On the internet, the claim is spreading that the Delta variant is more harmless than other corona variants.
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On the internet, the claim is spreading that the Delta variant is more harmless than other corona variants.

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Delta variant not more dangerous for vaccinated people

Delta variant not more dangerous for vaccinated people

On the internet, the claim is spreading that the Delta variant is more harmless than other corona variants, but more dangerous for vaccinated than for unvaccinated people. Figures from the English health authority PHE serve as proof. A #Faktenfuchs.

In England, the authorities have a very good overview of the spread of the different variants of the coronavirus SARS-CoV-2. If a Covid test is positive there, the genetic material of the viruses in the sample is sequenced much more frequently than in most other European countries. With the help of this sequencing, different variants of the virus can be detected.

Public Health England (PHE) regularly publishes up-to-date data on new and worrying virus variants circulating in the country. Scientists abroad also use this data to track the spread of individual variants.

The PHE figures, however, are also used by pandemic downplayers and deniers. Facts from official sources are supposed to seemingly support their claims and discredit the measures against the pandemic. In doing so, they use well-known methods: they cherry-pick figures, but conceal the necessary context that makes it possible to classify the data correctly.

  • You can find all multilingual #Faktenfuchs articles here.

False claim 1: Delta variant is more harmless than previous variants

"The delta variant is the most harmless one identified so far. It is more harmless than any flu", can be read, for example, in an article on Boris Reitschuster's website.

Peter F. Mayer, the author of the article, wants to substantiate this claim with figures from PHE (specifically from SARS-CoV-2 variants of concern and variants under investigation in England: technical briefing, issues 16 to 18). In these reports, the numbers of Covid-19 cases detected as well as the virus variants detected are listed in tabular form. In addition, the number of infected persons who died and the so-called Case Fatality Rate (CFR) for the individual virus variants are shown.

The CFR indicates the percentage of people who have died from a disease, in this case Covid-19. People in whom an infection with the coronavirus is asymptomatic and often goes unnoticed are not counted here among those who have fallen ill.

At first glance, the PHE data seem to confirm the claim that the Delta variant is less lethal than other coronavirus variants. In issue 18 of the PHE report of July 9, 2021, the column for Case Fatality Rate actually states Alpha 1.9 per cent, Beta 1.4 per cent and Delta 0.2 per cent.

Data of the variants not comparable with each other, according to PHE

In the article on Boris Reitschuster's website, however, a crucial piece of information is missing. PHE points this out in the text appearing directly before the table and also in a footnote below it: "Note case fatality rates are not comparable across variants." In other words: the Case Fatality Rates for the variants cannot be compared with each other. The reason is as follows: the variants were differently widespread at different times.

The Delta variant did not spread in the UK until a large part of the population (and especially the risk groups) had already been vaccinated and thus protected against severe courses of the disease. Covid-19 treatment options also improved during the course of the pandemic. Moreover, during the winter of 2020/21, when the Alpha variant was still dominant, the British healthcare system was so heavily burdened that not all Covid-19 patients could be treated to the same extent as it is currently the case.

Consequently, the lower Case Fatality Rate for the Delta variant compared to other variants does not prove that the Delta variant is less dangerous - but in fact shows the success of vaccinations in the UK.

False claim 2: Double-vaccinated people die more often than unvaccinated people from the Delta variant

The 18th edition of the PHE report contains further tables. One of them shows how many people infected with the Delta variant had to be treated as emergencies and/or died between the beginning of February and the end of June.

The report also indicates whether the persons concerned were vaccinated once, twice, or not at all. A total of 123,620 Delta cases were detected during this period. 10,834 of those infected had already received two doses of vaccine, while 71,932 were unvaccinated. Of the double-vaccinated, 118 had died, compared to 92 of the unvaccinated. Anti-vaccinationists use these figures to claim that double-vaccinated people die many times more often from the Delta variant than unvaccinated people.

This is also a misinterpretation of the figures. The apparently high number of deaths among the vaccinated can be explained by statistics and the following two facts. Firstly, the vaccines do not protect completely. Secondly, the number of fully vaccinated people is constantly increasing.

The Covid-19 vaccines prevent 66 to 95 percent of disease, as studies for their approval showed. However, these studies mainly involved young and healthy subjects. People with a weakened immune system and the elderly were underrepresented. But these people have an increased risk of contracting Covid-19 severely, which is why they were vaccinated first.

For them, however, the vaccines apparently do not work as well as for young and healthy people. This means that despite being fully vaccinated, people will continue to be infected with the coronavirus, fall ill with Covid-19 or even die. This is especially true for people from the risk groups. Because those who are seriously ill and/or old are more at risk than people with an intact immune system, even if they have been fully vaccinated.

On the other hand, more and more people are fully vaccinated and their share in the population is rising. Therefore, the number of vaccinated people who become infected despite vaccination and subsequently fall ill or die is also increasing. However, the unvaccinated currently make up the majority of those infected, because they are more likely to become infected (according to PHE, unvaccinated people under 65 are infected three times as often as vaccinated people in the same age group). But only very few unvaccinated people die from Covid-19, because in the UK, too, it is largely younger people who are not (yet) vaccinated.

Consequently: The more vaccinated people there are, the larger their share in the corona deaths is. And vice versa: if the number of unvaccinated people decreases, their share in the Covid-19 deaths decreases as well. Regardless of this, however, the overall number of corona deaths shrinks over time during a given period, as vaccinations in the UK, as in other countries, have an effect.

How easy it is to draw false conclusions from the percentages of a statistic of corona deaths is shown by a vivid comparison by Christoph Rothe, Professor of Statistics at the University of Mannheim, on Twitter. He also transfers it to the number of corona deaths: In the UK, almost all Delta deaths are in the age group over 50. This group has a vaccination rate of around 93 percent. The roughly seven percent of unvaccinated people over 50 therefore account for almost 60 percent of all deaths.

Conclusion

The PHE data cited by corona downplayers are correct but are used without context. The claim that the Delta variant is less dangerous but more deadly for vaccinated people cannot be concluded from the data.

Firstly, figures from different phases of the pandemic cannot be compared. The more people are vaccinated against Covid-19, the less dangerous the coronavirus is for the population as a whole. Which variant is currently circulating is of secondary importance.

Secondly, the vaccines are not one hundred percent effective. If there are many vaccinated people, there are also many who get infected, fall ill or die despite vaccination. The share of the unvaccinated in the corona deaths only seems to decrease. A direct comparison shows that the vaccinated are significantly better protected against a severe or fatal course of Covid-19 than the unvaccinated.

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