Is this just weakened immunity? or is influenza/pneumonia bug still in my system years later?

in 1999 i travelled to sydney city in australia for 6 months holiday/work, but I contracted possible influenza and pneumonia (the infection was bad: copious mucous, delirium, fevers, chest and throat pain & laboured breathing, shivers, etc. but not vomiting). i had taken the flu jab 5 years consecutively previous to my trip, but on the year of my trip I didn't have one. influenza A was reported to be circulating in this city in July/winter time when I contracted illness. on the plane home my eardrum was perforated. after a throat swab was taken i was told i had a respiratory infection. one year after unsuccessful atempts to eradicate repeated bouts from my system, i took two courses of Viral-Ex and the core virus symptoms seemed to disappear. However, annually since 1999 I have suffered from at least one 'lesser' infection of the 'flu' for example ear-ache or coughing - there is always mucous in my pages. is there a way to be rid of these re-infections for good?