12,000 college students sign up for COVID-19 spread test

As more and more Americans are getting vaccinated, researchers are looking to get a better sense of how vaccinated people will contribute to the spread of COVID-19.
About 12,000 students from 20 U.S. colleges are participating in a large study on the effectiveness of the Moderna vaccine.
Half the volunteers will receive the Moderna vaccine now, and the other half will receive it four months later.
Participants will be required to swab their nose on a daily basis and take a COVID-19 test twice a week.
Researchers are hoping to find out just how many people who are vaccinated will then get infected and spread the disease to others.