Varicella hospitalizations in Los Angeles during the varicella vaccination era, 2003-2011: are they preventable?

•This manuscript provides data on vaccination status of hospitalized varicella cases, severity of hospitalized varicella cases and reasons for admission that has not been previously described.•Nearly half of hospitalized varicella cases could have been prevented.•Nearly half of the deaths due to varicella could have been prevented.•A small number of vaccinated children were hospitalized for varicella.•Ongoing monitoring will provide a better understanding of breakthrough varicella.