The Centre for Cellular and Molecular Biology (CCMB) has discovered N440K variant, that might be responsible for creating havoc in Visakhapatnam and other parts of the State, experts said. Though it is too early to conclude that the new variant, which is being called the AP strain, is behind the huge surge in some parts of state.  The strain first discovered in Kurnool, is considered to be at least 15 times more virulent than the earlier ones, and may be even stronger than the Indian varian