Abstract
Antigenic relationships of simian virus 41 (SV41) to other paramyxoviruses were examined by immunoprecipitation of isotope-labelled SV41-infected cell lysates with specific antisera. SV41 is closely related to the group comprising human parainfluenza virus 2 (HPIV-2), simian virus 5 (SV5), parainfluenza virus 4 and mumps virus. Slight cross-neutralization was detected between SV41, HPIV-2 and SV5. Anti-SV41 activities were detected in 21 of 1116 human serum specimens, indicating that a proportion of the human population is infected with SV41. The haemagglutininneuraminidase of SV41 was preferentially immunoprecipitated by anti-SV41 positive sera.