New Delhi, May 1 : Amid exponential rise in Covid-19 cases, India on Saturday started the third phase of vaccination drive covering those above the age of 18 years. However, the exercise began mainly in six states-- Maharashtra, Rajasthan, Uttar Pradesh, Chhattisgarh, Gujarat and Odisha. All other states and Union Territories (UTs) have either deferred vaccination for the age group of 18-44 by a few days due to shortage of vaccine. Even in these six states, the drive is "token", limited to just a few districts. The Centre has dubbed the drive as the Liberalised and Accelerated Phase-3 strategy of Covid-19 vaccination for which registration for the new eligible population groups commenced on April 28. Potential beneficiaries can either register directly on CoWIN portal (cowin.gov.in) or through the Aarogya Setu app. The exercise began at a time when many states are reporting shortage of vaccines on contrary to the Centre's report available till 8 a.m. on Saturday which has claimed that more than 79 lakh Covid vaccine doses (79,13,518) are still available with the states and Union Territories (UTs) to be administered. The Centre has so far claimed to have provided nearly 16.37 crore vaccine doses (16,37,62,300) to states and UTs "free of cost" of which the total consumption including wastages is 15,58,48,782 doses. Furthermore, the Centre has promised to provide more than 17 lakh (17,31,110) vaccine doses to the states and UTs within the next three days. Amid deadly Covid-19 second wave surge, the Centre had said that all Indian adults will be eligible to receive the Covid-19 vaccine starting May 1. The inoculation process and documents to be provided to get the jab to remain the same. It is to be noted that the government has made it mandatory for the 18-44 age group to register themselves on the CoWIN portal and get an appointment for vaccination against coronavirus, saying walk-ins will not be allowed initially to avoid "chaos" at immunisation centres once the inoculations drive opens up substantially. Though vaccines are to be available for all adults below 45 from Saturday, as per the Centre's new policy, this is contingent on states-- and not the Centre-- making them available to citizens. The Centre will continue to provide vaccines to states and vaccinate, for free, those over 45. States on the other hand have to negotiate with vaccine companies the price at which they will buy vaccines. This again will be from the 50 per cent of the vaccines that are made and cleared by the Central Drug Research Laboratory, Kasauli. The remaining will continue to go to the Centre for its programme. So far, Delhi, Kerala and Tamil Nadu have said they have ordered batches of Covaxin and Covishield. Close to 20 States have said they will be offering the vaccine free to their residents. Though vaccines for those below 45 can only be availed at private Covid-19 centres on payment, states and UTs can decide to vaccinate those below 45 from their quotas negotiated with companies by setting minimum age eligibility criteria. India has so far administered 15,49,89,635 doses since January 16 when the world's largest inoculation exercise started. /IANS