AstraZeneca said on Monday its COVID-19 vaccine could be around 90% effective, giving the world another weapon to fight the global pandemic. Professor Adrian Hill, who is overseeing the Oxford vaccine trials, tells NDTV," We have three pretty good vaccines -- all in the 90% range for efficacy. But we are not competing against each other; we are competing against the virus which has been winning for too long. These three vaccines give us a really good shot at fighting back."