India's decision to ban vaccine exports has had a severe impact on 91 nations dependent on Serum Institute of India's (SII) products, including the AstraZeneca vaccine (Covishield) and the forthcoming Novavax. With inadequate stocks, these countries, several of them in Africa, remain extremely susceptible to new strains of Covid, including B.1.617.2, first discovered in India, the World Health Organization (WHO) has said. "91 countries are impacted by the shortage of supplies, particularly since the AstraZeneca parent company has not been able to compensate for the doses which have not come from Serum," Dr Soumya Swaminathan, the WHO Chief Scientist, told NDTV.