CHICAGO (AP) — A doctors’ survey says parents have increasingly sought to delay vaccines for young children. Physicians worry that makes under-vaccinated kids and others vulnerable to preventable diseases.

The findings are in a national survey of more than 500 pediatricians and family doctors released Monday in Pediatrics. Nearly all said that at least some parents of kids younger than 2 had requested vaccine delays in a typical month. One in 4 said those numbers had increased.

Most doctors said they at least sometimes agreed to the delays. Only 3 percent said they often or always tell parents who insist on vaccine delays to seek care elsewhere.

Vaccinations against 14 diseases are recommended for children under 2. Some shots combine vaccines but children may get five shots at once under the recommended schedule.