why wy?

This is from reputable medical site medscape.

In summary,
Upper respiratory tract illnesses and influenza-like illnesses are common, as is the use of home remedies and natural products to prevent and treat them.... It is prudent to ensure good hygiene, immunizations, adequate rest, and adequate fluid intake, while avoiding deficiencies of essential nutrients.

There is support for:
Echinacea. (Taken prophylactically, it can reduce the risk for URTI in adults by 58%)
Garlic
American ginseng
Pelargonium
probiotics in adults to prevent or treat URTI.

In children, some data suggest that vitamin C and echinacea can help reduce the risk for prolonged URTIs.

Although studies of black elderberry and andrographis are promising, no research has evaluated the optimal roles of these products with atypical H1N1 influenza infections.

Aside from common sense precautions (avoiding honey for children less than 1 year old to reduce the risk for botulism; avoid giving bacterial products to severely immunocompromised patients), natural products are generally very safe, and their use can be tolerated.