Antibody to Rhinovirus in Human Sera. I. Standardization of a Neutralization Test

SummaryThe reproducibility of rhinovirus neutralization tests employing small doses of virus was tested by performing, in blind fashion, neutralization tests on duplicate serum samples from 10 individuals against 5 rhinovirus serotypes and from another 10 individuals against 3 different rhinovirus serotypes. The most reproducible results were obtained on the second day in which 3.2 TCID50 or more were present in the simultaneous virus titration, and the test was made technically easier by classifying as positive only those cultures with diffuse involvement of the cell sheet with CPE. The neutralizing antibody differences between duplicate serum samples appeared to follow a normal distribution. The frequency of 4-fold or greater differences between duplicate samples was 15.6%; 8-fold or greater differences, 5.2%; and 6-fold differences, 2.6%. Variability between duplicate serum samples was found to be related to the level of antibody present.