Disease Prevention Vaccines-
Prevention of diseases is the most desirable, most convenient and highly effective approach to health; this is achieved by vaccination or immunization using biological preparations called vaccines.

Vaccines represent an invaluable contribution of biotechnology as they provide protection against even such diseases for which effective cures are not yet available.

The effectiveness of vaccines may be appreciated from the fact that small pox, once a dreaded disease the world over, has been completely eradicated from the world; the last case of small pox was reported in 1977.