CHMP5 and infection: This probably could be as both Delta and BA.4/ BA.5 share the L452R mutation on the receptor-binding domain (RBD) of spike protein, the convalescent sera from Delta infection may contain L452R-specific neutralizing antibodies, which could have impaired the BA.4/ BA.5 transmission in India [18]. Also, BA.2.75 has shown 57-fold higher binding affinity to ACE2 receptors when compared with BA.5, accounting for its higher transmissibility [19].