"It's fantastic that more than 76,000 children from one to four years old have received a free ACWY meningococcal vaccine, but we still have 45 percent of children under the age of five who are not vaccinated," he said.
"We are extending the vaccination program to give parents more time to vaccinate their children, but this is not something that should be postponed."
"Meningococcal disease is deadly, and I ask parents to take advantage of this extended program and make sure their children are protected against this disease."
B-chain vaccines are not covered by the program, and parents have to pay around $ 65 to access the vaccine privately.
Babies are vaccinated against the meningococcal C chain as part of their 12-month-old vaccines.
Adolescents receive a free ACWY vaccine at school or university between the ages of 15 and 19.
Children and adults who do not fall into the correct age ranges for a free ACWY vaccine can access the vaccine privately through their GP for around $ 140.
Symptoms of meningococcal disease include high fever, chills, headache, stiff neck, nausea, vomiting, confusion, and joint pain.
Young children may have a fever, appear lethargic, have a pale complexion or with spots or a rash or vomit.