I'm asthmatic and at least once a year I get a cold which turns into a nasty chest infection, makes me feel really grim and needs antibiotics to clear it. Well am now on second bout this winter and desperate. How can I avoid catching colds in the future? Already take 1000mg vitamin C plus zinc plus multivitamin throughout the cold season, eat healthy diet with lots of organic fruit and veg, have tried echinacea but it didn't work for me. Anybody got any alternative remedies they can recommend to help my immune system please, please, please.