Credit: Babble

Drug regulators are immediately investigating the flu vaccine used for children to check for its safety following the announcement by Australia's chief medical officer to halt immunization for children under five years of age.

The announcement was called after an increase number of Western Australian children were admitted to the hospital suffering from fever and convulsions after receiving the flu shots.

According to a spokesperson from the Therapeutic Goods Administration (TGA), the move is a precautionary measure while the issue is being urgently investigated by health experts.

The drug regulator is seeking to assess whether the bad reactions reported in Western Australia are associated with the vaccine or whether the problem arises from the way it is being administered.

The inquiries into the health concern are also being conducted by the Department of Health and Ageing.

All states and territories are advised to report any cases of fever or convulsion following vaccination to the TGA.