ANY DISCOUNT FOR SENIORS TO TAKE HK AIRPORT EXPRESS ?

As far as I know, there is no discount for the seniors, but they always have promotions for the airport express. For instance, the current promotion activities are: Buy One Get One Free Offer on the Airport Express Single Journey, Ticket for Visa Infinite and Visa Signature Cardholders, 4-person Group Ticket from HK$150, Morning Express Service, Airport Express "Ride to, Rewards" Programme and Airport Express Service Guide.
It is suggested to find more detail information on the official websites of MTR.