Polio eradication and ethical issues.

In 1978 the Government of India decided to use oral polio vaccine (OPV) to control polio, occurring then at the average rate of 500 cases per day (2). The primary vaccination schedule was three doses in infancy. The prevailing popular belief (based on theory, not evidence) was that vaccine viruses would spread in the community, immunise unvaccinated children, induce high herd effect, and control polio rapidly. The alternate choice, the injectable polio vaccine (IPV), marginally more expensive, was believed to protect only the vaccinated. Thus, OPV was (erroneously) considered the better ‘public health’ vaccine.