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At a press conference on Friday, Patrick Vallance, the British government’s chief scientific adviser, said that the variant of the coronavirus that was discovered in the country this fall is not only more contagious, but also more dangerous.
– We are now sure that (the “British” variant) spreads more easily than the previous variant. We think it’s 30 to 70 percent easier to transmit, though we still don’t understand why, Patrick Vallance said.
Furthermore, he said, there is also evidence that the new variant is more deadly than the old one. The evidence is not strong, but it is there, according to Vallance.
The “British” variant is estimated to be 30 to 40 percent more lethal than the previous one. In an attempt to explain what the increased risk means, he said that if 1,000 people aged 60 and over are infected, an estimated 10 people will die from the old variant, while the death toll will be 13-14 people with the new variant.
But what does the evidence look like and how much should we be afraid of the new variant?
There are no cases in the hospital
Patrick Vallance’s statement is based on a balanced evaluation of several different studies.
However, none of these studies base their data on hospital outcomes. That is, where the people who were treated for covid-19 and who became ill with the new variant were compared with those who became ill with the previous one. Instead, the studies are based on data collected from people who tested positive in society.
In mid-January, the London School of Hygiene and Tropical Medicine and Imperial College London, both in the UK, presented two separate studies. When the researchers linked data from people who tested positive with recorded deaths, they saw a 30% increased risk of dying from the new variant.
John Edmunds is a professor at the London School of Hygiene and Tropical Medicine and its Center for Mathematical Modeling, and according to him, the differences that he and his colleagues saw were statistically significant.
“Unfortunately, it appears that the new variant is more contagious and potentially more deadly,” he told a news conference earlier this week.
Higher mortality
The two research groups proceeded in slightly different ways, but both had paired people who had been infected with the new and old variant with each other, and checked other factors, such as age and hospital capacity in different regions.
Researchers from the University of Exeter and Public Health England, respectively, have also investigated the matter, separately, and these studies showed even higher mortality with the new variant.
Based on these four analyzes, the “New and Emerging Respiratory Virus Threat Advisory Group” (NERVTAG) concluded that there is a “realistic chance” that the new variant is associated with a higher mortality rate, compared to the previous.
Scare tactics?
However, it is worth noting that the data used in the analyzes only covers about eight percent of deaths that occurred during the current period, so the result may not be representative of the entire population, NERVTAG notes. In addition, there is no indication that the risk of hospital care increases due to the new variant, which is difficult to obtain, if it were at the same time 30 to 40 percent more dangerous.
In the wake of last Friday’s press conference with Prime Minister Boris Johnson, other researchers have criticized the government and its advisers for unnecessarily intimidating people, as scientific evidence that the new variant is actually more lethal that the former is extremely weak. the. For example, the term “realistic possibility” is used in scientific contexts about something that is only 50 percent certain. Quite uncertain, in other words, critics say.
Johan Nilsson / TT
Since the new coronavirus (sars-cov-2) was discovered in 2019, there have been several so-called mutations, that is, changes in the genome. These mutations have occurred almost everywhere in virus proteins, but mutations in the so-called spike protein are considered the most interesting. This is because it is this protein that the virus uses to bind and enter the host cell.
The “British” variant, which was discovered in September last year, has the name B.1.1.7 and consists of 14 mutations that are unique to this particular variant, two of which are considered particularly interesting. Uno (N501Y) is a mutation believed to affect the ability of the virus to bind to the host cell. The second is called del69-70 and means that a small area is missing in the gene encoding the spike protein at positions 69-70. Researchers believe this means that the virus becomes more contagious.
Källa: Centers for Disease Control and Prevention (CDC) i USA.
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