US scientists have devised a new way of storing and delivering vulnerable antibiotics and vaccines, with a little help from the silk moth. Infectious diseases kill millions of children every year, and continue to do so in the developing world more than two decades after the World Health Organisation, Unicef and charities such as Rotary International launched a campaign to eliminate polio and immunise every child against the six biggest killers.

Civil war, corruption, ignorance and poverty all created problems, but one of the biggest is simply the fragile nature of vaccines: they tend to deteriorate rapidly unless kept in the refrigerator. This is a problem even for Britain's National Health Service. It is a much bigger problem in hot, humid regions without clinics, electricity or clean water – those regions where children are most at risk from mumps, measles and rubella, from gastric infections and pulmonary diseases, and where the wild polio virus still presents a threat.

Two researchers from Massachusetts report in the Proceedings of the National Academy of Sciences that they took a closer look at the curious properties of the proteins made by the Bombyx mori, which spins a commercially useful little cocoon that must withstand rain and dramatic temperature changes and protect vulnerable organisms. They identified components of the silk that were strong, moisture-resistant, biocompatible and stable at high temperatures, and began experimenting with new ways of conserving MMR vaccines and penicillin in gels, matrices and tiny pockets of silk. The latest news is that, after six months at 37C and even 45C, the experimental silk-wrapped vaccines were still potent. This is a technology still to be tested in the field, but if it works it could replace the costly, cumbersome and precarious "cold chain" of delivery from manufacturer to mobile village clinic.

There are three lessons to be drawn. One is that science can help the poorest: sickness and suffering hamper development as much as corruption, poverty and natural hazard. The second is that the phrase "natural capital" is not just a truism: it is palpably true. People have been exploiting the magic mix of mulberry, moth and silken cocoon for thousands of years, but clearly the silkworm has much more to tell us.

The third is that entomologists had to ask questions about insect life cycles; materials scientists had to explore the polymer chemistry of living tissue; and engineers with a background in biology had to experiment with fabrics fashioned by millions of years of trial-and-error evolution and invent a science called biomimetics. Finally, somebody had to recognise a solution in search of a problem. Pure science pays dividends – unpredictably, but dividends all the same.