New Delhi: At least 447 persons reported adverse effects after covid-19 vaccination with majority complaining fever, headache and nausea, according to the provisional data of ongoing vaccination drive.An Adverse Event Following Immunization (AEFI) is any unexpected medical occurrence which follows immunization which may not be related to vaccine or vaccination process.India has granted emergency use authorisation (EUA) to two covid-19 vaccines -- Pune-based Serum Institute of India’s Covishield and Hyderabad-based Bharat Biotech International Ltd’s Covaxin which are being used in the government’s vaccination drive.“A total of 447 AEFI have been reported so far.