Abstract
Following the discovery that the virus of mumps can be propagated in the developing hen's egg (1, 2), studies have been carried out at the Harvard Medical School on various properties of the egg-virus. Most of the results will be described subsequently in detail. But in this communication, because of their potential application to the problem of vaccination against mumps, certain experiments will be separately outlined which indicate that the pathogenicity of the virus for the monkey, and possibly for man, decreases on continued passage in the egg. Its antigenicity, however, under such conditions appears to be maintained.
Experiments in Monkeys. In two experiments carried out at different times, preparations of infected amniotic membranes of the 15th and 25th egg passages respectively were inoculated via Stensen's duct into rhesus monkeys (3). Four per cent suspensions in physiologic salt solution were prepared by grinding with powdered alundum in a mortar the amnitoic membranes removed from infected embryos after 5 to 6 days' incubation at 35 C.
Footnotes
These investigations have been carried out as a project of the Commission on Measles and Mumps, Board for the Investigation and Control of Influenza and other Epidemic Diseases in the Army, Preventive Medicine Service, Office of the Surgeon General, United States Army.
