Scientists in Canada and around the world are trying to solve a COVID-19 mystery — why have some people never tested positive, despite being exposed? And could they be genetically resistant to the virus?

#COVID19 #Immunity #CBCNews

Watch The National live on YouTube Sunday-Friday at 9 p.m. ET

Subscribe to The National:
https://www.youtube.com/user/CBCTheNa...

Connect with The National online:
Facebook |   / thenational  
Twitter |   / cbcthenational  
Instagram |   / cbcthenational  

More from CBC News | https://www.cbc.ca/news

The National is CBC's flagship nightly news program, featuring the day's top stories with in-depth and original journalism, with hosts Adrienne Arsenault and Andrew Chang in Toronto, Ian Hanomansing in Vancouver and the CBC's chief political correspondent, Rosemary Barton in Ottawa.