Vaccine Study in South Africa Achieves Significant Reductions in Pneumonia
Pneumococcal Vaccine Could Prevent Leading Worldwide Cause of Childhood
In a recent
clinical trial conducted in 40,000 children in Soweto, South Africa,
scientists from Emory University and the University of Witwatersrand
found that a new version of a pneumococcal vaccine reduced the
incidence of pneumonia in vaccinated children by more than 20%. In addition,
the vaccine reduced the incidence of invasive pneumococcal disease
pneumococcal bacteria that can be measured in the bloodstream
by more than 80% in these children not infected with the HIV virus
and by more than 50% in HIV-infected children.
The study was conducted under
the auspices of the World Health Organization (WHO) and the Medical
Research Council of South Africa in collaboration with Wyeth Pharmaceuticals,
which developed the vaccine. Keith P. Klugman, M.D., professor of international
health in Emory's Rollins School of Public Health and professor of medicine
in Emory School of Medicine, was principal investigator of the study.
He presents the results at the 3rd International Symposium on Pneumococci
and Pneumococcal Diseases in Anchorage, Alaska.
According to the WHO, pneumonia
is the leading cause of death in children worldwide and is responsible
for approximately four million deaths a year. Most of these deaths occur
in developing countries. Although pneumonia has many different causes,
the pneumococcus bacterium is the primary cause. Until recently,
no vaccine was available to prevent pneumococcal disease in young
children. In addition to pneumonia, pneumococcus can cause meningitis,
ear infections and sinusitis.
"With this reduction in the
incidence of pneumonia, we could potentially save over 500,000 lives
each year in the developing world," said Dr. Klugman. "In addition,
no vaccine has previously been documented to prevent pneumococcal
disease in HIV-infected children, and our study showed a 50% reduction
in this group. In an era in which there is little to offer to children
with HIV, we can clearly reduce invasive disease."
A vaccine to prevent pneumoccocal
disease, also developed by Wyeth Pharmaceuticals, is now indicated for
all U.S. children to prevent invasive pneumococcal disease and
bacterial meningitis, and is administered in infancy. The vaccine targets
7 strains of pneumococcal disease, but its impact on pneumonia in developing
countries was heretofore unknown. The vaccine used in South Africa includes
two additional strains of pneumococcus that are prevalent in
The clinical trial randomized
two groups of infants to receive either three doses of vaccine or placebo.
The scientists tracked the vaccine's effectiveness over a four-year
period through active surveillance of children with pneumococcal
disease at the large academic hospital serving the community of Soweto,