Seasonal flu risk--benefit/IBT Australia

Why so many reactions following seasonal flu vaccination?  Some have suggested it is due to children who had had earlier, subclinical flu infections.  Such silent infections would have left them with robust immunity.  They may then have responded to vaccination with an excessive response, triggering fever, convulsions and potentially death.  This idea remains a theory at this time.

Professor Peter Collignan points out that in a report on childhood swine flu vaccinations published in JAMA, 35% had fever. That seems rather high.  According to IBT Health, Australia:

The deputy director of the National Centre for Immunization Research and Surveillance, Kristine Macartney said more reactions were reported in Western Australia because it was the only state to have a policy of immunizing all children under five with the seasonal flu vaccine.


"Western Australia are immunizing many more young children than other states and territories, where children [elsewhere in Australia] are only recommended to have the vaccine if they are in a high-risk group," she said.

After receiving immunization, she observed that up to 40 per cent of children will develop elevated temperature and 3 per cent of children will have febrile convulsions at some stage.

Flu vaccines are only expected to provide immunity for a few months to a year.  So that is a lot of adverse reactions for a small benefit, especially when you take into account that most infections are silent [asymptomatic].  And convulsions are potentially life-theatening.  Who performed the risk-benefit calculation for this vaccine?  What is the precise makeup of the vaccine?  I will have more on this later.