Amid a growing measles outbreak, more parents are choosing to alter the recommended vaccine schedule for their children in hopes of not overwhelming their immune systems, a practice doctors say could be just as risky as not vaccinating at all.

Dr. Paul Offit, a physician in the Division of Infectious Diseases and Director of the Vaccine Education Center at Children’s Hospital of Philadelphia, told the Washington Examiner he has seen an uptick in parents asking whether they should alter the vaccine schedule recommended by the Centers for Disease Control and Prevention.