Delta Variant

As vaccinations increase in Canada and Covid-19 cases continue to decline, there is a general sense of optimism that the pandemic is almost over. However, reports from the UK on the rapid spread of the Delta variant, first discovered in India, provide an ominous forecast.

In the past, trajectories of the coronavirus in Europe and the UK have not been followed very seriously in North America. Our “experts” and political leaders have adopted a “wait and see” approach. This happened with the original coronavirus outbreak in March 2020, the second wave that started in September and the third wave (due to the Alpha, or UK variant) in March 2021. The result was that in most cases public health action was delayed and not optimal.

In a crisis, this is not the right thing to do. The right thing to do is to be prepared and plan for the worst. 

Here is what has been reported in the UK (June 11).
– 90% of new Covid cases are now the Delta variant.
– Cases are doubling about every 10 days.
– The Delta variant is 60% more transmissible than the Alpha variant, which makes it 140% more transmissible than the original Covid-19.
– The first vaccination is only about 30% effective; but the second shot provides 80% effectiveness.
– There are some cases of fully vaccinated people getting Covid, and dying.
https://www.theguardian.com/world/2021/jun/11/delta-variant-is-linked-to-90-of-covid-cases-in-uk

Modelling in the UK shows that a third wave of infections could rival Britain’s second wave from the Alpha variant. To counteract this, Prime Minister Boris Johnson delayed the final stage of easing lockdown restrictions for 4 weeks until 19 July.
https://www.bbc.com/news/uk-57476776

What’s the risk in Canada?

The last projection in the May 12 blog predicted “restrictions being removed in July. There is no surge and cases continue to decline to a negligible number”. 

But this did not include the Delta variant. It has now been added to the model using the characteristics of the Delta variant summarized in the following report, assuming 16% of all Covid cases are the Delta variant on June 18, rising to 90% in the first week of August.

In addition, the relaxation of controls was applied, using the guidelines that most provinces are following. These are the steps in the Ontario reopening plan, with at least 21 days between steps.

Step 1: 60% of adults vaccinated with one dose.
Step 2: 70% of adults vaccinated with one dose and 20% vaccinated with two doses.
Step 3: 70 to 80% of adults vaccinated with one dose and 25% vaccinated with two doses.
https://www.ontario.ca/page/reopening-ontario

Ontario, B.C. and Alberta entered Step 1 in the second week of June.
The model projects proceeding with
– Step 2 in the first week of July.
– Step 3 in the last week of July.
– Fully reopen first week of September.

Here is the picture with these assumptions.

So cases continue a rapid decrease into July but start to rise as controls are relaxed and the Delta variant spreads.

It remains to be seen which provinces delay advancing to the next reopening step when cases increase or just “wait and see”, allowing the Delta variant to spread and hoping that the increase in full vaccinations will reduce the spread in September.

What’s the risk in the U.S.?

The fully vaccinated rate is 44% In the U.S. compared to 14% in Canada. This means there is more resistance to the spread of the Delta variant. But all states except 4 have reopened completely which allows the coronavirus to spread more easily.
https://www.nytimes.com/interactive/2020/us/states-reopen-map-coronavirus.html

The U.S. could see a fourth wave similar to the one in Canada in the summer or autumn. There are also many regions in the U.S. that have very low vaccination rates. There will likely be several outbreaks in these parts of the country as the Delta variant spreads. 

How to keep up with the Delta variant?

You can easily follow the Covid-19 trend without waiting for a news report. Just watch this chart “New Covid-19 Cases per Million People” which is updated daily.
https://tinyurl.com/76t5h6vn

It clearly shows the Delta variant in the UK taking off on May 25. If the curve for Canada or the U.S. starts a steep rise like this, you know they are headed for trouble.