Medical authorities have been quick to point to the anti-vaccine movement as the cause for the measles outbreak in California, but an analysis of the data suggests there may be other contributing factors, from public health measures that targeted only children to lack of access to medical care.
"One [reason] is active opposition, the other is an access problem," says Dr. Walter Orenstein, professor and associate director at the Emory Vaccine Center.
Though the anti-vaccine movement likely is one of the reasons for the outbreak in California, which so far has spread to 73 residents, a U.S. News analysis of data from the California Department of Public Health show that most of those who currently have the virus are aged 20 or older, meaning some were born not only before the anti-vaccine movement swelled, but also before the U.S. implemented aggressive immunization measures.
The majority of the unvaccinated for whom the state public health agency had detailed information were not vaccinated primarily to “personal beliefs," Dr. Gil Chavez, state epidemiologist and deputy director at the Center for Infectious Diseases for the California Department of Public Health, said in an email. She also noted that some were infants younger than 12 months of age who were too young to be vaccinated.
This outbreak follows an already brutal year for the virus, which in 2014 showed a record number of cases since 2000. According to the CDC, 27 states reported 644 cases in 2014, the majority of which were among people who were not vaccinated. Public health agents attributed the spread to travels to the Philippines, which experienced a measles epidemic.
What's Really Behind the Measles Outbreak - US News