Can drink beer before vaccine

I just came back from Travel Health Center and tomorrow I am going to take 4 vaccination shots due to a business trip which will take me to Africa. The doctor has decided to postpone my session because the day before I have been drinking too much beer. He advised me to strictly refrain from drinking beer either before and 24 hours the vaccinations....

I think all doctors by nature have their own evils about smoking and drinking and they tend to exagerate. I don't think that drinking a couple of beers is going to make a difference but since I am not too sure, at this time I prefer not to risk and stick to the doctor's advice...