Can garlic boost the immune system?

Can Garlic Boost the Immune System?

Can garlic boost the immune system? (Things you learn when ordering coffee).
 
Each day on the way to work I would stop by and order my regular coffee from the country's best barista (in my opinion). He was a friendly and likeable bloke who enjoyed giving out advice at every opportunity. One day while I was under the weather with the man flu, he threw me a head of garlic and suggested I take a clove a day. Not too sure what to think, I took his advice with a grain of salt. Does garlic actually work for the common cold, or should it be reserved for vampires instead?
 
Interestingly, a Cochrane meta-analysis was conducted with the aim of answering this question (for common cold that is, not vampires). The review identified a single randomised, double-blind, placebo-controlled trial involving 146 volunteers and found that a garlic supplement taken each day for 12 weeks resulted in fewer days of illness in the garlic group compared to placebo (111 vs 366 days; p value < 0.001) suggesting that garlic might prevent occurrence of the common cold. While more studies would be required to validate this finding, there doesn't yet seem to be any evidence to suggest my barista was wrong. Maybe next time I'll ask for a garlic-infused coffee!