Adding varicella to the measles, mumps, and rubella vaccine in Brazil significantly cut hospital admissions because of varicella-zoster virus (VZV) in children aged 1-4 years, said Marcelo Comerlato Scotta and associates at Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.

A tetraviral combined live and attenuated vaccine including measles, mumps, rubella, and varicella (MMRV) given at 15 months of age was introduced in the Brazilian National Immunization Program in 2013. This study compared the incidence of varicella and herpes zoster admissions in children before (2003-2013) and after (2014-2016) MMRV introduction.

Of the 69,791 admissions caused by VZV in Brazilian patients younger than 20 years, the rate of such hospitalizations for children aged 1-4 years significantly decreased from 27 cases per 100,000 children per year to 14 cases per 100,000 children per year after the vaccine was introduced, a reduction of 48% (P < .001). Changes in other age groups were not significant. That decrease in the rate of VZV admissions remained statistically significant in the vaccinated group after adjusting for seasonality (P < .001).

Direct costs of VZV-related admissions dropped 38% after introducing the MMRV vaccine, the researchers said. “Further studies are needed to evaluate long-term direct and indirect impact on the epidemiology of VZV infections.”

Read more in Vaccine (2017 Dec 1. doi: 10.1016/j.vaccine.2017.11.057.)