Can alcohol contribute to lung infections?

Often does...: ...Mainly by causing people to aspirate (inhale their own vomit), and by suppressing immunity through malnutrition.

Yes, indirectly: When people drink heavily, they will fall asleep, but if the sedation is severe enough, they will not be able to handle the secretions that build up in their mouths and may aspirate these, which is a cause of pneumonia. Alcohol also affects the immune system, and alcoholics get pneumonia sometimes with very strange germs, like klebsiella they also get more tuberculosis and mycobacterial infections.