A Brief History of Vaccines Against Polio

Poliomyelitis, a dreaded disease of the last century that had already crippled millions of people across the globe, is now on the verge of eradication thanks mainly to two polio vaccines, inactivated polio vaccine (IPV) and oral polio vaccine (OPV). Ever since their development in late 1950s and early 1960s, the journey of their early development process, clinical trials, licensure and ultimately widespread clinical use in different countries provide a fascinating tale of events. Oral polio vaccine has been the mainstay of global polio eradication initiative (GPEI) in most of the countries. With the advent of 'polio endgame', the focus has now shifted back to IPV. However, there are certain issues associated with global cessation of OPV use and universal implementation of IPV in routine immunization schedules across the globe that need to be dealt with some urgency, before proclaiming the global victory over polio.