The family’s 7-year-old boy, who was intentionally unvaccinated against measles, was exposed to the virus while traveling in Europe. When he returned home to San Diego, he unknowingly exposed a total of 839 people, and an additional 11 unvaccinated children contracted the disease. Three of those infected were babies, too young to have yet received the measles vaccines, and one of the babies was hospitalized for three days with a 106-degree fever, according to a report to be published in the April issue of Pediatrics.