Anita C. Ley

Some Characteristics of SSPE Measles Virus

Summary The in vitro comparison of two SSPE measles virus isolates and conventional measles virus demonstrated antigenic identity between these viruses. However, neutralization tests showed an avidity of the SSPE patients neutralizing antibody towards the wild measles virus rather than to the virus isolated from diseased brain. The cytopathology and plaque formation of these measles virus strains revealed greater resemblance between the SSPE measles and the vaccine strain of the virus than between SSPE measles and wild virus. Differences were found in the growth characteristics of the two SSPE virus isolates as measured by tissue culture assays.

EPIDEMIOLOGY OF MONGOLISM IN THE COLLABORATIVE PROJECT

The etiology of mongolism has been of considerable interest to investigators in the Collaborative Project. In a recent publication some of the obstetric and clinical findings which characterized the mothers of 61 mongoloid infants in the Collaborative Project were reviewed and compared to a matched control gr0up.l It was reported that the incidence of mongolism in whites and Negroes was nearly equal. There was no difference in parity, pregnancy-free interval, number of prior abortions or medical history between the study and control groups. Both birth weight and duration of pregnancy were slightly less for the study group than for the controls. The drug and x-ray experiences of the study and control groups were similar. The present report extends the analysis of obstetric factors for the mothers of mongoloid infants and matched controls and includes consideration of the pediatric findings for the children and controls. Because of the serological testing in this investigation, the method of selection of controls was not the same as in the previous study.

Antibody Responses in Acute and Chronic Rubella

Summary Comparative antibody tests for rubella were conducted with the neutralization, indirect fluorescent, and complement fixation methods. All of these techniques demonstrated slightly different patterns of antibody response. Sero-conversion with infection was detected in almost all cases with the 3 methods. Antibodies detectable by fluorescent antibody and complement fixation tests decreased after 15 months following infection. By 10 to 20 years following rubella half of the CF tests were negative. Con-genitally infected children showed a decrease in antibody between the first and fifth month of age which was most marked in the CF test. Their full antibody response in these cases did not occur until after the sixth month.

Antibody Response of Various Strains of Rubella Virus When Inoculated into Rabbits

Summary The inoculation of New Zealand white rabbits with four low passage or wild rubella virus strains and four vaccine strains gave differences in antibody response and virus shedding. These differences can be useful as markers of strain differences and for studies of mechanisms of attenuation. The low passage wild virus strains produced high antibody levels and variable amounts of virus shedding. The vaccine strains resulted in little or no antibody and no virus shedding.