It truly depends on what caused the pneumonia and if it is truly pneumonia. I know many may disagree with this statement, but pneumonia is more of a combination of symptoms then a malady on to its self. To sum it up to the most simple explanation, pneumonia is a inflammation of the tissues of the lung. There are Many diseases in both humans and animals that cause pneumonia and frankly, some injuries (ie:trauma, poisoning) as well. There are also many diseases which seem to be pneumonia such as asthma or allergies (yes..animals can suffer form both).
So to answer your question...I don't know because it depends on what made the cat sick in the first place. There are a few...yes a few as in not a huge amount of diseases that spread from cats to humans, most only effecting humans if they are in a weakened immune state or pregnant. To be on the safe side get he cat checked if you haven't already. Handel the animal with care if it is yours (especially if it is not yours)...try not to come in direct contact with saliva, mucus, blood, etc. WASH YOUR HANDS above all else. This is an amazing method of diseases control that many humans seem to forget. Also clean your hands before you handle the animal because if it is that sick you may transfer something to the animal which could only attack it in it's weakened state. Also, be sure that this is pneumonia as many things such as poisoning or trauma can cause or mimic it. Hope this helps in so small amount. (experienced former Vet Tech & currently EMS...you would be surprised what they teach us now a day)

LOL i made it!