LAT and disease arising from reactivation of latent virus: The observation of mice infected with these two mutants compared to mice infected with the wild-type strain indicated that the mutant RL1-LAT-HSV-2 has an attenuated phenotype with reduced pathogenicity during both acute and latent infections and induces a stronger specific immune response than the wild-type strain, whereas the attenuation effect was not found in mice infected with the LAT-HSV-2 mutant containing the LAT gene deletion.