Send to Kindle The third coronavirus wave has subsided and we're leaving the zone of chaos, said mathematician and member of the now former National Operational Headquarters Prof. Nikolay Vitanov for the morning program of BNT. The prognoses are favorable, but we have to be wary and should not rely on the viral seasonality. The Indian version is on our borders and if we let it in, the period of calm will end, warned Prof. Vitanov adding that so far the favorable scenario for the development of the epidemic seems to be viable. At the moment, our shield against Covi-19 is becoming stronger and in 62-63 days we will achieve 70% of the built-up collective immunity. It is important, though, what will happen then– if we sit back and relax, the shield will get thinner, and again some subsequent infection surge may occur, the mathematician cautioned.