Dr. Theresa Tam, Canada’s chief public health officer, expressed her concern about the spread of COVID-19 variants, stressing that Canada has to be "extremely cautious" about lifting public health measures.
"My concern is that right now, if we release some of these measures, that a resurgence will occur," Dr. Tam said at a press conference on Tuesday. "That resurgence could be due to one of these variants and then it will be much more difficult to control."
Dr. Tam said that the B117 variant, initially detected in the U.K., "definitely" has a chance to be the variant that replaces all others.
"It's demonstarted an increased ability to transmit," she said. "That just makes it much more difficult to get under control."
Dr. Tam stressed that the impact of vaccines on transmission is still unknown at the moment, but she said if a variant is more transmissable, it could mean that a higher percentage of the population has to be vaccinated to acheive significant immunity in the community.
"Although it is normal for variants to emerge as viruses continuously evolve, these are considered variants of concern because they’re known to spread more easily," Dr. Tam said. "There is also a possibility of reduced protection of current vaccines."
"This is why we need to maintain the strictest vigilance in our public health maeusres and indivudal practices."
Dr. Tam said the good news is that we know what works, in terms of public health measures that can limit the spread of COVID-19, but she said a good "goal" for provinces to aim for is sequencing all positive test results to detect COVID-19 variants.