Omicron is here. The most crucial action we can take to prepare is to get our booster vaccine

This Opinion piece was written by Dr. Nazeem Muhajarine who is it an an epidemiologist and professor of community health and epidemiology at the University of Saskatchewan's college of medicine. He is also a member of the Coronavirus Variants Rapid Response Network (CoVaRR-Net), a national research network investigating and disseminating research on variants of SARS-CoV-2 virus. 

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The Omicron variant could hardly have arrived at a worse time.

We are all tired of the pandemic. We have seen four waves rise and subside and now, with our case numbers finally having fallen in the Prairies, we are breathing a sigh of relief.

Most of us have two vaccine doses and children have begun to get vaccinated too, so we feel protected. And now, just as we are making plans to get together with our friends and families over the holidays, what may be the most threatening variant yet is knocking on our door.

Two weeks ago, experts were guardedly saying that Omicron looked ominous with its 50-plus mutations, but little was known then about this new variant. Scientists around the world have been scrambling to study Omicron's characteristics and it is becoming increasingly clear what we need to do, and how quickly we need to do it.

One thing we know for sure is that Omicron spreads and infects people much more effectively than any other variant, including the currently circulating Delta.

The situation in Ontario gives us a heads-up of what we can expect in Saskatchewan. In just two weeks since the first two Omicron cases were detected in that province, case numbers have skyrocketed, and Omicron is on the verge of taking over from Delta as the most common variant.

Remember back in March 2020, when we were all doing our best to "flatten the curve"? The path that Omicron takes is not so much a curve as a line that goes straight up. While each person infected with the Delta variant passes the virus on to 1.3 people on average, with Omicron, that number is more than three times higher.

A second concern is whether Omicron can get around the immunity created by vaccination or a previous COVID infection. We will have a better understanding of this in a few weeks, but early data shows that Omicron can break through the first line of our immune defenses, our antibodies (whether they were produced as a result of having COVID or being vaccinated).

Fortunately, our immune system also includes other defenses, in the form of T-cells and B-cells. These seem to hold against Omicron.

The third critical question is whether infection with Omicron produces less severe illness than previous strains.

While we are all hoping this is the case, it is too early to know for sure. The Canadian population is very different from that of South Africa, which is where we have been getting data about Omicron severity. We have more people vaccinated but considerably fewer people with immunity from previous infections, and our population is much older on average.

Even if Omicron results in less serious illness overall — and we do not yet know if it will — if the total number of infections increases dramatically, we could still see a lot of hospitalizations that will once again strain our exhausted health care system.