This special issue of the journal is dedicated to the recent research progress on human herpesviruses (HHVs). Human herpesviruses are distributed worldwide, and more than 90% of adults are infected by one or multiple HHVs. The HHV family contains three sub-families: the alpha sub-family [herpes simplex virus 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV)], beta sub-family [human cytomegalovirus (HCMV), HHV6, and HHV7)], and gamma sub-family [Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV)]. All the viruses typically establish latent infection in host, and undergo lytic reactivation in certain pathophysiological conditions. Figure 1 illustrates a typical herpesvirus virion, which is a spherical particle with 150-200 nm in diameter, containing a T=16 icosahedral capsid and glycoprotein spikes protruding out. In this issue, we collectively present ten articles focusing on the epidemiology, pathogenesis, and interventions of HSV-1, VZV, HCMV, EBV and KSHV respectively, and these high-quality review and research articles are contributed by experts on those specific viruses.The first part deals with the prevalence of Kaposi's sarcoma-associated herpesvirus (KSHV). Firstly discovered in 1994, KSHV is the etiologic agent associated with Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD), all of which arise preferentially in the immunocompromised people. KSHV prevalence varies among geographical regions and populations. Zeng and colleagues report an investigation on the KSHV prevalence in Uygur and Han populations from the Urumqi and Kashgar regions of Xinjiang, China. They find the potential correlation between KSHV prevalence and different ethnicities in endemic areas of Xinjiang, and several environmental factors including population migration may affect KSHV infection rates or KS incidence (Zheng et al., 2017). Meanwhile, Zhang and colleagues report a comprehensive meta-analysis on the epidemiological features of KSHV among intravenous drug users (IDUs) worldwide, and find IDUs are at higher risk of the KSHV infection globally, when compared with the general population, regardless of geographical region or HIV-infection status (Fang et al., 2017).The second part of this issue focuses on the pathogenesis and virus-host interactions during herpesvirus infections, and includes several review and research articles. A review article by Qin and colleges summarizes the latest progresses on the role of lipid biosynthesis and metabolism in the pathogenesis of KSHV (Dai et al., 2017). As growing studies have shown that herpesviruses can hijack extracellular vesicles to ensure their survival and persistence, Lu et al. provide an updated review on the emerging functions and effects of extracellular vesicles that herpesviruses utilize for virus infection-associated intercellular communication and microenvironment alteration, which gives us a better understanding about the pathogenesis of herpesviruses . As