This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

Some parents worry that too many vaccinations too close together can affect their child’s health, but a new study finds no link between vaccine schedules and seizures.

The study by Kaiser Permanente’s Institute for Health Research Colorado examines the timing of vaccines and seizures. Dr. Simon Hambidge, lead author of the study, said some parents think a child’s immune system isn’t strong enough for multiple vaccines.

“There is no scientific evidence for this, and there is evidence that it is safe and effective to follow the current recommended schedule,” Hambidge said.

In fact, Hambidge’s team found that delaying vaccines increased the likelihood of seizures, instead of decreasing it. A measles vaccine after 15 months old could raise a child’s seizure risk.

The risk of seizure for children who are vaccinated between 16 and 23 months of age is about 2 in every 4,000 doses. For children vaccinated earlier, that risk is 1 in every 4,000 doses.

According to a study done in 2009 by the National Immunization Survey, more than a quarter of parents delay vaccines, while almost 9% refuse to vaccinate their children.

Vaccinations for measles are especially important right now because of an increase in measles abroad, Hambidge said.

“The risk of not vaccinating a child for measles or for delaying vaccination is that the child is left vulnerable to catching measles, which is a very serious disease,” Hambidge said.