The minister of state for health Bharati Pravin Kumar has told the parliament that no fixed timeline can be indicated for the completion of the COVID-19 vaccination drive.However the government expects that all people above the age of 18 will be vaccinated by December this year -- the statement is a part of her written reply to a list of questions put forward by Congress leader Rahul Gandhi.Regarding the question on availability of vaccine doses, the junior minister says that 135 crore doses are expected to be available between August and December 2021.To the question regarding a delay in entering advance purchasing agreements with vaccine manufacturers, the minister responded by saying there have been no delays and that advance payments have also been made to manufacturers for supply orders placed with them. So far Rs 9,725 crore has been spent on the COVID vaccination drive, according to the reply in parliament.In an interview with CNBC-TV18's Shereen Bhan, Dr Anurag Agrawal, Director of CSIR-IGIB said, "In many places sero positivity is still not very high and that means there are vulnerable cases. However what is nice is that the deaths are coming down. Right now we are in the fag tail of the second wave but nothing very alarming as of now."He also expects the third COVID wave to be mild."Once people have been infected, it is rare to get severe disease the second time. It can happen but it is very uncommon. Also once a person has been vaccinated, it is difficult to get severe disease although it does happen from time to time. The sero positivity of India is at 66.7 percent on the national sero-survey and the vaccination is also climbing. So when I combine all these together it leads me to the conclusion that the third wave would be mild with the exception of two possibilities - first the virus changes substantially and creates more severe disease and the second possibility is if we end up having super spreading events."Watch video for more.