As Covid hospitalisations spike in Delhi, Soumya Swaminathan, the chief scientist of the WHO, tells NDTV the sub-variant found in the national capital is much more transmissible and evades antibodies as well. She said most of those hospitalised have not had their booster shot and everyone must do so immediately. She also said a second booster should be considered for the elderly and vulnerable and said several new vaccines are in the pipeline to fight all types of Covid variants.