Scientists may have finally found a way to deal with one of developing world's worst problems in healthcare — faulty and inadequate cold chain for vaccine storage. British scientists from Oxford University have found a way to keep vaccines stable even in room temperature.
This could come as a boon for India where reports of vaccines going spoilt due to bad cold storage facilities are common. The new technology could mean no fridges, freezers and associated health infrastructure for vaccines — significantly bringing down costs of vaccination.
Oxford University carried out the proof-of-concept study, showing that the vaccines they were developing could be stabilized for months using Nova Bio-Pharma Technologies' patented technology called the hypodermic rehydration injection system (HydRIS).
The team demonstrated it was possible to store two different virus-based vaccines on sugar-stabilized membranes for 46 months at 45 degrees Celsius without any degradation.
The vaccines could be kept for a year and more at 37 degree C with only tiny losses in the amount of viral vaccine re-obtained from the membrane.
“Currently, vaccines need to be stored in a fridge or freezer. That means you need a clinic with a nurse, a fridge and electricity supply, and refrigerated lorries for distribution. If you could ship vaccines at normal temperatures, you would greatly reduce cost and hugely improve access to vaccines. You could even picture someone with a backpack taking vaccine doses on a bike into remote villages,'' said lead author Dr Matt Cottingham of the Jenner Institute at the University of Oxford.
The method involves mixing the vaccine with the sugars trehalose and sucrose. The mixture is then left to slowly dry out on a simple filter or membrane. As it dries and the water evaporates, the vaccine mixture turns into a syrup and then fully solidifies on the membrane.
The thin sugary film that forms on the membrane preserves the active part of the vaccine in a kind of suspended animation, protected from degradation even at high temperature. Flushing the membrane with water rehydrates the vaccine from the membrane in an instant.
“The beauty of this approach is that a simple plastic cartridge, containing the membrane with vaccine dried on, can be placed on the end of a syringe,'' Dr Cottingham said.
Pushing a liquid solution from the syringe over the membrane would then release the vaccine, which can then be injected into the patient, Dr Cottingham added.
Preparing vaccines that do not need refrigeration has been identified as one of the major unsolved problems in global health.
WHO's immunization programme vaccinates nearly 80% of the children born today against six killer diseases polio, diphtheria, tuberculosis, whooping cough, measles and tetanus.
One of the biggest costs is maintaining what's called the cold chain — making sure vaccines are refrigerated all the way from the manufacturer to the child, even if they live in the remotest village. If most or all of the vaccines could be stabilized at high temperatures, it would not only remove cost but also enable more children to be vaccinated.