Oleander would be a good immune system stimulator to help prevent pneumonia in the future as well as help shorten its severity and duration if you did perchance get it.  I am not sure how much you could expect it to help once you actually have pneumonia.  As a preventive I would suggest a month of 1 capsule twice a day and then cutting back to a capsule every day or two.  And keep in mind that there is no subsitute for building a good health foundation to begin with. Otherwise you may just be putting a good supplement on top of an unhealthy diet and lifestyle and not get anywhere near the results that you might otherwise receive.