New meningitis vaccine for Africa could signal end to deadly scourge

The Meningitis Vaccine Project (MVP) released new data on the performance of a vaccine in West African children, suggesting that the new vaccine — expected to sell initially for 40 US cents a dose — will be more effective in protecting African children and their communities than any vaccine currently on the market.

MVP, a partnership between the World Health Organization (WHO) and the Seattle-based nonprofit, PATH, is collaborating with a vaccine producer, Serum Institute of India Limited (SIIL), to produce the new vaccine against serogroup A Neisseria meningitidis (meningococcus).

The preliminary results of their study, a Phase 2 vaccine trial, reveal that the vaccine could eventually slash the incidence of epidemics in the “meningitis belt,” as 21 affected nations of sub-Saharan Africa are collectively known. The vaccine is expected to block infection by the serogroup A meningococcus, and therefore extend protection to the entire population, including the unvaccinated, a phenomenon know as “herd immunity.” 

“When it becomes part of the public health arsenal, this vaccine will make a real difference in Africa,” said Dr. F. Marc LaForce, MVP director. “The vaccine will allow elimination of the meningococcal epidemics that have afflicted the continent for more than 100 years.”

The new meningococcal conjugate vaccine trial, in 12- to 23-month-olds in Mali and the Gambia, shows that the vaccine was safe, and that it produced antibody levels almost 20 times higher than those obtained with the marketed polysaccharide (un-conjugated) vaccine. This means that protection from serogroup A meningococcal meningitis is expected to last for several years.

“This important study brings real hope that the lives of thousands of children, teenagers, and young adults will be saved by immunization and that widespread suffering, sickness and socioeconomic disruption can be avoided,” said Dr. Margaret Chan, Director-General of the World Health Organization.

“Elimination of these epidemics with wide use of the meningococcal A conjugate vaccine is now a likely possibility over the next few years,” said LaForce.

“People between the ages of 1 and 29 years of age will be protected by receiving a single dose in large mass vaccination campaigns. The large campaigns are expected to create herd immunity, and eventually, elimination of the disease.”

As a result of the encouraging preliminary findings of this Phase 2 clinical study, SIIL and MVP will proceed with a Phase 2/3 study where the vaccine will be tested in 2- to 29-year-olds — the population that will be mostly targeted by mass vaccination campaigns. Testing will take place in Mali, the Gambia, and at least one other African country. An additional clinical study is planned for this summer in India, where the vaccine will be licensed.

A conjugate vaccine joins (or “conjugates”) sugars from the meningococcal bacterium with a protein, which in turn stimulates immune cells. These cells then produce antibodies to meningitis, protecting the individual from infection. A total of 600 toddlers participated in the Phase 2 study.

“The plans for the future are quite ambitious,” said LaForce. “With the successful completion of the Phase 2 study, and once funding is secured, we plan to do a demonstration study next year in a  hyperendemic country where we will take the vaccine to public-health scale by immunizing the entire population between the ages of 1 and 29. If all continues to go well in testing and during the demonstration study, the new vaccine, which will be priced at about 40 cents per dose, could be introduced in Africa within the next two to three years.”

Meningitis is an infection of the meninges, the thin lining that surrounds the brain and spinal cord. It is one of the world’s most dreaded infectious diseases. Even with antibiotic treatment, at least 10% of patients die, with up to 20% left with permanent problems, such as mental retardation, deafness, epilepsy, or necrosis leading to limb amputation.