The Principal Scientific Advisor to the Prime Minister Wednesday said a third wave of Covid-19 was inevitable given the high levels of the circulating virus and that they couldn’t predict a time frame for it. Dr K V VijayRaghavan also admitted that experts had not anticipated the “ferocity” of the second wave currently sweeping the country. The PSA said the new variants now affecting people are “fitter”, had adopted a “hit and run lifestyle”, and required a new approach. About the reasons behind the second surge, the PSA said both the fact that the immunity from the first wave was not widespread and lowering of guard were responsible.