Serum Institute of India (SII), which makes the most used COVID-19 vaccine in the country, on Saturday defended pricing Covishield vaccine at 1.5 times the initial rate, saying the earlier price was based on advance funding and now it has to invest in scaling up and expanding capacity to produce more shots. The world's largest vaccine maker, which manufactures Oxford-AstraZeneca vaccine at Pune, earlier this week announced a price of Rs 600 per dose for private hospitals and Rs 400 per dose for state governments and for any new contract by the central government. It currently charges the Union government Rs 150 per dose for the existing supplies. Here are three points the II made in defence of the recent announcement made to increase the price of the vaccine: > Addressing opposition parties and critics of Covishield’s new rate sheet, the SII said that there was an “inaccurate comparison” done between the global prices of the vaccine with India. "Covishield is the most affordable COVID-19 vaccine available in the market today," the SII’s statement said. > The initial prices were kept very low globally as these were based on advance funding given by those countries for at-risk vaccine manufacturing, it added. Government procurement for countrywide immunisation programmes in all countries, including India, has been at a far lower price as the volumes are very large, the statement further read. > The SII defended the increase in its vaccine prices by stating that the company has to ensure sustainability. "The current situation is extremely dire; the virus is constantly mutating while the public remains at risk. Identifying the uncertainty, we have to ensure sustainability as we must be able to invest in scaling up and expanding our capacity to fight the pandemic and save lives,” it said. The company went on to add that only a limited portion of SII's volume will be sold to private hospitals at Rs 600 per dose. "The price of the vaccine is still lower than a lot of other medical treatment and essentials required to treat COVID-19 and other life-threatening diseases", it added. Earlier this week, Serum Institute had said, "Going ahead, 50% of our capacities will be served to the government of India's vaccination program, and the remaining 50% of the capacity will be for the state governments and private hospitals." The government on Saturday exempted basic customs duty on import of COVID vaccines, medical-grade oxygen and related equipment for three months with immediate effect to boost their availability and make them cheaper amidst rising cases of coronavirus infections in the country.