MANAHAWKIN, N.J. (CBSNewYork) — More than 900 children in Ocean County may not have been vaccinated properly.

As CBS2’s Meg Baker reported, the mother of two happy and healthy looking boys, was extremely concerned about her children’s health after discovering that they may not have been properly vaccinated.

“I don’t feel comfortable with this office anymore,” she said.

The mother came to the Southern Ocean Pediatrics and Family Medicine Office of Dr. Michael Bleiman to get her children’s records after the state filed a complaint alleging gross negligence, professional misconduct, and other violations by ‘Dr. Mike’ as he likes to be called.

“My little ones vaccinations may not be up to date at all because he was born November 2014, so we are going to go to another doctor. See what they can do for us,” she said.

An investigation by the New Jersey Department of Health discovered that vaccines for measles, mumps, rubella, chickenpox, hepatitis A and B, rota virus, DTaP/Tdap, HIB, pneumococcal, polio, meningococcal, and HPV were not properly refrigerated.

This effects families who have medicaid and participated in the Vaccines for Children program, a federally funded, state operated program from November 2014 to July 28, 2016.

Dr. Mike wasn’t available over the phone, and a walk-in by a CBS2 news team did not result in a comment.

The vaccinations are given to children from birth through adolescence and doctors said they may have to be given the shots all over again — no easy task for kids who don’t like needles.

“I’m scared to re-vaccinate, because I don’t want to give too much if it’s already in him,” one mother said.

But there are options.

“We recommend patients have blood work drawn so that we can check something called ‘tightens’ basically that tells me — did your child mount an immune response to the vaccine that I gave?” Dr. Michelle Verdi explained.

Doctors can see if there are antibodies in the blood for those preventable diseases. If so, you would not need to be re-vaccinated.

CBS2 asked the Department of Health how often they perform routine compliance visits, and if they found this out in July, why was there a delay in alerting parents. There has yet to be a response.

The health department is mailing letters to impacted families whose children were vaccinated at Southern Ocean Pediatrics and Family Medicine in Manahawkin.