Megastar Amitabh Bachchan is planning to start a new campaign for infectious disease caused by the hepatitis B virus (HBV). The 72-year-old actor, who is also a UNICEF Global Ambassador for polio eradication, met doctors recently to strategies the plan. Amitabh Bachchan posted on twitter: T 1720 - Wish to start a campaign on awareness of HepatitisB .. met some committed doctors and shall strategise .. detect and cured asap ! — Amitabh Bachchan (@SrBachchan) December 29, 2014 Apart from his social works, Bachchan is also excited to release the first song of his upcoming release 'Shamitabh' after unveiling the film's first audio poster. Amitabh Bachchan tweeted: T 1721 - #Shamitabh . !!!! next for the song of the film .. wait wait wait .. youseethewholecountryofthesystem ..!! pic.twitter.com/xjKivbUR3s — Amitabh Bachchan (@SrBachchan) December 29, 2014 Besides Bachchan, the R Balki-directed film stars Dhanush and debutante actress Akshara Haasan. It is expected to hit theatres on February 6 next year.