Scores of coronavirus vaccines are in competition — how will scientists choose the best?

Scores of coronavirus vaccines are in competition — how will scientists choose the best?

How to choose the best vaccine More than 90 vaccines for the coronavirus are at various stages of development, and at least six are being tested for safety in people. Now, developers, funders and other stakeholders are laying the groundwork for their biggest challenge yet: determining which vaccines actually work. The World Health Organization has proposed an adaptive trial design that allows vaccines to be added and dropped on an ongoing basis. The agency still has to work out which vaccines to test first, and how to convince drug developers to have their products pitted against each other. Large trials are usually necessary to determine safety and efficacy. An alternative is to administer vaccines that look safe in early-stage trials to high-risk groups — such as health-care workers — under ‘emergency use’ rules. Nature | 7 min read