Indian Prime Minister Narendra Modi on Saturday rolled out the world’s largest national vaccination drive against the Covid-19 pandemic, initially covering some 300 million vulnerable people from its mammoth 1.4 billion population. Mr Modi flagged off the drive virtually via his YouTube channel while praising India's scientists and health workers for their work in dealing with the disease that has killed more than 150,000 people in the country, battered its economy and left tens of millions without livelihoods. “We have got two vaccines in such a short time, it's a testimony to our scientists' talent and skills,” he said. India this month approved the use of two vaccines for emergency use, both of which will be produced locally. The vaccine developed by Oxford University and AstraZeneca will be distributed under the name Covishield, while the other developed by the Indian company Bharat Biotech is branded Covaxin. Covaxin is yet to complete its Phase 3 human clinical trials. About 300,000 people are expected to be vaccinated at more than 3,000 centres across the country on the first day. Many vaccination centres were decked with balloons and flowers and staff cheered and clapped as the immunisations began. A sanitation worker at a New Delhi hospital was the first person to be vaccinated in the country. “I feel very happy after taking the shot,” worker Manish Kumar told reporters after receiving the shot at the All India Institute for Medical Sciences in the Indian capital. Authorities plan to inoculate 10 million doctors, nurses and other hospital workers in the initial phase. About 300 million people – almost equal to the entire US population – from priority groups that include health workers, people over 50 and those deemed at high-risk such as diabetics, will be inoculated free of cost by June in the first stage of the immunisation plan. “Our vaccination programme is driven by humanitarian concerns, those exposed to maximum risk get priority,” Mr Modi said. "This disease kept people away from their families. The mothers cried for their children. People could not meet their elderly admitted at hospitals. We could not bid adieu to those with proper rituals who died," he said. Mr Modi warned his countrymen not to lower their guard against the disease and to follow preventive protocols such as wearing masks and social distancing. India is the second worst-affected country behind the US with about 10.5 million cases of Covid-19 so far. But infection rates have dropped considerably, from a peak of about 100,000 cases a day in September to more than 15,000 cases on Saturday. However, concerns remain over another wave of infections, including with new virus strains such as the one that emerged in the UK which has infected 116 people in India. At New Delhi’s Lok Nayak Jai Prakash Hospital, there was an air of jubilation among the staff after months of battling the pandemic. The hospital has treated more than 10,000 Covid-19 patients since India's coronavirus outbreak began a year ago. The heavily guarded hospital was festooned with balloons and garlands and a red carpet had been spread out to welcome the nearly 100 frontline workers who were to be vaccinated on day one. Doctors, nurses and technicians eagerly waited for their turn in a large hall as officials in protective gear administered the vaccine in a side room and handed a red rose to each recipient, some of whom flashed victory and thumbs-up signs. "I feel elated and privileged to have been vaccinated as one of the frontline workers. I have not experienced any side effects so far and I am looking forward to the second dose," one of the vaccine recipients told <em>The National</em>. But at some centres recipients were asked to sign consent forms before taking the indigenously developed Covaxin vaccine that the government approved for emergency use in “clinical trial mode” as its Phase 3 human trial has yet to be completed. The approval sparked controversy, and reports emerged of shoddy clinical trials in the central city of Bhopal where trial subjects were denied consent papers and medical care. A Delhi hospital doctors' association on Saturday expressed safety concerns over Covaxin and demanded they be given the Covishield vaccine instead. The government has dismissed such concerns and asked the public not to be misled, saying both the vaccines were safe and effective. India is using its vast experience from previous public immunisation drives, such as for polio, in the coronavirus vaccination campaign. National and local electoral rolls are being used to enlist recipients and a newly developed mobile application, CoWin, will be used to monitor the two-dose vaccinations. Armed guards have been assigned to secure millions of vials of vaccine kept at nearly 30,000 cold storage warehouses. Some 100,000 deep freezers, refrigerators and solar-powered coolers are being used to keep the vaccines at the required temperature of between 2 and 8°C. The government has already procured nearly 16 million vaccine doses from the two manufacturers and will be buying nearly 60 million more in coming weeks. At least five more vaccine candidates are undergoing clinical trials in India and are likely to get government approval by March this year.