The Corona Virus pandemic is far from over and the world will have to wait for a couple of months . The new single-dose vaccine has shown to be 66% effective against Covid-19, and offered complete protection against hospitalisation and death in trials .However, there are signs the jab, made by Belgian pharmaceutical firm Janssen, is less effective against the new variant spreading in South Africa. Crucially, no one needed hospital treatment or died from coronavirus after the Janssen vaccine took effect in the international trial. The vaccines are proving to be expensive for the poor countries, how many doses do we need per individual ?