![](http://offroadtrucksxtreme.com/wp-content/uploads/2020/12/why-two-doses-of-the-new-covid-19-vaccines-are-better-that-one.jpg)
Many products featured on this site were editorially chosen. Popular Science may receive financial compensation for products purchased through this site.
Copyright © 2020 Popular Science. A Bonnier Corporation Company. All rights reserved. Reproduction in whole or in part without permission is prohibited.