This is a randomized, blinded, placebo-controlled, multicenter, parallel-group, dose finding 24-week study to assess the safety, tolerability and efficacy of up to 3 doses of BEZ235 alone and in combination with RAD001 as compared to placebo in elderly subjects who are at increased risk of respiratory tract infection related-morbidity and mortality. The study will be composed of up to a 6-week screening and run-in period, a 16-week treatment period and an 8-week follow-up period.