Since the introduction of two polio vaccines 60 years ago, this terrible disease has gone from the death of millions of people (and much more disabling) to virtual elimination. However, the gap between near-extinction and the complete abolition of the virus turns out to be difficult to bridge. As long as small reservoirs of such an infectious disease survive, there is a chance for it to come back.
Barriers to elimination include the Western anti-vaccination movement and Islamic fundamentalists opposed to modern medicine, but there are also technical challenges. Vaccines require refrigeration, something difficult without an electrical network. The invention of a stable vaccine at room temperature could change the deal.
"Stabilization is not witch, so most academics do not pay much attention to this area," said Woo-Jin Shin of the University of Southern California in a statement. "However, as wonderful as drugs or vaccines are, they are not stable enough to be transported, it does not do any good to anyone."
Shin is the first author of the paper in mBio announcing a stable polio vaccine, effective after four weeks of storage at room temperature. There is nothing new in the concept. Freeze-dried measles, typhoid and meningococcal vaccines have been distributed in many isolated areas, helping to reverse the course of these infections.
However, previous attempts at lyophilization and rehydration of polio vaccines have hindered their efficacy and the methods used in other cases have not worked. Shin has found a way around this problem by using laboratory techniques that allow for much faster testing of ingredient combinations.
With only 22 polio cases reported in the world last year – and we hope that existing vaccines and portable solar energy units will complete the work – the widespread application of Shen's work is far away to be guaranteed.
Even if that happens to be the case, however, the techniques used here may be applicable to lyophilization of other vaccines or delicate drugs. The work took place because Professor Jae Jung, Shin's supervisor, met with a friend of his student time, Dr. Byeong S. Chang, who now runs Integrity Bio, a company working on stabilization.
"He and I decided to do it as we get older and we have to contribute directly to people's health and lives," said Jung. "Creative ideas always start with food and drinks."
Shin worked on the inactivated virus, given by injection, and was the original breakthrough against polio. The easier oral vaccine, which uses a weakened form of the virus, has largely replaced it for a while. However, the weakened virus causes paralysis in three cases per million doses, which has led some countries to return to the origin.