Herta Wulff

Respiratory Syncytial Virus Observations on Antigenic Heterogeneity.

Summary Evidence is presented of antigenic heterogeneity between prototype “Long” and “87”strains of RS virus. In cross neutralization tests with animal antisera only the homologous virus strain was inhibited to high titer, while the SDE for the heterologous remained very low, even after 3 or 4 immunization cycles. Human sera failed to reveal disparity. Both strains shared a common CF antigen.

Respiratory Syncytial Virus Properties of Strains Propagated in Monkey Kidney Cell Cultures.

Summary RS viruses recovered in 1962 were cytopathic on MKTCs. MKTCs were much more sensitive (80%) than HEp-2 cells. Seventeen of 24 isolates were revealed between the 3rd and 6th days post-inoculation. Growth curves in MKTCs revealed virus by the 7 th hour, with peak titers at 78 to 96 hours. Rotation yielded a 90% net increase of virus over those obtained in stationary cultures. RS virus is not stabilized by 1 m MgCl2. The virus can be maintained in 50% glycerin for at least 9 months of storage at ≥—20°C. Even at 44dGC the decay rate in glycerin is markedly delayed. Preservation in glycerin is superior to 0.5% gelatin or 20% chicken serum. Preservation was not enhanced by lyophilization.

A new micro-neutralization test for antibody determination and typing of parainfluenza and influenza viruses.

Summary A new microtiter method has been developed for determination of neutralizing antibody titers for parainfluenza viruses and for typing hemadsorbing viruses. The microtiter plates are read macroscopically by hemagglutination pattern. The new method has advantages over both the conventional tube technique and a previously described micro-neutralization test. The results obtained with the new method are comparable with those of the previously described methods.

A microneutralization test for determination of antibodies to rubeola virus.

Summary A new microtiter method for determining serum neutralizing antibodies for measles is described. The test can be read macroscopically by the pattern of hemagglutination. The results obtained by the microtest compare well with those obtained in tube neutralization tests. Philadelphia strain 26 was technically the most satisfactory of the three measles strains evaluated for use in microneutralization tests.