There are other infections that have been implicated. Epstein-Barr Virus and human herpes virus-6 (HHV-6) are other suspects. We all can improve our natural immune function primarily by keeping vitamin D level AT or ABOVE 125nmol/l or 50ng/ml with around 1000 iu daily vitamin D3 for each 25lbs we weigh.
In order to activate the circulating form of vit d into the hormonal form requires magnesium so ensuring our daily magnesium intake is at or above the RDA for magnesium can only help.
Magnesium is also fundamental to the production of MELATONIN which is also a natural antibiotic and fundamental to immune function. Both Vitamin D3 and Time release melatonin are cheap to use as supplements and restoring the natural levels we would have produced when humans lived outdoor lives and didn't have electric lights is both safe and sensible.
Our immune function is also helped by our gut flora. Anyone who has ever had an antibiotic, was born via C Section, wasn't breast fed, will not have optimum diversity of gut flora. We can improve gut flora with regular use of home made yoghurt or kefir and fermented foods. but it should be regarded as an ongoing long term strategy Dr Art Ayers on repairing gut flora
I have to self catheterise because my bladder doesn't connect to my brain so I was constantly having UTI and spent several years on antibiotics before I raised vit d, sussed out the magnesium/melatonin connection and improved gut flora. I've now been UTI free (touch wood) for several years so am confident that everyone can achieve the same immune function and live antibiotic free and not require flu jabs to avoid seasonal infections. The key factor is getting 25(OH)D above 125nmol/l and keeping it above that threshold.