Parainfluenza 2 Virus: Increase in Hemagglutinin Titer on Treatment With Tween-80 and Ether.

Abstract
Summary Treatment with Tween-80 and ether resulted in a marked increase in hemagglutination (HA) titer of parainfluenza 2 virus, a slight increase for parainfluenza 3 and mumps viruses and no increase for parainfluenza 1. This parainfluenza 2 hemagglutinin had no infectivity, and the HA titer remained unaltered at 4°C for 8 weeks. The hemagglutination inhibiting antibody titers of sera tested with this antigen were slightly higher than the titers obtained with untreated antigen.