The findings could apply to a much wider lot of vaccines since many of the same clinics that provide free immunizations for low-income children also give shots to insured children.
The Centers for Disease Control and Prevention (CDC) turned the microscope on itself and was shocked when the Health and Human Services inspector general found severe storage violations in the federal vaccine program. Ice was found on flu shots, which shouldn't be frozen. Expired doses were also found.
"We found three of four providers were storing the vaccines in temperatures that were either too hot or too cold," said HHS Regional Inspector General Dwayne Grant.
Seventy-five percent of 45 doctors' offices and clinics inspected were storing vaccines improperly.
Experts say that poorly stored vaccines are not deadly or harmful, but they can be ineffective, and that can leave children exposed to the diseases these drugs are designed to protect them against.
"I think doctors need to be taken out to the woodshed on this," said Dr. Richard Besser, ABC News senior health editor. "Doctors need to look in their offices and say, 'OK, how are my nurses doing this? Are our vaccines safe?'"
The CDC is vowing to improve the system with more oversight.
"There have been changes in the equipment, the refrigerators, new cycling refrigerators. There are many vaccines recommended now and it may be that there are more doses being stored in the average office than there used to be," said Dr. Anne Schuchat, director of the CDC National Center for Immunization and Respiratory Diseases.
Besser says it's crucial for children to get their shots so he recommends asking your pediatrician direct questions about how they store their vaccines.