D.he news with which British Prime Minister Boris Johnson appeared in front of the press on Friday evening was not good: There are indications, he said, that the new virus variant B.1.1.7, which has now been detected in 20 countries around the world, is deadlier than the ones circulating so far.
The Nervtag expert group (The New and Emerging Respiratory Virus Threats Advisory Group) had evaluated a total of four different studies in which, among other things, the death rate of infected people was analyzed. In a summary of these studies, the scientists come to the conclusion that the variant increases mortality.
However, they emphasize, the increase in the death rate is not drastically higher than with the previous virus variants. However, they do not give the all-clear: some Covid 19 patients only die weeks after their infection. This can result in the death rate ultimately turning out to be higher.
The Nervtag consortium assumes that out of 1000 60-year-olds infected with B.1.1.7, 13 to 16 die. With the previously known variants, the rate was 10 out of 1000.
“The most worrying thing is,” said David Strain of the University of Exeter to the UK Science Media Center, “that the death rate in the clinics is the same, but the overall mortality is 30 percent higher.” Strain referred to one of the studies considered, presented by Sir Patrick John Thompson Vallance, Clinical Pharmacologist and Chief Scientific Adviser to the UK Government.
To illustrate this, if one were to assume that the mortality rate in the hospital is 10 percent for both variants, 130 people would now have to go to the clinic who were infected with the new variant. So far there have only been 100. That could explain why hospitals currently have 79 percent more patients than they did during the first wave peak.
Strain also emphasized that the Nervtag consortium has only been able to take into account eight percent of all Covid 19 deaths in the evaluation. “We need a lot more data before we can draw too many conclusions.”
Data are still very preliminary
The virologist Julian Tang from the University of Leicester noted that there are many different influencing factors that determine the course of a Covid-19 infection. Ethnic affiliation, age, gender, previous illnesses and also the workload of the health care system belonged to this, for example.
The data on which Patrick Vallance and Nervtag were based included relatively few cases of B.1.1.7 variants. There was no precise breakdown of the background of the various patients.
“But we know that the death rate for patients with certain pre-existing conditions is generally increased in winter. The mortality of such patients is generally higher in winter – regardless of a virus. ”Patients with heart disease often experience a sudden deterioration in their health in the winter months. Winter increases the stress on the heart and the risk of heart attacks increases. Against this background, the difference from 10 to 13 more deaths per 1000 is not particularly high due to the new variant.
Nevertheless, Tang emphasizes: “Apart from that, the message remains the same: We must continue to reduce our social contacts and try to stay at home to reduce the spread of the virus – until most of the risk patients are vaccinated.”
What the virus does in the cells
In view of the Nervtag presentation, the microbiologist Simon Clarke from the University of Reading gives an overview of what can be safely said about the molecular properties of the new virus variant.
Initial studies indicated that the mutations did not negatively affect the virus’ antibody response, which the body uses to prevent it from entering human cells, Clarke said. “We don’t yet know whether the mutations change the spike protein or other parts of the coronavirus in such a way that antibodies can make it less visible to the white blood cells.” If this were the case, the body could not build up an immune memory as well and that The risk of re-infection with the virus would increase. It is also not yet clear whether the T cells, which can detect and kill cells infected by the virus, respond just as well to the new variants as to previous ones.
“But we know that the new variant can bind better to our cells. This could trigger a more severe overreaction of the immune system, which in turn can lead to serious illness and death. “
Ian Jones, Professor of Virology at the University of Reading adds: “The data from Nervtag are not comprehensive and the shots taken from them are therefore only preliminary.” But an increased case mortality is quite conceivable. But it is not as dramatic as it sounds. “Whether the death rate is one percent or 1.3 percent doesn’t change the fact that the virus is a very dangerous virus for a small number of people that you have to avoid.” You can do that with strict adherence to the lockdown regulations and by being prepared for a quick vaccination. “Since the vaccine works just as well against the old as the new variant, the number of infections should decrease as soon as the vaccination progresses.”
Lawrence Young, Professor of Molecular Oncology at Warwick Medical School also emphasizes that there is so far no evidence that the vaccines against B.1.1.7 are ineffective. “Laboratory studies have shown that antibodies from test subjects who have been vaccinated with the Pfizer / Biontech vaccine can prevent the new UK variant B.1.1.7 from entering the cells.”
Artificially produced viruses with the changes in the spike protein that are typical for B.1.17 would also be blocked by antibodies from those recovered from the original variant. “These studies instill confidence that the vaccinations also protect against illness with the new variant.”