This winter, unprecedented numbers of people in Canada have been infected with the highly contagious Omicron variant. Though declining, daily new case counts – averaging over 10,000 daily – together with other indicators of COVID-19 disease activity, including test positivity, Rt (or effective reproduction number), and wastewater surveillance trends – indicate ongoing widespread activity across the country.
Presently, severe illness trends are elevated or still rising in many areas of the country. Up to February 2nd, an average of over 10,000 people with COVID-19 were being treated in hospitals each day, including over 1,100 in intensive care, and over 140 deaths were reported daily.
As we continue to take measures to mitigate the impact of COVID-19 and protect our heavily strained health system, experts are learning more every day about the effectiveness of COVID-19 vaccines. At the same time, we are moving ever closer to more and better treatments. These advancements will help lighten the load that so many of us have been carrying in the space between us and through the difficult sacrifices we’ve made.
Since the outset of COVID-19 vaccination programs, Canada’s National Advisory Committee on Immunization (or NACI) and health authorities across the country have continued to monitor vaccine safety and effectiveness data.
What the latest data show is that, while two doses of COVID-19 vaccines offer reasonably good protection against severe disease, receiving an mRNA booster dose offers superior protection, keeping more people out of hospital and preventing more deaths. In general, data show that protection against hospitalizations is over 90% with an mRNA booster dose, which is 15% to 40% higher effectiveness than with just two doses.
There are many benefits of being fully up-to-date with COVID-19 vaccines across all eligible age groups. Protection ranges from the smaller and shorter duration against infection, through a somewhat larger reduction in symptomatic illness, to strong protection against severe outcomes.
Given the very large number of Canadians with a confirmed or apparent infection during the Omicron surge in particular, it is also important to highlight that previously infected people benefit from starting or completing their COVID-19 vaccination. Hence, for the best possible protection against severe illness now and going forward, health authorities continue to strongly recommend up-to-date COVID-19 vaccination for all eligible people, including for those who have had a COVID-19 infection.
Today, NACI is releasing updated recommendations on suggested intervals for administration of booster doses for those who have been previously infected. Notably, NACI suggests that an mRNA booster be given at least 6 months after the previous dose or three months following infection, whichever is longer.
However, as no vaccine is one hundred percent effective, it is important for everyone to continue to use personal protective measures – such as wearing a good quality, snug-fitting mask, avoiding crowding, and improving ventilation in indoor spaces.
For the many hard-won advancements that would not have been possible without the collective efforts of countless Canadians, thank you.
Read my backgrounder to access COVID-19 Information and Resources, including information on vaccination and ways to reduce your risk of infection and spreading the virus to others.
Remarks from the Chief Public Health Officer on Feb 4, 2022
The COVID-19 pandemic continues to create stress and anxiety for many Canadians, particularly those who do not have ready access to their regular support networks. Through the Wellness Together Canada online portal, people of all ages across the country can access immediate, free and confidential mental health and substance use supports, 24 hours a day, seven days a week. PocketWell, a free companion app to the WTC online portal, provides another way to help Canadians access online mental health and substance use resources, and measure and track aspects of their mental well-being.