DAKAR — For decades, distribution of vaccines in Africa and other warm regions has been hampered by the need to keep the vaccines refrigerated - a major challenge in remote areas without electric power. But the World Health Organization says a new vaccine aimed at preventing meningitis A can withstand temperatures up to 40 degrees Celsius, and was found to be 100 percent effective during a trial study in Benin.
Researchers said that health workers in Benin have successfully immunized more than 155,000 people against meningitis A using the first vaccination to be approved for use without constant refrigeration, also known as the "cold chain."
The World Health Organization (WHO) said the vaccine, which is known as MenAfriVac, can be stored for up to four days in temperatures up to 40 degrees Celsius.
PATH is a U.S.-based non-profit organization that partnered with the WHO on the Meningitis Vaccine Project. Dr. Marie-Pierre Preziosi, the project's director, said the new breakthrough could revolutionize the way vaccination campaigns are conducted in developing countries. She spoke to VOA from Ouagadougou.
“As you know, vaccines are usually kept in cold chains, between 2 to 8 degrees Celsius. And so you have to have the whole capacity around the cold chain: that is freezers, ice packs, transportation fuel, electricity fuel, all of this. Sometimes, it is not only costly, but it is also very challenging to reach remote areas with such constraints,” said Preziosi.
Health experts said that because of the cold chain requirement, there is normally a lot of wasted vaccine vials during immunization campaigns, particularly during the “last mile” -- the time from when the vaccine leaves the refrigerator at the district health center until it is injected into a person’s arm at the village level.
Many communities in Africa have no access to electricity and are often too remote to be reached before the ice packs in insulated coolers melt.
Preziosi said the flexibility of being able to transport the vaccine outside of the cold chain meant that only nine vaccine vials out of 15,000 had to be discarded during the trial study in Benin.
Being able to work outside the cold chain also meant that health workers didn’t have to travel to and from the district health center each day to replenish vaccine supplies. This allowed them to vaccinate more people in a shorter amount of time.
PATH’s vice president for product development, Dr. David Kaslow, said that removing the refrigeration requirement for MenAfriVac could also reduce costs.
“The one study that was done with the WHO looked at the modeled scenario, which is: what are all the costs that are incurred in that last mile? And really, one of the major costs, obviously, are the cold chain costs themselves… And so the analysis was done as to what is the cost savings. And it’s about 50 percent," he noted. "On average, from 24 cents per dose delivered to 12 cents per dose delivered.”
Meningitis, which is the inflammation of the protective tissue that covers the brain and spinal cord, can lead to severe brain damage if left untreated and results in death in about 50 percent of cases.
The WHO said that while meningitis can be prevented with vaccines, more than one million suspected cases have been reported by countries in Africa’s "meningitis belt" over the past 20 years.
The Meningitis Vaccine Project said that following the MenAfriVac vaccination campaign in Benin, there were no reported cases of Meningitis A in any of the 150 vaccinated communities.
Kaslow said that it is now up to individual countries to take advantage of this success and allow health workers to use MenAfriVac within the new temperature conditions.
He said the next step will be for pharmaceutical developers to see if the refrigeration requirements for other vaccines, such as cholera, can also be changed.