First major randomized, controlled vaccine clinical trial in nearly 20 years to show significant reduction in child mortality
Washington, DC, 25 March 2005 - Global health leaders today presented new research showing that vaccinating infants against Streptococcus pneumoniae - a bacterium that causes deadly pneumonia, meningitis and sepsis - could substantially reduce death and serious illness among children in the developing world. If used widely, a pneumococcal conjugate vaccine could prevent hundreds of thousands of child deaths each year.
In a four-year study a team led by the UK Medical Research Council's Felicity Cutts vaccinated and followed over 17,000 young children in the Gambia to study whether a vaccine that has been shown to prevent pneumococcal disease in the United States, Finland and urban South Africa would also work in rural Africa. The results, to be published in the March 26 issue of The Lancet show that the vaccine reduced childhood mortality by 16 percent in children who received the pneumococcal conjugate vaccine. This study is the first major randomized, controlled vaccine clinical trial in nearly twenty years to show a statistically significant reduction in overall child mortality.
"The results of this vaccine trial hold great promise for improving health and saving lives in resource-poor populations, said Dr. Lee Jong-wook, the Director-General of the World Health Organization (WHO). "The international community's task now is to continue to work together productively to make the pneumococcal conjugate vaccine widely available to children in Africa, as lives are lost every minute to pneumococcal disease. Immunizing children with pneumococcal conjugate vaccine in developing countries will be a critical intervention towards achieving a two-thirds reduction in the under-five mortality rate, a Millennium Development Goal."
Streptococcus pneumoniae, or pneumococcus, is the bacterium that causes pneumococcal disease. When they invade the lungs, these bacteria cause the most common kind of bacterial pneumonia and can then invade the bloodstream (bacteremia) or the tissues and fluids surrounding the brain and spinal cord (meningitis). According to WHO, pneumococcal pneumonia and meningitis are responsible for about 1.6 million deaths each year, even more than malaria. And more than 90 percent of pneumococcal pneumonia deaths in children occur in developing countries.
Previous studies had shown that this vaccine was effective in reducing the number of pneumococcal infections in children in the United States, Finland and in urban South Africa. But many of the children suffering from pneumococcal disease in Africa live in rural areas with high infant mortality rates, significant rates of malaria transmission and very limited access to healthcare. The Gambia is representative of these areas, and the results of the study suggest that the deaths caused by pneumococcal infections in rural Africa are preventable. "The trial results are highly positive and promising, and most importantly, they demonstrate that pneumococcal vaccination can prevent these serious infections even in a rural African setting," said Professor Cutts.
Sponsors of and participants in this successful trial included the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health; the World Health Organization (WHO); PATH's Children's Vaccine Program (CVP); the U.S. Agency for International Development; Johns Hopkins Bloomberg School of Public Health and the Centers for Disease Control and Prevention. Wyeth Pharmaceuticals provided the trial vaccine.
Summary of trial results
In this trial:
- This vaccine significantly reduced the need for hospitalization: children receiving the pneumococcal vaccine had 15 percent fewer hospital admissions than those who did not.
- The nine-valent pneumococcal conjugate vaccine was 77 percent effective in preventing pneumococcal infections caused by the vaccine serotypes.
- As a result, there were 37 percent fewer cases of pneumonia in the children who received the vaccine compared with children who received the control vaccine.
Working with the Global Alliance for Vaccines and Immunization (GAVI), Wyeth Pharmaceuticals has offered to provide the pneumococcal conjugate vaccine Prevnar to The Gambia for introduction into their national immunization program. Wyeth is also working with GAVI's PneumoADIP and other public health partners to facilitate access to Prevnar and future pneumococcal conjugate vaccines with expanded serotype coverage to children in developing countries.