[ Sign up for our Health IQ newsletter for the latest coronavirus updates ]Winnipeg police estimate roughly 15,000 people attended the #Justice4BlackLives rally on June 4, leaving little room for social distance as people peacefully protested for justice and equality. “You can go from zero to one to two cases to 100 in a blink,” said Carr.She said on the scientific and public health side, up to half the people that are infected don’t know it and the virus can be spread without the appearance of any symptoms.Carr asks people consider wearing a mask while attending protests.“The cloth mask approach now is another scientifically supported approach for you to do your part in stopping the spread..