Alberta Covid19 Vaccines Effect on Cases and Deaths by Age – The Oldsters are Alright, the Kids not so Much
Since I live in Alberta, Canada, I am particularly interested in the Covid19 situation in that province. Nonetheless, there are a lot of Covid commonalities around the world, so I tend to think that understanding the dynamics of the pandemic and the ensuing vaccination roll-outs in one place can be of more general interest (i.e. what works in one place will generally work in others). There are some caveats to that, of course. The level of economic development of an area will affect the pandemic’s development, as will other factors such as governmental form, weather and latitude.
In this blog, I will look at how vaccinations have affected Covid-19 cases and deaths by age. In Alberta, like many jurisdictions, the vaccination campaigns were staggered by age, with older groups getting vaccinated first. The reason for that was simply that they were the most likely to die from the disease.
Note that the data is downloaded from the government's Covid site (url in sources at end of blog).
All Ages Total
The first graph shows numbers of cases (left y-axis) and deaths (right y-axis) over the course of the pandemic in Alberta, up until late May 2021. Counts are given on a weekly bases.
Three big facts jump out at you from the graph:
· It is clear that there have been three main waves: a smaller wave early in 2000 (Wave 1), then two large waves in late 2000 (Wave2) and spring on 2021 (Wave 3). Wave 3 was the largest, about 18% larger than Wave 2. The funny zig-zag in Wave 2 is almost certainly an artifact of reporting irregularities around the Christmas season of 2020.
· During Wave 3, in spring 2021, the cases and deaths have become uncoupled. The lines for cases and the lines for deaths no longer overlie each other, as the number of deaths didn’t change very much during that time, while the number of cases increased by roughly a factor of six.
· The general trend over the pandemic was for both cases and deaths to increase, but cases increased at a greater rate than deaths (i.e. the death rate from Covid went down). This is indicated by the differing slopes of the two regression lines.
80 and Up Year Olds
The next graph also shows cases and deaths over this period, but looks only at the age 80 and up group.
The two striking facts about this graph are:
· There really was no significant Wave 3 for these older patients, or at any rate it was very attenuated, reaching only about one-tenth the height of Wave 2. Deaths in Wave 3 were even more attenuated, reaching less than one-twentieth the height of Wave 2.
· Cases and deaths had a very high correlation during the pre-vaccination phase of the pandemic (i.e. people in this age group who died, died very soon after being diagnosed). During the second phase, the correlation was much lower, indicating that a lower proportion of older patients died of the disease during this time and that the week of death had become quite decoupled from the week of diagnosis (i.e those who died were surviving for longer, before succumbing to the disease).
· The two regression lines have fairly similar slopes, compared to the All Ages graph.
70-79 Year Olds
60-69 Year Olds
The graph for the 60-69 year olds continues these trends, with Wave 3 cases now about two-thirds the size Wave 3 cases. However, the deaths in Wave 3 were only about one-quarter as many as Wave 2. The correlation between cases and deaths has weakened somewhat during the first phase of the pandemic (pre-vaccinations), but strengthened a bit in the second phase. The slopes of the two trend lines diverge somewhat more than for the older groups.
50-59 Year Olds
The graph for the 50-59 year olds is quite a bit different. Wave 3 cases have now somewhat exceeded Wave 3 cases, by about 15%. However, the deaths in Wave 3 were only about one-half as many as Wave 2. The correlation between cases and deaths has weakened somewhat, indicating that these patients who die, survive longer than the older groups, before succumbing, at least during the pre-vaccination phase of the pandemic. The slopes of the two trend lines have also diverged somewhat, compared to the 80+ age group.
49 and Under Year Olds
Wave 3 now has a considerably higher case count than Wave 2 did, by about 25%. The peak in deaths is similar, though the number of deaths in this age range is very small, so any trends might just be noise in the data (the number of deaths is small enough, that the line for deaths now looks like a step function).
Comparison of Three Broad Age Ranges
If we collapse the age categories into just three groups and graph cases and deaths for these groups, the differences become very stark. The youngest age group (0 to 49) had by far the most cases, partly because that population grouping is quite large and partly because their vaccinatio rates were fairly low by this point in the vaccine rollout. Wave 3 was larger than Wave2 for this group, while for the middle age group (50 to 69) the two waves were about the same size. For the oldest group (70 and up) Wave 3 isn’t detectable on this scale.
These results are more obvious in the normalized graph, where the number of cases at any time is expressed sat the percentage of total cases for that group. That puts the data for all three groups on a similar scale. It is clear from that graph that the eldest group had a very subdued Wave 3, as far as cases are concerned.
In terms of deaths for the eldest group, Wave 2 predominates by a large factor. This group is showing very little, if any, presence of Wave 3 and Wave 1 is actually somewhat larger than Wave 3. There is also a small wave between Wave 1 and Wave 2.
For the middle age group, Wave 2 also predominates, though Wave 3 is also quite detectable. That small wave between Wave 1 and Wave 2 can also be seen.
For the youngest group, there really isn’t any detectable wave in deaths at any point. The most that can be said is that deaths in this group, small as they were, mostly came in the second half of the pandemic.
The normalized graph for deaths shows many of the same features. The most striking feature of this representation is probably the divergence between the eldest grouip and the next eldest group in Wave 3.
Summary
The key take-aways from this data are:
· The vaccinated eldest group (70+) were very effectively protected from Covid-19 during Wave 3 in Alberta, which peaked in cases around late April 2021, with about 70 cases per week as opposed to about 410 per week during the Wave 2 peak of December 2020. They were also very effectively protected from Covid-related deaths, with those numbers dropping to quite low levels of about 8 per week during the Wave 3 peak as opposed to about 95 per week during the Wave 2 peak.
· The partially vaccinated next eldest group (60-69) were not as well protected from Covid-19 during Wave 3 in Alberta, with about 2100 cases per week as opposed to about 2300 per week during the Wave 2 peak. However, protection from from Covid-related deaths was better, with those numbers dropping significantly compared to the earlier wave (about 17 per week during the Wave 3 peak as opposed to about 50 per week during the Wave 2 peak).
· The very lightly vaccinated younger group (0-49) were not protected at all from Covid-19 during Wave 3 in Alberta, with about 9000 cases per week as opposed to about 7000 per week during the Wave 2 peak. Protection from from Covid-related deaths was better, with those numbers dropping from about 3 per week during the Wave 3 peak to about 2 per week during the Wave 2 peak. In either case, though, Covid-related deaths were very low in this group.
So, in terms of deaths, which are the highest concern, vaccinations have basically taken care of the oldest group and natural resistance basically takes care of the youngest group. Based on the evidence, vaccinations will soon take care of the middle group. So, as far as deaths are concerned, the pandemic is nearing its end in Alberta.
As for cases, vaccinations have largely taken care of the oldest group. The youngest group is still susceptible to Covid, and probaly will remain so until vaccinations pick up substantially in this group, or herd immunity kicks in. As with deaths, the evidence indicates that vaccinations will soon take care of the middle group. So, as far as cases are concerned, the pandemic still has a ways to go in Alberta.
My conclusion is that the region is fast approaching what may be called “practical herd immunity” as deaths are now low and will go lower. In my opinion, we should be adjusting regulations accordingly. While it is true that a more dangerous variant could arise, a society can’t shut down forever over hypothetical concerns. Continued vigelance is needed, though, to be on the watch for any dangerous new variants.
Sources:
https://www.alberta.ca/stats/covid-19-alberta-statistics.htm
https://www.worldometers.info/coronavirus/#countries
https://github.com/owid/covid-19-data/tree/master/public/data/vaccinations
Some earlier Covid-19 blogs:
· https://dodecahedronbooks.blogspot.com/2021/05/covid19-vaccines-effect-on-case.html Covid19 Vaccines Effect on Case Fatality Rates – Suddenly, then Gradually
· https://dodecahedronbooks.blogspot.com/2021/04/excess-deaths-vs-covid-19-deaths.html Excess Deaths vs Covid-19 Deaths
· https://dodecahedronbooks.blogspot.com/2021/03/covid-19-vaccines-positive-results-from.html Covid-19 Vaccines, Positive Results from Alberta Canada
· https://dodecahedronbooks.blogspot.com/2021/03/covid-19-vaccines-how-successfully-are.html Covid-19 Vaccines (March 2021 Data) – How Successful are they in Bringing Cases and Deaths Down
· https://dodecahedronbooks.blogspot.com/2020/12/covid-19-vaccines-comparison-of.html Covid-19 Vaccines – Comparison of Effectiveness, with Confidence Intervals
· https://dodecahedronbooks.blogspot.com/2020/09/covid-19-continues-to-travel-around.html Covid-19 Continues to Travel Around the World but Becomes Less Deadly While Doing So
· https://dodecahedronbooks.blogspot.com/2020/07/has-covid-19-become-less-deadly.html Covid-19 – Is it Now a Casedemic?
· https://dodecahedronbooks.blogspot.com/2020/07/july-2020-update-covid-19-death-rates.html July 2020 Update: Covid-19 Death Rates Correlate Highly with a Country’s Level of Globalization
· https://dodecahedronbooks.blogspot.com/2020/05/covid-19-death-rates-correlate-highly.html Covid-19 Death Rates Correlate Highly with a Country’s Level of Globalization
· https://dodecahedronbooks.blogspot.com/2020/06/covid-19-impact-on-employment-no-impact.html Covid-19 Impact on Employment: No Impact, Work at Home, or Laid Off (A Statistical Analysis)
· https://dodecahedronbooks.blogspot.com/2020/04/is-there-model-that-can-predict-when-to.html Is there a model that can predict when to ease Covid-19 restrictions?
· https://dodecahedronbooks.blogspot.com/2020/03/estimating-fatality-rate-of-coronavirus.html Estimating the Fatality Rate of the Coronavirus, from Time Series Correlation Analysis (Update March 5, 2020)
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And, here’s a more pleasant travel story than
anticipating
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A Drive Across Newfoundland
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Newfoundland, Canada’s most easterly province, is a region that is both fascinating in its unique culture and amazing in its vistas of stark beauty. The weather is often wild, with coastal regions known for steep cliffs and crashing waves (though tranquil beaches exist too). The inland areas are primarily Precambrian shield, dominated by forests, rivers, rock formations, and abundant wildlife. The province also features some of the Earth’s most remarkable geology, notably The Tablelands, where the mantle rocks of the Earth’s interior have been exposed at the surface, permitting one to explore an almost alien landscape, an opportunity available on only a few scattered regions of the planet.
The city of St. John’s is one of Canada’s most unique urban
areas, with a population that maintains many old traditions and cultural
aspects of the British Isles. That’s true of the rest of the province, as well,
where the people are friendly and inclined to chat amiably with visitors. Plus,
they talk with amusing accents and party hard, so what’s not to like?
This account focusses on a two-week road trip in October 2007, from St. John’s
in the southeast, to L’Anse aux Meadows in the far northwest, the only known
Viking settlement in North America. It also features a day hike visit to The
Tablelands, a remarkable and majestic geological feature. Even those who don’t
normally consider themselves very interested in geology will find themselves
awe-struck by these other-worldly landscapes.
A Ride on the Kettle Valley Rail Trail: A Biking Journal Kindle Edition
by Dale Olausen(Author), Helena Puumala(Editor)
The trail passes through a great variety of geographical and geological regions, from mountains to valleys, along scenic lakes and rivers, to dry near-desert condition grasslands. It often features towering canyons, spanned by a combination of high trestle bridges and long tunnels, as it passes through wild, unpopulated country. At other times, it remains quite low, in populated valleys, alongside spectacular water features such as beautiful Lake Okanagan, an area that is home to hundreds of vineyards, as well as other civilized comforts.
The trail is a nice test of one’s physical fitness, as well as one’s wits and adaptability, as much of it does travel through true wilderness. The views are spectacular, the wildlife is plentiful and the people are friendly. What more could one ask for?
What follows is a journal of two summers of adventure, biking most of the trail in the late 1990s. It is about 33,000 words in length (2 to 3 hours reading), and contains numerous photographs of the trail. There are also sections containing a brief history of the trail, geology, flora and fauna, and associated information.
After reading this account, you should have a good sense of whether the trail is right for you. If you do decide to ride the trail, it will be an experience you will never forget.
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On the Road with Bronco Billy
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