(formerly IRIN News) Journalism from the heart of crises

Vaccines that can take the heat

A health department officer prepares a syringe during UNICEF tetanus vaccine campaign to the students of Senior High School SMAN 1 Kepahiang, Kepahiang district, Bengkulu province, Indonesia on November 21, 2008

Researchers in the UK have unveiled a new system of storing vaccines without refrigeration that could cut vaccination costs in poor tropical countries, according to Oxford University.

"You could even picture someone with a backpack taking vaccine doses on a bike to remote villages," said Matt Cottingham, lead author of the study.

The World Health Organization (WHO) estimates that maintaining the equipment needed to refrigerate drugs during delivery and storage - the "cold chain" - costs countries up to US$200 million a year and pushes up the cost of vaccination by 14 percent.

Some vaccines include live viruses that can stimulate the body's immune response without causing infection. Researchers at Oxford and the UK-based Nova Laboratories used sugars to keep viruses in vaccines alive at high temperatures - also known as sugar glassification - for up to one year. The method has been tested over the past decade.

No thanks

Drug manufacturers have been slow to adopt existing technologies that could cut delivery costs. "The [drug] industry is actually reluctant to explore these [technologies] for their existing already licensed vaccines," said Michel Zaffran, director of Project Optimize, a WHO partnership with the US-based Program for Appropriate Technology in Health (PATH).


PATH has been looking at ways to improve vaccine delivery. "The costs involved in re-licensing an existing vaccine can ramp up rapidly because of the time and efforts required to ... demonstrate and confirm safety of the new product," Zaffran told IRIN.

Pharmaceutical companies want to get new vaccines out as quickly as possible, and delays cost time and money.

Pfizer Inc, an international drug company, said it was hard to say how long such a process would take or how costly it would be. "The extent of studies needed to support re-licensing would depend on the extent of reformulation," Pfizer's executive vice president of vaccine research, Emilio Emini, told IRIN. 

Cold chain dogma

Zaffran said over the past 30 years countries had developed a "cold-chain dogma" because most vaccines had required refrigeration. Even though newer vaccines could withstand more heat, delivery systems had changed little. "It is extremely difficult to convince people that some vaccines can be exposed to heat without any danger," he commented.

According to WHO, at least 15 vaccines that are transported and stored at temperatures of two to eight degrees Celsius could withstand heat of up to 40 degrees Celsius - including those to prevent rotavirus, tuberculosis, cholera, and typhoid infections - but Zaffran acknowledged that delivering vaccines at unconventional temperatures could be "perceived as being complicated to manage".

The UK vaccine storage research could "trigger some changes and possibly contribute to bringing about [a] new immunization paradigm", Zaffran told IRIN, but there would also have to be greater demand for such vaccines from hot-weather countries to give drug manufacturers an incentive to adopt the technology.


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