Wu Q, Wang X, Chen Y, et al. - Using joinpoint regression models, trends in school varicella outbreaks from 2006 to 2017 were evaluated in order to examine varicella outbreak trends among schoolchildren during the voluntary single-dose varicella vaccine (VarV) era in Shanghai, China. A total of 265 varicella outbreaks including 3,263 people were reported in Shanghai from 2006 to 2017. It was noted that to limit school outbreaks, even with high coverage, single-dose VarV is inadequate. However, for varicella outbreak control, the administration of VarV as PEP was an appropriate intervention, former to executing a two-dose VarV schedule.