Even when the right drugs are available, they can't always get to the people who need them the most - but this new portable vaccine kit could help.
The pack works by holding freeze-dried pellets that form the basis of several vital medicines, but the real advantage is that no power or refrigeration is required. You just need to add water, and the drugs and vaccines are ready to be administered.
A team from the Wyss Institute at Harvard University has published a paper on their newly developed method, which they've called 'portable biomolecular manufacturing'. The trick is not storing the drugs themselves, but storing their raw ingredients.
"The ability to synthesise and administer biomolecular compounds, anywhere, could undoubtedly shift the reach of medicine and science across the world," said the study's senior author, James Collins.
There are two parts to the kit: one holds pellets containing the chemical machinery that synthesises the end product, and the other holds pellets containing DNA instructions that tell the drug which compound to create.
Mix two parts together in a chosen combination, add water, and the treatment is ready.
All kinds of drugs could be created, said the team: tetanus and flu shots, vaccines against emerging outbreaks of disease, antimicrobial peptides to treat flesh wounds, and more.
In the study itself, the researchers were able to synthesise a vaccine against diphtheria.
When you think about how hard it is to not only get access to, but keep fresh, these treatments far away from hospitals or even power sources (perhaps in the wake of a natural disaster), you can see how vital such a kit might be.
Medicines like this typically need an uninterrupted chain of cold refrigeration at every stage of the transport and storage process.
"This approach could - with very little training - put therapeutics and diagnostic tools in the hands of clinicians working in remote areas without power," added one of the researchers, Keith Pardee, now at the University of Toronto.
The work builds on previous research by the same team that showed how this type of portable cell synthesising could happen outside of a living organism.
Not only are the pellets extremely stable and able to survive for at least a year at room temperature, they're also very cheap to produce. A kit like the mock-up one produced by the Wyss Institute team could be distributed well in advance of any outbreak.
According to the World Health Organisation, more than half of the people sharing our planet live in rural areas. UNICEF statistics show that over 20 million infants didn't get basic vaccination treatments for measles last year.
And it's not just Earth where a kit like this could be useful - one day, it might even be used in space, say the researchers. If you ever get the chance to travel to Mars, look out for one in your astronaut pack.
The study has been published in Cell.