the surefire way to never get sick or catch a cold is just garlic, that's it.
have two spicy heavy garlic dishes a week and you will never get sick.
favorite way of doing this is a lunch of campbell's chicken soup with a clove of garlic microplaned into it fresh when the soup's hot.
haven't gotten sick in the last decade and a half since i started doing this, only called out of work in all that time for literal broken-leg-itis.