ALL-ROUND DEFENCE

► Multi-variant Covid-19 vaccine will have two or more strains of the Sars-cov-2 virus

► Such a vaccine will give better coverage against mutating viruses

► Currently, all Covid vaccines are based on the original Wuhan strain that started the pandemic

► The mixed vaccine approach may carry one Delta strain and at least one more strain

► Zydus is already working on a Delta variant of its DNA vaccine

► Govt institutions, too, are working on similar approach