Statement from the Chief Public Health Officer of Canada on June 7, 2021

OTTAWA, ON, June 7, 2021 /CNW/ - The Public Health Agency of Canada (PHAC) uses a variety of tools to detect and monitor the SARS-CoV-2 virus that causes COVID-19, including monitoring for early indications of community spread. Testing wastewater is a non-invasive approach that enables the efficient monitoring of a population for early warning signals of COVID-19. PHAC works in collaboration with other federal departments, provincial, territorial and municipal governments and academia to establish a pan-Canadian wastewater surveillance network to monitor early warning signals of SARS-CoV-2 circulation in communities.

Early detection of the virus in wastewater may provide a 5 to 10 day early warning, allowing important intervention opportunities to interrupt further spread of COVID-19, before a large number of cases are reported in the community. In Canada, wastewater surveillance is contributing to public health action and interventions in several jurisdictions.

In Northwest Territories, for example, a positive COVID-19 signal detected in the city's wastewater led to the identification of COVID-19 infection in an individual who was quarantined in Yellowknife. Through further surveillance, more positive samples were identified, suggesting other cases were present in the community, which prompted a press release asking quarantining community members to get tested. Taking quick action, based on wastewater surveillance signals, led to the identification of additional cases, which prevented a potential outbreak.

In addition, PHAC also conducts whole genome sequencing of wastewater samples. This provides current information on circulating variants of concern (VOC) and variants of interest (VOI), as well as insight into potential emerging VOCs/VOIs. This is particularly useful in detecting VOC/VOI that may be carried by asymptomatic individuals, which can be potentially missed by the clinical case-based surveillance. The ongoing expansion of wastewater surveillance networks will continue to be an important tool for the COVID-19 response, with benefits extending beyond COVID-19 to address other public health issues of concern such antimicrobial resistance and foodborne pathogens.

As COVID-19 activity continues in Canada, we are tracking a range of epidemiological indicators to monitor where the disease is most active, where it is spreading and how it is impacting the health of Canadians and public health, laboratory and healthcare capacity. At the same time, the Public Health Agency of Canada is providing Canadians with regular updates on COVID-19 vaccines administered, vaccination coverage and ongoing monitoring of vaccine safety across the country. The following is the latest summary on national numbers and trends, and the actions we all need to be taking to reduce infection rates, while vaccination programs expand for the protection of all Canadians. Due to reduced reporting over the weekend, national seven-day averages have not been updated in today's statement. These data are still being collected and analysed. I will provide the latest numbers during my remarks tomorrow.

Since the start of the pandemic, there have been 1,392,563 cases of COVID-19 and 25,724 deaths reported in Canada; these cumulative numbers tell us about the overall burden of COVID-19 illness to date. They also tell us, together with results of serological studies, that a large majority of Canadians remain susceptible to COVID-19. However, as vaccination programs expand at an accelerated pace, there is increasing optimism that widespread and lasting immunity can be achieved through COVID-19 vaccination over the coming weeks and months.

As immunity is still building up across the population, public health measures and individual precautions are crucial for COVID-19 control. Thanks to measures in place in heavily affected areas, the strong and steady declines in disease trends continues. The latest national-level data show a continued downward trend in disease activity with an average of 2,339 cases reported daily during the latest 7 day period (May 28-June 3), down 31% compared to the week prior. For the week of May 23-29, there were on average of 78,089 tests completed daily across Canada, of which 3.8% were positive for COVID-19, compared to 4.7% the week prior. Until vaccine coverage is sufficiently high to impact disease transmission more broadly in the community, we must sustain a high degree of caution to drive infection rates down to a low, manageable level, and not ease restrictions too soon or too quickly where infection rates are high.

With the considerable decline in infection rates nationally, the overall number of people experiencing severe and critical illness is also declining. Provincial and territorial data indicate that an average of 2,344 people with COVID-19 were being treated in Canadian hospitals each day during the most recent 7-day period (May 28-June 3), which is 19% fewer than last week. This includes, on average 1,006 people who were being treated in intensive care units (ICU), 14% fewer than last week. Likewise, the latest 7-day average of 34 deaths reported daily (May 28-June 3) is declining, showing a 21% decrease compared to the week prior.

Canada is continuing to monitor and assess genetic variants of the SARS-CoV-2 virus, including impacts in the Canadian context. Overall, variants of concern (VOCs) represent the majority of recently reported COVID-19 cases across the country. The World Health Organization has established new simplified labels for variants of concern using letters of the Greek alphabet. Four VOCs (B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), and B.1.617, which includes B.1.617.2 (Delta)) have been detected in most provinces and territories, however, the Alpha variant continues to account for the majority of genetically sequenced variants in Canada. Evidence demonstrates that the Alpha and Delta variants are at least 50% more transmissible. As well, the Gamma, Beta, and Delta variants each have certain mutations, which may have an impact on vaccine effectiveness, although the evidence is still limited. Nevertheless, we know that vaccination, in combination with public health and individual measures, are working to reduce spread of COVID-19.

As vaccine eligibility expands, Canadians are urged to get vaccinated and support others to get vaccinated as vaccines become available to them. However, regardless of our vaccination status, it is important to remain vigilant, continue following local public health advice, and consistently maintain individual practices that keep us and our families safer, even as we're beginning to see the positive impacts of COVID-19 vaccines: stay home/self-isolate if you have any symptoms, think about the risks and reduce non-essential activities and outings to a minimum, avoid all non-essential travel, and maintain individual protective practices of physical distancing, hand, cough and surface hygiene and wearing a well-fitted and properly worn face mask as appropriate (including in shared spaces, indoors or outdoors, with people from outside of your immediate household).

For more information regarding the risks and benefits of vaccination, I encourage Canadians to reach out to your local public health authorities, healthcare provider, or other trusted and credible sources, such as Canada.ca and Immunize.ca. Working together, Health Canada, the Public Health Agency of Canada, the National Advisory Committee on Immunization, Canada's Chief Medical Officers of Health and other health professionals across the country are closely monitoring vaccine safety, effectiveness and optimal use to adapt approaches. As the science and situation evolves, we are committed to providing clear and evidence-informed guidance in order to keep everyone in Canada safe and healthy.

Canadians can also go the extra mile by sharing credible information on COVID-19 risks and prevention practices and measures to reduce COVID-19 in communities. Read my backgrounder to access more COVID-19 Information and Resources on ways to reduce the risks and protect yourself and others, including information on COVID-19 vaccination.

SOURCE Public Health Agency of Canada