NEW DELHI : Variants of the novel coronavirus carrying two specific mutations in their spike protein may evade antibodies and make vaccines less effective, according to eminent virologist Shahid Jameel, who says the need of the hour is to improve surveillance for "homegrown" lineages of the virus.Jameel, Director of the Trivedi School of Biosciences at Ashoka University in Haryana, said these two mutations would lead to a "drastic change" in the structure of the part of the spike protein that binds with antibodies, making vaccines less effective against such variants.The spike protein of the coronavirus enables it to bind to the ACE2 receptor on host cells -- a process which studies have show to be crucial for the virus to enter the cells.