Poliomyelitis

This chapter addresses how polio was first discovered and then controlled, the problems with its elimination, and the argument for continued vaccination to ensure control. Polio was not defined as a specific disease entity until the late seventeenth century. Meanwhile, paralytic poliomyelitis epidemics first became known in the nineteenth century. Whether or not sporadic outbreaks of paralytic poliomyelitis occurred earlier is less certain and a matter of disagreement. The chapter then looks at the three main personalities who were fundamental in developing the vaccine for poliomyelitis: Jonas Salk, Albert Sabin, and Hilary Koprowski. Jonas Salk and his colleagues chemically inactivated the poliomyelitis virus with formaldehyde and provided a vaccine that produced immunity and dramatically lowered the incidence of poliomyelitis. However, this immunity waned over time. Additionally, administration by needle made vaccinations of large populations difficult. For these and other reasons, Koprowski, Sabin, and others independently worked on the development of a vaccine with live attenuated viruses. Without such combined efforts, the vaccine would never have materialized.

Medical breakthroughs: chance and opportunity

Medical advances of great importance in improving diagnosis, treatment or prevention of disease are often called ‘breakthroughs’. The processes by which breakthroughs are achieved are multiple, but may include necessity (a problem which must be solved), opportunity (the time must be right), chance (the unexpected), curiosity (a desire to understand mechanisms) and ingenuity (ability to find a solution). Discovery can be the start of a chain reaction, so that the breakthrough at the end of the chain becomes “inevitable”. Two examples are given in which these attributes played a part (i) the development of a vaccine against the poliomyelitis virus and (ii) the harnessing of penicillin as a therapeutic agent to treat serious bacterial infections.