As Hyderabad-based pharmaceutical major Dr. Reddy's Laboratories (DRL) announces it has received permission from the Drugs Controller General of India (DCGI) to import Sputnik V vaccine in India for restricted use in emergencies, here are a few things that you need to know about the Covid-19 jab.After Covishield and Covaxin, Sputnik V, developed by Gamaleya National Research Institute of Epidemiology and Microbiology in Moscow, is now the third Covid-19 vaccine to get emergency use approval in India.According to the guidelines, the vaccine is indicated for active immunisation to prevent Covid-19 in individuals more than 18 years old and it needs to be stored at minus 18-degree Celsius in its liquid form.However, it can be stored at 2-8 degree C in its freeze-dried form in a conventional refrigerator, making it easier to transport and store.In a recent study, published in the journal The Lancet, the efficacy of Sputnik V was determined to be 91.6 per cent."There is a need to generate evidence about its efficacy in the Indian population. Sputnik V will provide one more option to the country to boost its vaccination drive," Harshal R Salve, Associate Professor at Centre for Community Medicine, All India Institute Of Medical Sciences (AIIMS), New Delhi, told IANS.According to Neha Gupta, Infectious Diseases Specialist at Medanta - The Medicity, Gurgaon, Sputnik V is a viral vectored vaccine and is likely to perform similar to Covishield.The vaccine should be administered in two doses of 0.5 ml each with an interval of 21 days.While talking to IANS, Indian Council of Medical Research's N.K. Arora said that the composition of the first dose will be different from the second dose and there should be at least a three to four weeks gap between the first dose and the second.Sputnik V is approved to tackle Covid-19 in 60 countries across the world, including ranking second among Covid-19 vaccines globally in terms of the number of approvals issued by the government regulators.The emergency approval for Sputnik V comes amid reports of vaccine shortage in some states even as cases have increased dramatically over the past few days.On Monday, the Union Health Ministry said that nearly 30 lakh doses of Covid-19 vaccine were given on Day 1 of the "Tika Utsav" which has pushed the cumulative coverage to 10.45 crore, as India's average doses per day crossed the 40 lakh mark, continuing to be the highest globally.In terms of number of cases, data from Johns Hopkins University (JHU) showed that India has overtaken Brazil, which is now at the third spot in the Covid-19 tally with over 1,34,82,023 cases.