Varicella zoster virus vaccines: an update

Giovanni Gabutti,1 Niccolò Bolognesi,2 Federica Sandri,2 Caterina Florescu,2 Armando Stefanati11Department of Medical Sciences, University of Ferrara, Ferrara, Italy; 2Postgraduate School of Hygiene and Preventive Medicine, University of Ferrara, Ferrara, ItalyAbstract: Varicella zoster virus (VZV) is the etiological agent of varicella, a highly infectious, self-limiting disease with serious complications. The decline in cell-mediated immunity (CMI) that occurs with aging or immunodepression causes a reactivation of the latent VZV as herpes zoster (HZ). Prevention of VZV through varicella vaccination strategies allows to avoid the primary infection in newborns and susceptible subjects. Available monovalent and combined VZV vaccines are effective, safe and generally well tolerated. Universal varicella vaccination has significantly impacted on incidence, complications and deaths related to this disease. Prevention of HZ through vaccination is a priority to avoid the significant burden of its incidence and complications. Currently two HZ vaccines are available. The recombinant zoster vaccine (RZV), approved by the FDA in 2017 and Zoster Vaccine Live (ZVL) licensed in the United States by the FDA in 2006. The advisory committee on immunization practices (ACIP) preferentially recommends RZV. ZVL remains an option for prevention of HZ in immunocompetent adults aged ≥60 years, although the CMI tends to wane a few years after vaccination.Keywords: epidemiology, varicella vaccine, recombinant zoster vaccine, Zoster Vaccine Live, vaccination strategies