RESUMO
A comparative study of the antigenic and biological properties of parainfluenza type 2 viruses revealed the existence of two variants among them. The first variant includes strains isolated up to 1965 inclusive, the 2nd those isolated in 1966--1974. The strains of the 2nd variant are characterized by poor interaction with antibody in immune sera to the reference virus which appears to be due to a loss of one of the antigens in them. Besides, they have comparatively low immunogenicity and the hemagglutinating activity and higher sensitivity to inhibitors. The paper emphasized the necessity of using immune sera to strains isolated in recent years, in addition to reference sera, for identification of new isolated of parainfluenza type 2 virus.
Assuntos
Vírus da Parainfluenza 2 Humana , Variação GenéticaRESUMO
A comparative study of the antigenic properties of parainfluenza type 1 viruses revealed the existence of 2 serological variants among them. The expedience of using the reference and recent years of isolates of parainfluenza type 1 viruses for serodiagnosis was demonstrated. Highly immunogenic strains isolated in 1971 were selected for properation of hyperimmune sera. It is necessary for identification of new isolates of parainfluenza type 1 viruses to use antisera for strains isolated in recent years alongside with reference immune sera.
