Burke RM, Groom HC, Naleway AL, et al. - In the United States, two rotavirus vaccines are licensed and have exhibited high effectiveness against moderate to severe disease. Researchers here investigated rotavirus vaccine effectiveness (VE) against milder disease. From Kaiser Permanente Northwest (KPNW), they extracted active surveillance data to determine rotavirus VE against medically attended rotavirus illness among age-eligible children. Population assessed in the VE analysis included 842 children; of these, 799 (95%) had mild disease requiring at most a clinic visit, and of whom, 698 (83%) were fully vaccinated against rotavirus. Outcomes suggest that rotavirus vaccination effectively protects US children from mild to moderate as well as severe disease. Additionally, this work indicated the effectiveness of rotavirus vaccination against qRT-PCR-defined illness.