect children.” 

“Incidences of vaccine-preventable Haemophilus influenzae type b pneumonia and meningitis in Indonesian children: hamlet-randomised vaccine-probe trial” was written by Bradford D. Gessner, Augustinus Sutanto, Mary Linehan, I Gusti Gede Djelantik, Tracy Fletcher, I Komang Gerudug, Ingerani, David Mercer, Vanda Moniaga, Lawrence H. Moulton, Kim Mulholland, Carib Nelson, Soewignjo Soemohardjo, Mark Steinhoff, Anton Widjaya, Philippe Stoeckel, James Maynard and Soemarjati Arjoso.

The study was funded by grants from the Office of Health and Nutrition of the U.S. Agency for International Development and the Children’s Vaccine Program. Additional funding and vaccine were supplied by Aventis Pasteur.