India has a very large and extremely heterogeneous population, and we need to know the efficacy on people across the country. Even the safety profile is unknown in such a diverse population. As we saw when Pfizer provided data on various ethnicities from its efficacy study, its mRNA vaccine had 74% efficacy among Asians and not the 95% seen overall. That tells you there are differences in efficacy, depending on ethnicity," said Davinder Gill, a vaccine expert based in Massachusetts, US, adding that vaccine developers need to conduct large scale trials in India as it is extremely diverse and heterogeneous.
