50 years ago: how prepared were our minds?

In 1956, when we started our collaboration, both Alick Isaacs and myself had done previous work on interference between inactive and active influenza viruses. We were aware of the state interference research had reached and of the two alternative explanations that had been envisaged.

Women scientists in typhus research during the first half of the twentieth century.

Several women scientists have contributed to typhus research, which carried an exceptionally high risk of laboratory infection. The work of five of them, Ida Bengtson (1881-1952), Muriel Robertson (1883-1973), Hilda Sikora (1889-1974), Hélène Sparrow (1891-1970) and Clara Nigg (1897-1986), is reviewed and the names of several others are mentioned. The lives of these women seem typical of rickettsiologists and reflect the disasters that befell the world during the first half of the twentieth century.

Hermann Mooser, Typhus, Warsaw 1941.

Hermann Mooser (1891-1971), a Swiss rickettsiologist, sent his friend Peyton Rous (1879-1970) of the Rockefeller Institute (New York) a telegram on November 3, 1941, asking for financial help for the manufacture of typhus vaccine in Zurich for the Warsaw Ghetto. His explanatory letter from November 4 reached Rous too late to have any influence on the negative decision (by the Rockefeller Foundation and the American Red Cross) in this matter. Contrary to Weindling's affirmation Mooser was neither in Warsaw in 1941, nor was he a member of the Swiss Sanitary Missions to the eastern front.

Typhus vaccine developments from the First to the Second World War (on Paul Weindling's 'between bacteriology and virology...').

After the louse transmission of epidemic typhus had been established (1909), a small microorganism (thought to belong to a new genus, Rickettsia) was shown in enormous numbers in the guts of lice that had fed on human typhus victims. Attempts at cultivating this organism on inert media failed; transfer from louse to louse without loss of virulence for the vertebrate host was successful. Some scientists were not convinced of the etiologic role of Rickettsiae, because the presence of this microbe in blood and organs of victims or of experimentally infected animals was difficult to demonstrate. This uncertainty was dispelled in 1928, when in guinea pigs infected with material from the closely related disease Tabardillo (murine typhus) abundant Rickettsiae were revealed in the tunica vaginalis. Live vaccines, derived from strains of murine typhus and deployed in French North Africa, were considered by outside observers as unsafe. Killed vaccines were derived from the masses of Rickettsiae present in louse guts, in chick embryo yolk sacs or in vertebrate lungs. These developments were not spurned by any 'upswing of virology' but by the threat of typhus in endemic areas and, after 1938, in a war-torn world. Their basis was firmly anchored in bacteriological thought styles and techniques.