As the virus gets better at spreading, our vaccination rates will have to be even higher to make sure those who can’t get a jab can still be kept safe, Dr. Supriya Sharma said.

Manaus Mayor Arthur Virgilio blamed right-wing President Jair Bolsonaro, who has minimized the gravity of the pandemic, for encouraging a return to normal life and work instead of waiting for a vaccine to be developed.

What is herd immunity and what does it mean for this novel coronavirus? Here's what experts say.