a recent Associated Press report.But scientists have never created a vaccine so quickly, and concerns about its effectiveness have arisen, as well.
Worldwide, testing has recently started or is about to start for about a dozen potential vaccines. The most promising vaccine candidates are expected to move into larger tests this summer, the AP said.How quickly those studies can determine whether the vaccines are safe and effective depends in part on how widely the coronavirus is still spreading.
The studies will need to enroll 20,000 people or more for each vaccine candidate, with half of them getting the real vaccine and the rest getting a dummy shot.