More than 80% of measles cases reported in the United States in 2015 were in people who were either unvaccinated or had unknown vaccination status, according to a report from the Centers for Disease Control and Prevention.
A total of 159 measles cases have been reported in the first 3 months of 2015, 153 (96%) of which were import related, with 111 (70%) cases associated with one breakout in Orange County, California. Of those who contracted measles, 68 (43%) were unvaccinated, 60 (38%) had unknown vaccination status, and 28 (18%) had received the vaccine. Among unvaccinated patients, 29 cited religious and philosophical objections to vaccination, 26 were too young, 1 had other contraindications, 3 had missed vaccination opportunities, and 9 cited other reasons. Patients ranged in age from 6 weeks to 70 years.
“Maintenance of high two-dose MMR vaccine coverage has been crucial in limiting measles spread from importations in the United States. Most measles importations occur when U.S. citizens travel abroad and have not been appropriately vaccinated. Therefore, it is important to encourage timely delivery of measles vaccination for U.S. residents before overseas travel,” the CDC investigators recommended.
Find the full report in the MMWR 2015, April 17;64:373-6).