Megastar Amitabh Bachchan, who has served as Unicef Goodwill Ambassador for the polio eradication campaign in India, says he is fortunate to be the top most influencer for the organisation.Amitabh on Tuesday shared a list of names of top influencers. "Among top 'influencers' for fight against polio, a list by Unicef. Privileged to be the top most influencer. Thank you UN!" Big B tweeted. The actor, 75, has been supporting and promoting various health and related issues such as childhood immunization programme, anti-tuberculosis campaign and the 'Clean India' initiative."Unicef Polio; World Polio Day, every child deserves to live a polio free life! I worked eight years on it and today India is polio free."On the acting front, Amitabh, who has wrapped up shooting for "Kaun Banega Crorepati", has two films in his kitty -- "Thugs Of Hindostan" and "102 Not Out".