In a breakthrough for the fight against meningitis in poor countries, researchers say the WHO has ruled that a key vaccine can be transported or stored for up to four days without refrigeration.
The previously-approved vaccine is aimed at helping in the so-called "Meningitis Belt," which stretches across the African Sahel from Senegal to Ethiopia, where epidemics of the deadly infection regularly break out.
In these countries, where reliable electricity is rare, especially in rural areas, assuring that the low-cost vaccine can be stored safely without refrigeration will vastly improve vaccination campaigns, researchers say.
Called MenAfriVac and made by the Indian company Serum Institute, the vaccine costs less than 50 cents a dose and, according to the latest research, can be conserved without any refrigeration, even an icepack, at temperatures up to 104 degrees Fahrenheit (40 degrees Celsius) for four days.
"Reaching the millions of children in last mile communities like those in rural Africa continues to challenge us," said Dr. Orin Levine, director of vaccine delivery at the Bill & Melinda Gates Foundation.
"The potential for some vaccines to remain safely outside the cold chain for short periods of time has been widely known for over 20 years," said Michel Zaffran, director of a nonprofit collaboration with the WHO aimed at improving immunization systems and technologies.
"We expect this announcement to build momentum" for testing other vaccines for storage without refrigeration, he said.
The findings, from a study of the vaccine carried out by Health Canada and confirmed by the World Health Organization Vaccines Pre-Qualification Program and the Drugs Controller General of India—were unveiled Wednesday at a conference in Atlanta.
Other research presented there showed that the vaccine has been effective in reducing meningitis A in Burkina Faso, the first country to introduce the vaccine, in 2010.
Just two years later, the bacteria that causes meningitis A had been eliminated, not only in those who received the vaccine, but in others around them, said Marie-Pierre Preziosi, director of the Meningitis Vaccine Project.
"Our findings show that the bacteria causing meningitis A have disappeared from the noses and throats of those too old or too young to have received the vaccine, resulting from a phenomenon known as 'herd immunity,'" she said.
"And we can also show that after introduction in Burkina Faso, we saw the lowest level of epidemic meningitis in 15 years," added Preziosi, the lead author of the study, which will appear in Clinical Infection Diseases.
Meningitis A is a bacterial infection that affects the membrane of the brain.
It can cause brain lesions and has a 50 percent fatality rate when left untreated, according to the WHO.
Viral meningitis is generally less severe, with most patients fully recovering on their own within a week or two.