A new vaccine promises to combat the scourge of meningitis in Africa. It has passed its first major testing hurdle in India with very good results.
The world is blanketed with disease organisms called meningococcal bacteria. They cause a variety of common mild ailments like ear and blood infections. But they also induce life-threatening ones like meningitis, an inflammation of the thin layer of fluid that surrounds the brain and spinal cord.
Meningitis vaccines exist, but they do not provide long lasting protection and are not very effective in children. The U.S. government's drug regulating agency, the Food and Drug Administration, created a new vaccine to overcome those problems. A version for the meningitis strain that afflicts sub-Saharan Africa is in the testing phase.
"The vaccine is important because of the repeated epidemics of meningococcal meningitis that sweep across sub-Saharan Africa," said Physician Marc LaForce.
Mr. LaForce directs the program that is developing the new vaccine, the Meningitis Vaccine Project. It is a partnership between the World Health Organization (WHO), a U.S. non-profit group in Seattle called the Program for Appropriate Technology in Health, and the Serum Institute of India, a drug maker.
"Annually there are small epidemics throughout the meningitis belt, but about every 10 or 12 years, there are these major epidemics that cause literally tens of thousands of cases," he explained. "The last epidemic was in 1996-1997, with over 180,000 cases with 20,000 deaths."
The meningitis belt ranges from Senegal and Gambia in West Africa to Ethiopia in the east. At risk are about 430 million people.
Antibiotics help against the disease, but at least 10 percent of patients die. As many and even more are left with permanent problems such as mental retardation, deafness, and epilepsy.
That raises the importance of vaccines to prevent meningitis. A vaccine works by introducing bits of disease into the body to train immune system cells how to attack when the germ invades on its own. But available meningitis vaccines usually do not work in infants and children, who are the bulk of meningitis patients, because parts of their immune system are too immature to react. To get around this, project scientists added a tetanus protein to the new vaccine that is recognized by better-developed segments of young children's immune system.
Dr. LaForce says the vaccine performed well in recently completed clinical trials in the Indian cities Hyderabad and Bombay, also known as Mumbai.
"The results met every one of our expectations," he said. "The vaccine was safe and, very importantly, the immune response in infants and toddlers was good."
Unlike the existing meningitis vaccine, which protects only those inoculated, the experimental one blocks transmission of the disease in a population, so people who have not been immunized are also protected.
The next phase of tests is being planned for Africa. LaForce predicts that if it goes well, the vaccine could be available on the continent in three or four years at the very low cost of $0.40 per dose.
He says the Serum Institute of India agreed to that price after the Meningitis Vaccine Project conferred with African health and finance ministries about what they could afford.
"We were told that if we were able to develop a vaccine at less than $0.50 a dose, this would be a product that could be folded in to the general health budgets in these countries and would virtually guarantee sustainability once the vaccine was introduced," he added.
LaForce says he believes that the new meningitis vaccine will reduce the incidence of the disease by a third to a half in countries where it is used following testing.