Amid a surge in coronavirus cases, the race to get an approval for a vaccine is on across the world. More than a hundred vaccine candidates are being developed and tested. Russia has already approved a vaccine. We speak to Dr Paul Offit, an American pediatrician specialising in infectious diseases, vaccines, immunology, and virology. He is also the co-inventor of a rotavirus vaccine. According to him, it usually takes over 10 years to develop a vaccine. He explains the risks involved amid race to develop Covid vaccine.