A considerable fund of information has been accumulating on the properties of live-virus poliomyelitis vaccines and on the use of these vaccines in human beings. The recent publication of the proceedings of the conference on live poliovirus vaccines, held in Washington, D. C., June 22-26, 1959, under the auspices of the World Health Organization and the Pan American Health Organization, provides a good opportunity to review the current state of knowledge.
The proceedings contain progress reports on field studies of these vaccines now under way in countries in Europe, Asia, and South America. Great numbers of people have been vaccinated in the U. S. S. R. and elsewhere. In general, the reports indicate a good record of safety for the vaccines under trial, although the extent of surveillance and follow-up study is somewhat unclear.
The attenuated live viruses used in these vaccines have lost the power to produce disease through