EXPLAINER: Should vaccine volunteers now get the real thing?
Smartphone fitness apps and wearable activity trackers boost physical activity levels
21 December 2020France tightens virus curfew in several regions
1 January 2021EXPLAINER: Should vaccine volunteers now get the real thing?
Tens of thousands of Americans have volunteered to test COVID-19 vaccines, but only about half of them got the real thing during trials.
