Scientists at PATH, the Seattle-based nonprofit that works to improve health in poor countries, have found a cheap and simple way to tackle one of the vexing challenges of global health: how to keep vaccines from going bad when they get either too hot or too cold.
PATH scientists, with help from collaborators at U.K-based Arecor and University of Colorado, said they were able to develop a new formulation of hepatitis B vaccine that was able to withstand temperatures as high as 37 degrees Celsius (98.6 degrees Fahrenheit) for a year’s worth of shelf life, while also remaining stable at temperatures as cold as -20 degrees Celsius (-4 degrees Fahrenheit). The new formulation was well-tolerated in animals. The findings were published recently in the scientific journal Vaccine.
Public health officials have been searching for decades for practical methods to deliver vaccines into remote places of the African bush, where there’s no consistent source of electricity, or enough space in refrigerators. Current vaccines, except for the oral polio vaccine, must be shipped and stored in a “cold chain” that preserves them at temperatures between 2 and 8 degrees Celsius (35.6 degrees to 46.4 degrees Fahrenheit), according to the World Health Organization. Any method that allows major vaccines to be stored for a year at room temperatures, instead of in refrigerators, could make it much easier to store vaccines in hot, remote places, where millions of people live around the world.
Along with improved sanitation, mass vaccination is one of the key forces credited with raising life expectancies from about 47 in 1900 to about 77 at the turn of the millennium in wealthy countries. Vaccine technology has been improving in recent years, and raising its profile in the pharmaceutical industry. The market is estimated to grow from an estimated $10 billion in 2007 to some $24 billion globally by 2012, according to a research report from Kalorama Information.
“This could be very far-reaching. We hope this will impact the status quo in the future,” says Dexiang Chen, a senior technical officer for vaccine stabilization at PATH.
How did the researchers do it? After years of testing, the scientists found two
