California Healthline July 16, 2020
Louis Jacobson, PolitiFact

More than four months into the coronavirus pandemic, how close are the U.S. and the world to a safe and effective vaccine? Scientists say they see steady progress and are expressing cautious optimism that a vaccine could be ready by spring.

As of early July, roughly 160 vaccine projects were underway worldwide, according to the World Health Organization.

Generally, a vaccine trial has several phases. In an initial phase, the vaccine is given to 20 to 100 healthy volunteers. The focus in this phase is to make sure the vaccine is safe, and to note any side effects.

In the second phase, there are hundreds of volunteers. In addition to monitoring safety, researchers try to determine whether shots produce an...

2020-07-16T18:31:23-04:00