India, Jan. 21 -- Vaccines go a long way in managing, controlling, eliminating deadly, sometimes debilitating infectious diseases. Smallpox was the first example of a dreaded disease, with a mortality rate as high as 30 per cent, being eradicated by a vaccine. But it was a long journey from the development of the vaccine to the elimination of the disease. Edward Jenner, an English physician, was the first to demonstrate the effect of a vaccine in 1796.

The World Health Organisation (WHO) initiated a campaign to eradicate smallpox in 1959, but despite their best efforts, smallpox was still widespread in 1966, causing regular outbreaks in multiple countries. Then in 1967 efforts were intensified and scientists came up with a higher quality...