[Vaccines against varicella-zoster virus (VZV)]

In Western countries, two attenuated varicella vaccines derived from the OKA strain are licensed: Varilrix® GlaxoSmithKline (OKA/RIT strain) and Varivax® Merck Sharp and Dohme (OKA/Merck strain). Currently, in Spain, varicella vaccination is only included in the Ministry of Health, Social Services and Equality official vaccination calendar for administration in adolescents who have not had the disease. Given the good results obtained in Navarra and Madrid with universal administration of the vaccine in children, it would be desirable to include the vaccine in the routine immunization schedule, with the administration of two doses at 15-18 months of age in the future. The protective efficacy of the attenuated herpes zoster vaccine was evaluated in the Shingles Prevention Study, which showed that in the short term (0-4 years) the vaccine reduced the incidence of herpes zoster by 53%, post-herpetic neuralgia by 66%, and the disease burden in immunocompetent persons aged ≥60 years by 61%. Another study demonstrated protective efficacy in persons aged 50-59 years. Over time, the protective efficacy decreases, but remains at acceptable levels, especially for post-herpetic neuralgia and the disease burden. Recently, the results of a controlled clinical trial (phase III) conducted in 18 countries to assess the protective efficacy of the inactivated subunit vaccine (glycoprotein E) adjuvanted with the adjuvant AS01B were published. The study inferred that the vaccine significantly reduced the incidence of herpes zoster in the short term (3.2 years) in people aged ≥50 years. Vaccine protection did not decrease with age at vaccination, ranging between 96.8% and 97.9% in all age groups.