Exclusive: U.S. plans massive coronavirus vaccine testing effort to meet year-end deadline

FILE PHOTO: Small bottles labeled with a "Vaccine COVID-19" sticker and a medical syringe are seen in this illustration taken taken April 10, 2020. REUTERS/Dado Ruvic/Illustration/File Photo

CHICAGO (Reuters) - The United States plans a massive testing effort involving more than 100,000 volunteers and a half dozen or so of the most promising vaccine candidates in an effort to deliver a safe and effective one by the end of 2020, scientists leading the program told Reuters.

The project will compress what is typically 10 years of vaccine development and testing into a matter of months, testimony to the urgency to halt a pandemic that has infected more than 5 million people, killed over 335,000 and battered economies worldwide.