Vaccine Watch: How far away are COVID-19 booster shots?
ABC News’ Bob Woodruff looks at how Pfizer and Moderna are developing booster shots to target virus variants. SUBSCRIBE to ABC NEWS: https://bit.ly/2vZb6yP Watch More on http://abcnews.go.com/ LIKE ABC News on FACEBOOK https://www.facebook.com/abcnews FOLLOW ABC News on TWITTER: https://twitter.com/abc
