By Ewen Callaway
Less than five months after the world first learnt about the new coronavirus causing fatal pneumonia in Wuhan, China, there are more than 90 vaccines for the virus at various stages of development, with more announced each week. At least six are already 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.
This typically involves giving thousands or tens of thousands of people a vaccine or placebo and seeing, over months or even years, whether there is a difference between the two groups in how many people get infected in the course of their daily lives, as well as checking that no safety issues emerge.
Continue reading by clicking the name of the source below.