The Health Service Executive is encouraging parents of those aged between two to 17 to get the free nasal spray flu vaccine.
In a statement, the HSE said the nasal spray gives children the best protection from flu, while also helping to protect others, especially those who are vulnerable.
The vaccine, which is available for free from participating GPs and pharmacies, is sprayed into each of the child's nostrils.
Dr Aparna Keegan, Specialist in Public Health Medicine and Flu Lead at the HSE National Immunisation Office, said that the flu is a "serious illness that can be dangerous in children too".
"The nasal spray flu vaccine is a very safe and effective vaccine and helps your child’s immune system produce antibodies that fight infection," Dr Keegan said.
"It cannot give your child the flu. If your child has had the flu vaccine and they come into contact with flu virus, these antibodies will help them fight the flu and reduce the risk of getting sick or needing to go to hospital."
Speaking on RTÉ's Today with Claire Byrne, Dr Keegan said that children can transmit flu for longer than adults and are more likely to spread the disease.
She said the vaccine, which covers a person from October to April, has been given to millions of people and children worldwide.
Dr Keegan said Australia has had quite a severe flu season with a lot of children infected and it is important that lessons are learned from other countries.
She also said that the National Immunisation Advisory Committee has not made any recommendation yet on offering a Covid-19 booster vaccine to children aged between five and 11.
Minister for Health Stephen Donnelly said the flu vaccine is a "key measure in protecting the community and our health services over the winter months".
"I would like to encourage all those who are eligible to get the flu vaccine to do so as soon as possible; and I would like to take this opportunity to encourage parents with children within this age range to get their children vaccinated against the flu this year."
While most children who catch flu have mild symptoms, flu can sometimes lead to serious complications such as pneumonia or bronchitis in some children.
According to the HSE, children, especially young children, are also more likely than adults to get severe complications of flu.
In Ireland, between 2009 and 2019, the HSE Health Protection Surveillance Centre reported 4,750 children who needed hospital treatment because of complications of flu, with 183 of these admitted to intensive care.
Symptoms of flu in children include high temperature, muscle pains, headache and fatigue.
