Preventing human disease

A twelve year effort by the World Health Organization resulted in the complete eradication of smallpox from the planet in 1980. The cost of smallpox vaccination, quarantine programmes and treatment totalled more than US$300 million in 1968 alone. The eradication programme, by contrast, cost $300 million over the whole of its twelve year-life and is considered to now save an estimated $1,000 million a year in vaccination and monitoring. Formerly smallpox was a world-wide disease which in 1967, the year when the programme began, killed somewhere between 1.5 and 2 million people; perhaps half a million more were blinded and more than 10 million were seriously and permanently disfigured. In the early 1950s the toll from smallpox had been three or four times greater. Since smallpox has now been eradicated routine vaccination against smallpox is no longer justified. International certificates of vaccination against smallpox are no longer required by any travellers. Stocks of the virus are maintained in 1990 by the USA and the former USSR but may be destroyed by agreement between both countries.

Since the widespread introduction of vaccination against poliomyelitis, around 1957, the incidence of this killing and crippling disease has been eradicated from the western world. However, in large areas of Africa, Asia and Latin America the incidence appears to have been rising disconcertingly during recent years, and large outbreaks are being reported there with increasing frequency. In many tropical countries paralytic poliomyelitis is a far more common disease than had been appreciated. The WHO estimates that 220,000 children are paralysed and 23,000 killed by polio every year in developing countries. The global elimination of polio is technically feasible and is targeted as one of the six vaccine-preventable diseases by the WHO's Expanded Programme on Immunizations.