Measles Resurgence and the Need for Monovalent Vaccine
Lately, a significant increase in the number of measles cases has been recorded in many countries worldwide, including the United States, Canada, Mexico, Romania, as well as additional countries in Africa and Asia. As of May 8, a total of 1,001 measles cases have been confirmed in the U.S. Of these, 30% occurred in children under five years of age, and 96% involved individuals who were either unvaccinated or whose vaccination status was unknown. Thirteen percent of the cases required hospitalization, and three deaths were reported.
The currently recommended measles vaccination schedule for children in the United States includes a first dose administered at 12–15 months of age and a second dose at 4–6 years of age. Infants aged 6 through 11 months who are traveling internationally should receive one dose of MMR vaccine prior to departure. However, this early dose does not count toward the routine two-dose series; these children should still receive the standard doses at 12–15 months and 4–6 years of age. Due to these recent outbreaks, health authorities are taking appropriate measures and implementing adjustments to national childhood immunization policies as needed. Nevertheless, any modification of the vaccination schedule due to the measles outbreak and concerns regarding further spread also affects the immunization policies for mumps and rubella, as the available commercial vaccines are combined formulations. This situation is suboptimal from a professional standpoint and reflects the commercial interests of vaccine manufacturers. A responsible regulatory authority should have required manufacturers, as a condition for approval of the combined vaccine, to also maintain the supply of monovalent vaccines.
