When Can We Expect A Coronavirus Vaccine?

Most health experts agree that the need for a vaccine to prevent COVID-19 is clear.

"To return to a semblance of previous normality, the development of SARS-CoV-2 vaccines is an absolute necessity" is how a perspective in Science magazine puts it.

So it's hardly surprising that, around the world, anticipation is high. With more than 100 coronavirus vaccines under development, researchers are reasonably confident that at least one will be successful. Skeptics, and there are some, remind us that optimism about an AIDS vaccine was once high, and 40 years later there is no vaccine.

Still, even if experts today are right that a vaccine for COVID-19 will be easier to develop than an AIDS vaccine, estimates for when it will be widely available vary. Here are some of the vaccine-related questions being raised — and