Any vaccine maker, including Pfizer Inc, which has sought emergency-use authorisation for its COVID-19 shot in India, must conduct a local "bridging" safety and immunogenicity study to be considered for the country's immunisation programme, a senior government official told Reuters. Serum Institute of India, the local manufacturer of the vaccine developed by AstraZeneca Plc and Oxford University, has done a similar study on more than 1,500 people over months before seeking and receiving emergency approval in the country. Local media have reported that Pfizer had sought an exception when last month it became the first company to seek emergency-use approval in India for its vaccine already in use overseas.