Abstract
The serological relationship between a New Zealand strain of equine herpesvirus type 1 (EHV 1) isolated from the respiratory form of the disease, and one isolated from an aborted foetus was investigated. Cross neutralization tests were carried out using a plaque reduction test.
A marked antigenic difference was obtained when the cross-neutralization product was calculated. This difference suggests that currently available EHV 1 vaccines, which contain only abortion or reference strains of virus, may well be ineffective in preventing disease caused by respiratory strains of virus.