High number of U.S. children remain unvaccinated against measles
Roughly 9 million children under the age of 17 lack immunity to the measles.
HealthDay News — Researchers estimate that one in eight American children are vulnerable to measles, and almost a quarter of those under the age of 3 are susceptible to contracting the disease. These findings were scheduled to be presented at the annual meeting of the Infectious Diseases Society of America (IDWeek), held from Oct. 7 to 11 in San Diego.
Lead author Robert Bednarczyk, PhD, is an assistant professor of global health and epidemiology for the Rollins School of Public Health at Emory University in Atlanta. He and his colleagues analyzed the results of a national survey of immunizations among U.S. adolescents, covering the years 2008 to 2013. Based on their analyses, the authors estimated that of the roughly 70 million children under the age of 17, almost nine million lack immunity to measles. Some children cannot be vaccinated, whereas others are unvaccinated or under-vaccinated.
According to Bednarczyk's team, for measles, at least 92% of the "herd" needs to be immune to protect those who can't be vaccinated, a group that includes infants. The first of the two-shot series of the measles-mumps-rubella vaccine is given when children are 1 year old.
"Right now, in the older ages, we see immunity levels greater than 92%, which should be adequate to prevent sustained measles transmission," Bednarczyk told HealthDay. "But we do not have a very wide buffer." The researchers estimated that elementary school students hover near the 92% mark, but they report that preschool children have the lowest levels of immunity.
- Bednarczyk R, Orenstien WA, Omer S. Estimating the Number of Measles-susceptible Children in the United States Using the NIS-Teen. Presented at: ID Week 2015; October 7-11, 2015; San Diego, CA. https://idsa.confex.com/idsa/2015/webprogram/Paper52216.html