Acute and latent infection of mice immunised with HSV-1 ISCOM vaccine

The effect of immunisation with an HSV-1 antigen preparation (containing at least 6 viral glycoproteins) on primary infection with HSV and the establishment of latency, was assessed in two mouse models (involving either skin or corneal challenge with virus). The vaccine preparation, given either with Freund's complete adjuvant or aluminium hydroxide gel or in the form of immunostimulating complexes (ISCOMS), induced high ELISA antibody responses (highest with HSV as the ISCOM preparation) and low levels of neutralising antibody. In both models, immunisation with the HSV ISCOM preparation significantly reduced the incidence of zosteriform spread of virus and the severity of disease and, in some cases, the incidence of latent infection in sensory ganglia. In the eye model it was possible to show that immunisation with the HSV ISCOMS restricted the establishment of latency almost entirely to the ophthalmic part of the trigeminal ganglion. Protection from establishment of latency correlated with prechallenge antibody levels.