When could a COVID-19 vaccine be ready? Top health officials say the end of this year would be a best case scenario.
But there’s no guarantee the vaccine candidates under development will ultimately work.
Worldwide, testing recently started or is about to start for about a dozen potential vaccines.
How quickly those studies can determine whether the vaccines are safe and effective depends in part on how widely the new coronavirus is still spreading. Vaccines work by training the body to recognize a virus, which in turn prompts it to produce antibodies to fight the virus.