Assessing COVID-19 risks in Edmonton

Alberta entered Stage 3 of its reopening plan on July 1, 2021. This phase means that most restrictions from the COVID-19 pandemic are dropped across the province, including the provincial mask mandate and restrictions on indoor and outdoor gatherings. Come August 16, many additional changes will be coming to lower COVID-19 restrictions.

Restrictions were also relaxed here on a local level. Edmonton city council has chosen to drop its mandatory mask bylaw in line with the provincial reopening plan. This means that, going forward, masks will only be required in certain circumstances in the city of Edmonton.

This stage of reopening is based on provincial vaccination numbers. Currently, Alberta has administered more than 5 million doses of the COVID-19 vaccine. More than half of eligible Albertans are fully vaccinated, and more than 70% of eligible Albertans are partially vaccinated. You are considered fully vaccinated two weeks after your final vaccine dose of an approved shot.

Despite our vaccination targets and decline in COVID-19 cases, the virus hasn’t vanished. Many cases are still active today, and new cases are discovered each day. Variants of concern, which are different strains of the original novel coronavirus, may become the dominant strains of the virus in Canada and elsewhere. This warrants a closer look at some of the risks that come with our reopening.

Vaccination rates

Fully vaccinating the population is our fastest way of achieving herd immunity. Herd immunity is when a large enough portion of the population is immune to a disease, making the spread of the disease more unlikely and protecting the whole population. It’s estimated that the threshold for herd immunity from COVID-19 is between 70 and 90% of the population. However, this raises some questions about how effective vaccines are, and what that 70% marker means in reality.

The effectiveness of vaccines is a measurement of immunity from symptomatic illness in those who have received the vaccine. It’s found through trials the vaccines are put through before they’re made available to the public. According to The Lancet, a 95% effectiveness rate means that, with a cumulated COVID-19 attack rate over a period of 3 months of about 1% without a vaccine, we would expect roughly 0.05% of vaccinated people would get COVID-19.

So, if 100,000 people are vaccinated and that protects 95% of them, that would leave 5,000 individuals with symptomatic disease over three months. This means that instead of 1,000 COVID-19 cases in a population of 100,000 without the vaccine, we would expect 50 cases (99.95% of the population is disease-free, at least for 3 months.)

Despite all of this, our evolving vaccine numbers tell a different story. Our push for 70% of the population being vaccinated only measures within the rate of the eligible population (aged 12+) which only accounts for 60% of the total population. Edmonton and Calgary lead the way in total vaccines administered, but many communities outside of these centers have much lower vaccine coverage. Much of the population is not fully vaccinated, and many Albertans are not vaccinated at all. 

But does a single vaccine dose provide enough protection? The data shows it can; a U.S. study found that one dose of Pfizer of Moderna's vaccines were at least 80% effective against novel coronavirus infections after 14 days. For the AstraZeneca-Oxford shot, it’s estimated to provide at least 70% protection from the virus for 90 days after the first dose. So while one dose is better than none, there are other factors to the virus that need consideration.

Variants of concern

It’s worth noting that the effectiveness of each vaccine was tested with the original strain of the novel coronavirus in mind. Variants of this strain present a different set of conditions for vaccine efficacy. Each variant of the novel coronavirus has been found in Edmonton, inclu Brazilian variant (Gamma variant), and the B.1.617 India variant (ding the B.1.1.7 U.K. variant (Alpha variant), the B.1.351 South African variant (Beta variant), the P.1Delta variant.)

A key point is that the efficacy of each shot is reduced depending on the variant. Below outlines the effectiveness of each of the vaccines at preventing symptomatic illness. The C.37 Peru variant (Lambda variant) has also been identified in Alberta, and is classified as a variant of interest. At time of writing, you can keep up to date with the COIVID-19 variants by checking the data on the province’s website.

Single dose of Pfizer/Moderna

Alpha variant: 55-70%

Beta variant: 61%

Gamma variant: 73%

Delta variant: 33.5%

Fully vaccinated with Pfizer/Moderna

Alpha variant: 85-90%

Beta variant: 96%

Gamma variant: 91%

Delta variant: 88%

Single dose of AstraZeneca

Alpha variant: 55-70%

Beta variant: 33.5%

Gamma variant: N/A

Delta variant: 33%

Fully vaccinated with AstraZeneca

Alpha variant: 65-90%

Beta variant: 48%

Gamma variant: N/A

Delta variant: 60%

More data is needed before we can understand vaccine efficacy against the Lambda variant. It’s important to remember that these numbers measure the protection against symptomatic disease. It’s possible for breakthrough infections to occur, but the vaccines still provide a great deal of protection against serious illness, hospitalization, and death. This makes vaccination a highly effective tool for protecting yourself against serious outcomes even if you get COVID-19.

While each vaccine is highly effective against severe outcomes, variants of concern present a threat to collective immunity, especially for those who cannot get vaccinated. There are many unanswered questions about the Delta variant, especially while most of the province is only partially vaccinated. In the meantime, those of us who cannot get vaccinated or are immunocompromised can try to manage the risks ahead.

Personal protection post-restrictions

Each of us may feel a varying degree of comfort with the pulling back of broad pandemic restrictions. Each of us may also feel a certain degree of personal risk related to catching COVID-19. Despite the lack of widespread pandemic restrictions, there are still a few ways to help mitigate the risk of catching the novel coronavirus.

Currently, the best way to protect yourself is to get fully vaccinated. The CDC guidelines for the fully vaccinated suggest that the fully vaccinated can return to many pre-pandemic activities, while abiding restrictions in place by a regional government and in healthcare settings. To best protect yourself from the Delta variant, wearing a mask in public indoor settings can help in areas of high transmission risk.

Masks are also recommended for folks at risk, including:

  • folks with an increased risk of severe disease or outcomes,

  • folks with a weakened immune system, because of age or an underlying medical condition,  

  • those of us who are not fully vaccinated, and

  • folks with someone in their household with a weakened immune system or an increased risk for severe disease, or is unvaccinated

Health Canada also offers some guidelines around masking for additional protection. These measures offer different recommendations in different settings to address the likelihood of getting the virus. Regardless of vaccination status, some situations may call for wearing a mask and maintaining distance if you are at risk for severe disease or outcomes. 

For some of us, this reopening period may produce a great sense of anxiety. Reduced restrictions can make others feel vulnerable, like those who cannot get vaccinated, are immunocompromised, or still waiting for their second dose. It may also be stressful to return to some sense of “normal” after having followed public health restrictions for 15 months.

If you are fully vaccinated and not at risk for severe outcomes, try lending a hand to those around you who may feel vulnerable right now. If you are struggling with anxiety around relaxed restrictions, please reach out to your friends, relations, or community members. Try to access some of the local mental supports available.

  • Health Link – 811

  • Mental Health Help Line – (available 24/7) Call 1-877-303-2642

  • Canadian Mental Health Association – Edmonton (available 24/7) Distress line: (780) 482-4357

  • CMHA (Edmonton) – Advocacy: Call (780) 414-6300 or email main@cmha-edmonton.ab.ca

Over the coming weeks and months, we’ll begin to carve out a better picture of how people can stay safe post-pandemic restrictions. COVID-19 may be here to stay, and learning how we can better manage it will help each of us return to a more normal life.