Try garlic, ginger, and turmeric... They all boost your immune system...
Use some black pepper with the turmeric as it boosts its effect over 1000 times...
Chop up some fresh garlic and add it to a pot of chicken noodle soup, you will start to feel it kick in by the time you finish the bowl...
Then cut a few small pieces of ginger and put them in a coffee cup with water... (ginger can get pretty strong quickly, so don't over do it)... Boil the water in the microwave with the ginger in it, then put your tea bag in and let the tea get strong... After the tea is saturated, add some honey and squeeze some fresh lemon in it... That will help and soothes your throat as well...