Let Them Wear Silk

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Vaccines are a powerful preventive therapy, yet many would be surprised how unstable they are to even small changes in temperature. Without refrigeration, vaccines can lose their potency and become unusable. Antibiotics also need cooling. While that is not a problem in the U.S., it is in developing countries where a clinic may be a hut.

Refrigeration accounts for eighty percent of a vaccine's cost, yet half of the world's vaccines are still lost yearly from cooling problems. That is why researchers have intensely focused on stabilizing vaccines and other drugs in room temperature or higher. And, they've come up with an unexpected solution: by wrapping them in silk.

That's great! My vaccine will dress better than me! Silk is a protein that in a purified state forms sheets with strands of amino acids that are cross linked to give it strength. Inside these sheets are small pockets that researchers can place vaccines and drugs where they can be protected from extreme changes in temperature and moisture.

For example, the MMR vaccine for mumps, measles and rubella was stable up to six months at body temperature and even at one hundred forty degrees Fahrenheit for an extended period of time. At that same temperature, silk also was able to protect two common antibiotics penicillin and tetracycline.

This technology can drastically lower waste and cost, and make medically vital drugs more available. Future research could identify other protective proteins, but for now, the best vaccines and drugs in the future may be "wearing silk".

More Information

Stabilization of vaccines and antibiotics in silk and eliminating the cold chain
Proc Natl Acad Sci, USA PNAS 2012 vol. 109 (30) 11981-11986.
This is the original research article describing the use of silk proteins to protect vaccines and antibiotics.

New Silk technology Preserves Heat sensitive drugs for Months without Refrigeration
Nice summary of the research from Tufts University posted by Bioscience Technology.

Vaccines.gov
Vaccines.gov is the federal gateway to information on vaccines and immunization for infants, children, teenagers, adults, and seniors. Vaccines.gov provides resources from federal agencies for the general public and their communities about vaccines across the lifespan.

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