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Vaccines in sugar film could save millions
Scientists at Oxford University in the United Kingdom and Nova Bio-Pharma Technologies have developed a method of preserving vaccines very similar to the process used to make candied fruit peel. The sugared vaccines are stable for months at a time even at tropical temperatures, which could be crucial breakthrough for vaccination efforts long hampered by the need for refrigeration.
The vaccines are first mixed with two sugars, trehalose and sucrose. Then the mixture is allowed to slowly dry on a filter. It first turns to a syrup and then a thin, sugary film.
Once in the sugary film, the vaccine is protected from heat in a kind of suspended animation. All it takes to reactivate it is water. The researchers created a simple plastic capsule to hold the paper-like film. It can then be attached to a syringe filled with clean water. The water would wash over the film, dissolve the vaccine and inject it into the patient all in one operation.
The paper describing their work is in the Feb. 17 edition of the journal Science Translational Medicine.
The researchers stored two different virus-based vaccines in sugar film for four months at 113 degrees and they did not degrade.
A huge problem with vaccination efforts has been the need for a continuous cold-chain from the manufacturing site to the person getting vaccinated.
“Currently vaccines need to be stored in a fridge or freezer,” says lead author Matt Cottingham, of the Jenner Institute at the University of Oxford. “That means you need a clinic with a nurse, a fridge and an electricity supply, and refrigeration lorries for distribution.”
The membrane could even be loaded into a simple plastic cartridge that fit on the end of a syringe. Simply pushing water through the cartridge and into a syringe would reactivate it even as it was injected into the patient, says Cottingham.
The process could be used for many vaccine types, the researchers say. Today vaccines for all the major childhood killers - flu, diphtheria, tetanus, whooping cough, polio, mumps, measles and chicken pox –require refrigeration. This new vaccine storage creates enormous possibilities for getting vaccines to people who need them who may be a long way from a refrigerator.
By Elizabeth Weise
