A vaccine is seen as the most likely avenue for defeating the novel coronavirus and alleviating a worldwide health crisis that has killed at least 734,900 people and decimated national economies. Western regulators have said repeatedly that they do not expect a vaccine to become widely available before the end of the year at the earliest.
Around the world, more than 30 vaccines — out of a total of more than 165 under development — are now in various stages of human trials. Currently, eight vaccines have entered the final phase of mass human testing, including ones produced by Moderna in the United States, Oxford University and AstraZeneca in Britain and several Chinese companies.