Nonhuman primate models of encephalitic alphavirus infection: historical review and future perspectives

► The disease caused by VEEV, WEEV, and EEEV in macaques resembles the human disease. ► Viral dose required to cause disease in macaques is a concern. ► Studies needed to understand pathophysiological mechanisms determining outcome. ► Marmosets are an intriguing alternative model but more work is needed. ► Vaccine studies suggest neutralizing antibody is a good correlate of protection.