Even as India's first indigenous coronavirus vaccine Covaxin is entering its third phase of human trials, Bharat Biotech on Monday raised the logistical query on "how to vaccinate 1.3 billion (130 crore) people with two injectable doses. Terming the exercise a "challenge" it also said that work was on single-dose nasal drop vaccine.Bharat Biotech International Limited (BBIL) Chairman and Managing Director Krishna Ella said the company's Bio-Safety Level 3 (BSL-3) facility currently has limited capacity but hoped to reach one billion (100 crore) doses by next year."We have partnered with ICMR (Indian Council of Medical Research) for Covaxin and as we speak, we are entering phase III trials but I am not happy because it is a two-dose injectable vaccine. If we have to vaccinate 1.3 billion population with two dose vaccine, we need 2.6 billion (260 crore) syringes and needles," he said.Ella was addressing Deccan Dialogue organised by the Indian School of Business (ISB) and supported by the Ministry of External Affairs (MEA) on 'Crisis and cooperation: Imperative in the times of pandemic'."We are working on another vaccine, a single dose nasal drop. We have experience of making Rotavirus and Polio nasal drop vaccines. We can scale up to 1 billion doses and my feeling is that by next year we will reach there," he said.The Hyderabad-headquartered vaccine maker announced in September that it is collaborating with the Washington University School of Medicine in St Louis, Missouri to manufacture a billion doses of a single-dose intranasal vaccine."The challenge is to vaccinate 1.3 billion population. Six billion (600 crore) people in the developing world have to be vaccinated but the opportunity is if 20 per cent of them are vaccinated, I have done my job as a scientist. You partly need vaccine because there will be herd immunity," he added.Ella also pointed out that 40,000 unknown viruses are existing. "10,000 viruses can hop from animal to animal and to human. What we are seeing today is only a sample. Because of its impact on economy it got more attention. We are yet to see lot many things."Indian Institute of Technology (IIT), Hyderabad's Prof M. Vidyasagar, who is also the chairman of the 'COVID-19 Indian National Supermodel Committee', however, said for this pandemic 30 to 40 per cent people needed to be vaccinated to achieve herd immunity."The challenge is whether the cold weather especially in north India exacerbate this pandemic and whether we can predict this by observing the course of the pandemic," he said.He noted that India had more success in controlling the pandemic unlike other countries like the US, the UK and France who have death rate per million 7 to 8 times higher than that of India."These countries have gone back to second lockdown because they see so-called second wave. This raises the question could proper modeling have helped these countries to foresee that there will be second wave, whether it could have helped the countries to assess effectiveness of the first lockdown, would the second lockdown be more effective this time when it was apparently not successful the last time," said Prof Vidyasagar.Arti Ahuja, Additional Secretary, Ministry of Health and Family Welfare, said India should be proud of what it has done to deal with the pandemic.She said from just one public health institute conducting COVID-19 test, the country now has 2,000 laboratories. According to her, it was not just the government but the participation of all stakeholders, including the private sector which helped the country deal with the pandemic.Rahul Chabra, Secretary, Economic Relations, Ministry of External Affairs, said the pandemic brought out new aspects of non-military threats to the security. Health security came up as major issue and multilateral cooperation now has to be part of strategic foreign policy engagement with all countries.Vikram K. Doraiswamy, India's High Commissioner to Bangladesh, Prof Sarang Deo, Executive Director, Max Institute of Healthcare Management, ISB also addressed the session, which was moderated by Govindraj Ethiraj, Founder, IndiaSpend and BOOM.