SEATTLE—The same organization that created the tiny dot that tells health workers around the world if a vaccine is still fresh has come up with another way to keep vaccines safe and useful: an inexpensive additive to prevent medicines from freezing.
“Every country we’ve gone into to look at this says they don’t have a problem with it, and every time we look into it, we find they do,” Debbie Kristensen, an expert on vaccine technologies at Seattle-based PATH, told the Seattle Post-Intelligencer.
Most vaccines must be kept within a fairly precise temperature range to remain effective, and you can’t tell if a vaccine has been overheated or frozen just by looking at it.
The U.S. Centers for Disease Control and Prevention estimates that poor refrigeration wastes hundreds of thousands of doses of vaccine every year.
PATH specializes in devising simple, inexpensive solutions for health problems in the developing world. In the early 1980s, the organization worked with the World Health Organization to develop a heat-sensitive label now used by UNICEF, the World Health Organization and others to flag vaccines exposed to temperatures high enough to kill the vaccine.
Now Kristensen and her colleagues at PATH, along with researchers at the University of Colorado-Denver, have come up with a potential solution for protecting vaccines against freezing.
They report in the current edition of the journal Vaccine on their successful use of common food additives—glycerin, propylene glycol and polyethylene glycol—to protect vaccines from freezing.
“These are widely used in food, soft drinks, shampoos and many other products, including medical products,” said Dexiang Chen, one of the researchers at PATH. And, notes Chen, they’re very inexpensive.
“They cost maybe one penny for 10 doses,” he said.
Though the additives have a well-established history of safe and wide use in food and health products, Kristensen said more research must still be done to determine if using them in vaccines might affect the drugs’ efficiency at protecting against disease.
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Information from: Seattle Post-Intelligencer,
