The posts reccomending personel hygiene measures make a lot of sense and use of N95 masks can help during a flu outbreak. The idea that various homiopathic remidies strengthen the immune system is science fiction. There is no true scientific evidence these OTC herb suppliments provide any support for the human immune system.
The suppliment industry conned Congress into allowing the sale and advertising of these quack remedies without the FDA regulated testing required of ethical drugs.
Buy them if you like, it's your money, but no one should place any dependance on them.