Covid-19 Vaccines – How Successful are they in Bringing Cases and Deaths Down (March 2021 Data)

With Covid-19 vaccines now becoming a reality, the question of their impact at the national level naturally comes up. Different countries are scrambling to get hold of vaccines, with the expectation that this will allow them to open up their economies and get back to normal (and reduce human suffering).

A previous blog looked at the effect of vaccines on cases and deaths during the Jan-Feb 2021 period. This is a second look at the relevant data, focusing on what happened during March 2021.

Here’s the graph, with a linear trend added:

Here’s the same graph, with a logarithmic trend added.

I should note a few things about the countries selected for the graphs:

· There is a lot of volatility in the numbers for countries with low populations, so this graph only includes those with 10 million or more people.

· Any countries that have not yet had a vaccine rollout are excluded, as the effect of vaccines on Covid case and death rates is obviously not relevant for them.

· Any countries that had 0 deaths in the late 2020 data are excluded, as the index number is not defined in this case (divide by 0)

· These graphs are limited to countries in Asia, Europe and North America that fit the above criteria and for which there is publicly available data. These areas have relatively reliable data and are also north of the equator, so the seasonal effects of the virus will be similar for them.

As you can see, there does seem to be an early vaccine effect showing up, though the evidence is still rather weak. In both cases, the effectiveness of the vaccine is somewhat stronger with the death counts than the case counts. The early (Jan-Feb) data showed the opposite effect, which I expected to change, and it did. Since deaths are very contingent on age (older people are more likely to die) and vaccine roll-outs were generally prioritized by age, it is a reasonable assumption that that the effect of vaccines would show up at an earlier stage than the effect on case counts.

In this data, the linear trend indicates that about 9% of the variation in the change in cases and deaths between countries (the R-square) can be attributed to the level of vaccination rollout among those counties, while about 11% of the variation in deaths can be attributed to vaccine roll-outs. If a logarithmic trend is used, the R-square values are 4% for cases and 14% for deaths. So, there is a case to be made for each of the functional forms. As time goes on, and vaccination roll-outs progress, these trends should become more obvious.

The graph data for the U.K. and the U.S. are fairly striking. These countries have had the largest vaccine roll-outs and the effects on cases and deaths is obvious, particularly for the U.K.. Some other countries have also had significant reductions in deaths (e.g. Canada, Belgium) with much lower vaccination roll-outs. Conversely, some countries have experienced higher deaths or cases, even with some vaccine rollout having occurred (e.g. Czech Republic, Dominican Republic). Overall, though, the hoped-for effect (i.e. a reduction) of vaccination rates on deaths and cases is evident.

There are a number of points about these graphs to be aware of, which I noted in the Jan-Feb analysis and still are valid:

· A lot of the cases and deaths seen in the latter period were already “locked in” by the time the vaccines were being rolled out (i.e. they were infected in the first period, but the symptoms didn’t show up until the second period). So, the effect of vaccinations at the population level would be obscured by that.

· That’s especially true for deaths, since the time lag between being infected and dying is quite long, when compared to the relatively short time intervals being analyzed here. So, deaths in the second period could be the result of infections quite early in the first period.

· Similarly, there is a lag time between being vaccinated and the body’s immune system kicking in stongly, so that creates another obscuring factor. For example, a person could be vaccinated on “Day t”, but be infected on “Day t+2”, before the immune system has had time to ramp up. So, though there was a vaccination, it didn’t have time to stop an infection.

· The second period corresponded with a new wave of infections in many countries, due to some new, more contagious variants of the virus evolving. That adds a lot of randomness to the data, as these outbreaks occur at different times in different countries.

· Different countries have used different vaccines, which have somewhat different efficiencies.

· Different countries have had various degrees of lock-downs over these periods. That also obscures the effect of vaccination roll-outs (e.g. a vaccination rollout could occur in one country at the start of a a new outbreak, so even if the vaccinations are working, cases and deaths could still increase. Conversely, a country with no or little vaccinations could just happen to be coming out of an outbreak from the first period to the second, so they would be doing better even without vaccines. Both of these possibilities make the effect of the vaccinations harder to see.

It will be interesting to see how the effect of vaccinations continue to reveal themselves over time. I expect that the death rates from Covid-19 will go down dramatically after the most vulnerable groups are vaccinated first (older and sicker people). Cases may continue to be high until younger age groups can get the vaccine, and that will take quite a while.

So, the social and economic pressures to re-open may become quite intense at that rate, even though many will want to maintain lock-downs until cases fall dramatically. I expect that there will be a lot of heated discussion of this within a couple of months, in many countries. For example, the concern about fatalities might shift from absolute numbers of deaths to potential years of life lost, as the proportion of deaths shifts from older ages to younger ages. Conversely, the negative social effects on younger groups may be emphasized more, as the older groups vaccination rates approach 100%, which would argue for an end to hard lock-downs, as the absolute number of deaths will be low.

Sources:

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/2021/03/covid-19-vaccines-how-successfully-are.html

https://dodecahedronbooks.blogspot.com/2020/12/covid-19-vaccines-comparison-of.html

https://dodecahedronbooks.blogspot.com/2020/09/covid-19-continues-to-travel-around.html

https://dodecahedronbooks.blogspot.com/2020/07/has-covid-19-become-less-deadly.html

https://dodecahedronbooks.blogspot.com/2020/07/july-2020-update-covid-19-death-rates.html

https://dodecahedronbooks.blogspot.com/2020/05/covid-19-death-rates-correlate-highly.html

https://dodecahedronbooks.blogspot.com/2020/06/covid-19-impact-on-employment-no-impact.html

https://dodecahedronbooks.blogspot.com/2020/04/is-there-model-that-can-predict-when-to.html

https://dodecahedronbooks.blogspot.com/2020/03/estimating-fatality-rate-of-coronavirus.html

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And, here’s a more pleasant travel story than anticipating the worldwide journey of a virus.

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 Kettle Valley Rail Trail is one of the longest and most scenic biking and hiking trails in Canada. It covers a good stretch of the south-central interior of British Columbia, about 600 kilometers of scenic countryside. British Columbia is one of the most beautiful areas of Canada, which is itself a beautiful country, ideal for those who appreciate natural splendour and achievable adventure in the great outdoors.

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

Spring is on us now, and that brings on thoughts of ROAD TRIP. Sure, it is still a bit early, but you can still start making plans for your next road trip with help of “On the Road with Bronco Billy”. Sit back and go on a ten day trucking trip in a big rig, through western North America, from Alberta to Texas, and back again. Explore the countryside, learn some trucking lingo, and observe the shifting cultural norms across this great continent. Then, come spring, try it out for yourself.

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