Doctors recommend that children receive their first measles vaccine at the age of 1 year, followed by a second between 4 and 6 years of age.(Photo: Photo: Joe Raedle, Getty Images)

The percentage of unvaccinated children has increased in recent years, according to two reports from the Centers for Disease Control and Prevention.

A According to the report, the percentage of children who received no vaccine before the age of two years has progressively increased from 0.9% for those born in 2011 to 1.3% for those born in 2015. This increase translates into 18,400 more children, the report said.

In 2001, only 0.3% of all children aged 19 to 35 months had received no vaccine.

Although the report suggests that many factors, including access to vaccines and insurance, are at the root of this decline, another report suggests that parental preference may also contribute to this decline.

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This study revealed that last year was the third consecutive school year in which the number of parents requesting an exemption for their school-age children had increased slightly. Overall, however, this second study found that the percentage of children with a waiver allowing them to attend an unvaccinated school was low.

The study found that during the 2017-2018 school year, vaccines against measles, mumps, rubella, diphtheria, whooping cough and chickenpox were nearly 95%.

Dr. Thomas Slama, former president of the American Society of Infectious Disease Control, said that the number of unvaccinated children did not surprise him.

"An increase of 0.9 to 1.3% in children under-vaccinated before the age of 2 is not really striking," said Slama, an infectious disease physician at the Faculty of Medicine's University of Indiana. "If 98.7% of the country were doing well and correctly, I would say it was pretty good."

However, he added, if the numbers continue to increase, this could be worrying.

Health officials fear the return of a number of infectious diseases that vaccines could prevent from pertussis or whooping cough to measles. Recently, an unvaccinated child died of flu in Florida, but the flu shot is not usually required to go to school or daycare.

The report on younger children found that access rather than philosophy often explained why a child had not been vaccinated.

Uninsured and Medicaid children had lower coverage rates than those with private health insurance. Children living in more urban areas had higher vaccination rates than those living in more rural areas.

Call Shari Rudavsky, IndyStar staff reporter, at 317 444-6354. Follow her on Facebook and Twitter: @sudavsky.

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