U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Chickenpox (varicella): varicella reporting and surveillance. [Last reviewed: Dec 2018; Accessed: Jan 2021]
Online
U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Chickenpox (varicella): varicella reporting and surveillance. [Last reviewed: Dec 2018; Accessed: Jan 2021]