Regulatory authorities have relaxed temperature controls on a meningitis vaccine, allowing it to be transported for several days without refrigeration, a move that could lower its price for use in Africa. It is the first such approval for a vaccine on the continent.
MenAfriVac is made in India and used in 26 countries in Africa to protect against meningitis A. The Drug Controller General of India and the WHO have now approved the vaccine's supply in a controlled temperature chain at up to 40 degrees Celsius for as long as four days.
Benin is the first country to deploy the vaccine in a less stringent temperature chain, in a pilot programme running from 15-25 November in the north of the country.
Manufacturing and delivering MenAfriVac costs about 75 US cents per dose, and storing it outside a cold supply chain could cut the price by about ten cents, says Michel Zaffran, director of Optimize, a PATH-WHO collaboration to improve vaccine technology and systems.
"Some countries such as Chad have a very poor cold chain infrastructure. They have to bring in fridges and diesel generators and then pull everything back to the capital when the vaccination programme is finished. This [new approval] will be a big help," he says.
Zaffran says he hopes MenAfriVac is the first of many vaccines to be relicensed in this way and that manufacturers will look at building heat stability tests into clinical trials.
"It has taken a long time to get a few manufacturers to realise the importance of this and we hope that others will look at stability data and whether their vaccines can be relicensed. We hope, too, that the announcement of the first vaccine will be an additional incentive to manufacturers," he says.
There is already good data on heat stability for yellow fever and human papillomavirus vaccines. But some may need to undergo more clinical trials, Zaffran adds.
But there is potential for confusion, he says.
"In principle all vaccines are more heat-stable than indicated on their label. But the recommendation to keep all vaccines between two and eight degrees Celsius is a simple, straightforward recommendation that can be deployed everywhere. If you say 'this vaccine is more stable' it gets confusing."
He says that as vaccine programmes are becoming more sophisticated, this will be less of an issue.
Anthony Battersby, a consultant who has implemented vaccination programmes for organisations including the WHO, says that being able to keep a vaccine out of the cold chain is a major breakthrough - but for many vaccines it would not be possible.
The main risk is that the vaccine would not work, not that it would be harmful, he says.
"There is always research going on into how to get more stable vaccines but any research into vaccines is extremely expensive and long - it takes years to do," Battersby says.