The US-based multinational pharmaceutical company, Pfizer has sought a fast-track approval for its Covid-19 vaccine. It has told Indian authorities that its jab has shown "high effectiveness" against the SARS-CoV-2 variant prevalent in India and on people of Indian ethnicity or nationality, while it is suitable for everyone aged 12 years or above and can be stored for a month at 2-8 degrees, sources said on Wednesday.