Doctor testing new vaccine says there's long way to go

Study subjects who received Moderna's Covid-19 vaccine had positive early results, according to the biotech company, which partnered with the National Institutes of Health to develop the vaccine. Dr. Carlos del Rio, who is working on the vaccine trial, explains what steps are still to come.

Doctor testing new vaccine says there's long way to go
Study subjects who received Moderna's Covid-19 vaccine had positive early results, according to the biotech company, which partnered with the National Institutes of Health to develop the vaccine. Dr. Carlos del Rio, who is working on the vaccine trial, explains what steps are still to come.