That’s why omikron rounds off our defense – Sydsvenskan

Omikron has in a short time become the dominant virus variant – and it is no coincidence.

– The variant is something out of the ordinary, says vaccine researcher Ali Harandi.

The coronavirus variant omikron has several properties that make it more contagious than previous variants. The picture is an illustration.

During the latter part of November last year, South African researchers alerted about the then newly discovered coronavirus variant B.1.1.529. On November 26, the World Health Organization, WHO, described it as a “virus variant of special significance” and the variant was named omikron.

Now with the results in hand, just over a month and a half later, it can be stated that omikron has spread across the world with unprecedented speed.

Many mutations

The state of knowledge about omicrons is still uncertain, but research points to two properties that have enabled the rapid spread. On the one hand, omicron has an ability to bind more easily to cells and on the other hand, an ability to get past the protection built up by vaccines and previously reviewed covid-19. This makes omikron far more contagious than previous variants.

Advertisement

In a Chinese study, which has not yet undergone mandatory review, the researchers point out that omicron carries 30 mutations from previous variants, 10 of which concern the ability to bind to cell receptors – so-called affinity.

Advertisement

According to Ali Harandi, researcher in immunology at the University of Gothenburg, omikron is to be regarded as something out of the ordinary.

– If we look at other virus variants of special importance, they have not accumulated so many mutations. In the omicron, we see many mutations in a site that is critical to the virus’ ability to infect and bypass immunity from previous infection or vaccination.

Expected development

The fact that the virus is more contagious and to a greater extent attacks the upper respiratory tract facilitates the spread. At the same time – based on what is now known – people usually do not get as sick from omikron. Overall, it is beneficial for the virus – to be able to infect more people, but at the same time not kill their hosts.

– Purely evolutionary, this was expected. But considering how many mutations it is about and how fast it went, this was unexpected, Ali Harandi adds.

Ali Harandi leads a laboratory for vaccine research with about eight members at the University of Gothenburg.

Another Chinese study, which will be officially published at the end of January, claims that the protection provided by antibodies against previous variants is 85 percent weaker against omicrons.

Ali Harandi points out, however, that it is difficult to determine a percentage in terms of the degree of immunological protection and that the body’s ability to resist infections is very complex to comprehend.

Advertisement

Advertisement

– You have to put everything in context. Antibodies are only part of the immunity to viruses, he says because he manages that a certain antibody protection remains and that in addition to a number of other defense mechanisms in the body, there is also immunity from T cells.

– From what we have seen so far, T-cell immunity has not been significantly affected. Simply put, the virus cannot bypass T-cell immunity as dramatically as an antibody response.

Origin unknown

It is not clear how omikron originated, but the research focuses on three theories.

One: The virus may have circulated within a limited group of people and had the opportunity to mutate and then spread on a larger scale.

Two: The virus may have mutated in a person with a severely weakened immune system, such as a person with a largely untreated HIV infection.

– They can be ill with covid-19 for up to six months and that gives the virus room to mutate, says Ali Harandi.

Three: The virus may have spread from human to animal where it mutated and then spread again to humans.

– It has previously been said that the virus originates from bats, but there are a number of domestic mammals that can also become infected with coronavirus, says Ali Harandi.

Fact

Facts: T cells

T cells are part of the immune system and a type of white blood cell that specializes in recognizing virus-infected cells. Antibodies attack the virus itself, while the T cell kills the infected person and thus the number of viruses decreases.

T-cell immunity has been shown in studies to be able to supplement the protection from antibodies against covid-19. T-cell immunity could explain why family members of people who have been ill themselves do not develop any symptoms.

Källor: “Robust T Cell Immunity in Convalescent Individuals with Asymptomatic or Mild COVID-19”, “Immunity to COVID-19 is probably higher than tests have shown”

Leave a Comment