Three students in the Sanford school district were administered a flu vaccine without the consent of a parent, according to the health care provider that was contracted to give the vaccinations.

Northern Light Home Care and Hospice confirmed that three students received the seasonal vaccine during a recent series of flu shot clinics put on by the school district. Complaints from parents about the unapproved shots was first reported by News Center Maine.

“Yes, three children were vaccinated without fully executed, or completely documented consent,” Northern Light Home Care and Hospice spokeswoman Jacqueline Welsh said in a statement emailed Tuesday night.

She did not respond to questions about how and why the errors occurred and what measures are in place to ensure that it does not happen again.

“Northern Light Home Care & Hospice was contracted by the Sanford school district to provide influenza vaccines to students,” Welsh said. “We have no additional information to share other than to say that we are the largest provider of School Located Vaccine Clinics in Maine. This program is proven to help prevent the spread of influenza from school to home and into the community.”

The ages of the children who received the shots were unknown, but in a report Tuesday by News Center Maine, the parent of a seventh-grader said his daughter was one of the three who received a shot without permission.

George Kimball said he was more than a little upset when he found out.

“She had the paperwork in her hand and she asked me, ‘Did you sign me up for a flu shot?’ and I said no, and she said, ‘Well I got one,” Kimball told the TV station.

Sanford Superintendent Matthew Nelson told the station he is investigating complaints by parents.

“(We) became aware that there might have been an issue with protocols and procedures that were not followed completely,” Nelson said.

Since Oct. 20, Northern Light has held 11 clinics at six of the district’s schools. Sanford has one more vaccination clinic scheduled for Nov. 4 for students learning from home.

Nelson said the permission slip for flu vaccines is included in the packet of forms that parents receive at the beginning of each school year. Information about the consent forms are also shared with the healthcare provider, Nelson said.

Welsh did not respond to questions about how the consent forms are shared with medical providers on the site of each clinic, and what Northern Light does to ensure they are accurate and complete.

Note: This story was updated at noon Wednesday Oct. 28 to correct the full name of Northern Light Home Care and Hospice.