In response to reported cases of vaccine-acquired rotavirus infection in infants with severe combined immunodeficiency (SCID) following rotavirus vaccine administration, both Merck & Co. and GlaxoSmithKline Biologicals have revised the prescribing information and patient labeling for their respective rotavirus vaccine products, pentavalent rotavirus vaccine (RV5) and monovalent rotavirus vaccine (RV1), with approval from the Food and Drug Administration (1,2). Merck revised the prescribing information and patient labeling for RV5 in December 2009, and GlaxoSmithKline Biologicals did so for RV1 in February 2010. After the revision to the RV5 prescribing information, CDC sought consultation from members of the former Rotavirus Vaccine Work Group of the Advisory Committee on Immunization Practices (ACIP). On the basis of that consultation and available data, CDC is updating the list of contraindications for rotavirus vaccine. Rotavirus vaccine (both RV5 and RV1) is contraindicated in infants diagnosed with SCID.