Union Health Minister Harsh Vardhan said on Monday that 18-19 potential vaccines against novel coronavirus were in different stages of clinical trials, adding that vaccination of around 27 crore Indians above the age of 50 will begin three weeks from now."Some are in Phase I, some in Phase II, and a few approaching Phase III of the clinical trials. We are elated to have a huge portfolio in the near future," he said at a press conference here.The Minister said that the Department of Biotechnology had been provided a budget of Rs 900 crore for the development of potential vaccines against Covid-19."The money has been kept aside for the department for use in research and development of potential vaccine candidates against the viral disease," he added.Vardhan also said that the Union government will begin vaccination drive for around 27 crore Indians above the age of 50 three weeks from now."Three weeks from now, the government will start giving doses of coronavirus vaccines to 27 crore persons above the age of 50," he said.An expert group on vaccination will discuss how to pay for the doses for those above 50, he added.The vaccination for frontline workers began earlier this month.On the private healthcare sector's role in the vaccination process, he said that such facilities and workers were already a part of the drive."During emergency use authorisations (EUA), it is the government's responsibility to keep things under control; open market sales are not part of the EUA," he added.Meanwhile, the Minister reviewed the Covid-19 situation in the country. He said that no new cases of COVID-19 have been reported in 188 districts of the country in the past seven days.Vardhan emphasised the importance of social distance and appropriate healthcare behaviour amid the pandemic despite falling number of corona cases in the country."It is crucial that people continue to follow COVID-appropriate behaviour which I had called a social vaccine, along with the real vaccine," he quipped.Meanwhile, the Health Ministry said that a new flagship programme -- Prime Minister Atmanirbhar Swastha Bharat Yojana -- has been announced in the Union Budget 2021-22. "The Budget refers to a holistic approach toward health and healthcare. Allocation to the health sector for 2020-21 is 1.8 per cent of the Gross Domestic Product," the Ministry added.The Union government has prioritised vaccination of 30 crore Indians, dividing them into three categories -- one crore healthcare workers, 2 crore frontline workers, and 27 crore general populace above the age of 50.On January 3, the Drugs Controller General of India had approved 'Covishield' vaccine developed by Pune-based Serum Institute of India and 'Covaxin' of Bharat Biotech for emergency use authorisation in the country.Both vaccines have been provided in the nationwide immunisation drive, that was kicked off on January 16. Till Sunday, more than 8 million (82,85,295) doses of vaccines had been administered across India.