A new polio vaccine may mean the disease will be eliminated in as little as three years.
Most of the people in the world grew up thinking of polio as one thing, and as a thing of the past. Sadly, polio is still a problem, especially in India and Nigeria. One of the reasons for its continued existence is that it is not a monolithic disease but three different strains. Strain 2 was mostly eliminated by the first round of vaccinations.
Strains 1 and 3 still plague people to this day. Although vaccinations against the disease were on the market, they were unable to stop the spread. Recently, a new vaccine is being tested and getting good results. Past vaccines were either monovalent - taking care of one of the strains - or trivalent - targeting all three.
The newest vaccine is bivalent, targeting strains 1 and 3. Subjects show a much greater immune response than they did to previous vaccines. More tellingly, polio cases in both Nigeria and India have dropped fast. Nigeria in particular is seeing a 98% drop in cases since last year. With any luck, polio will be completely eradicated before 2014.