How will the effectiveness of rapid tests for coronavirus antigens change if the omicron comes to Russia after the “delta”? The effectiveness of most test systems based on RT-PCR will not change, experts say.
The variant of the coronavirus, which the WHO has designated as “omicron”, is alarming due to the unprecedented number of mutations. Many of these mutations are already known to be capable of deceiving the human immune defense mechanism. And this increases the rate of spread of “omicron” in the body and can lead to more severe consequences of the disease.
One of the decisive factors in countering the virus is the timely detection of the infection. However, the testing system does not have to be rebuilt: the existing kits effectively cope with this task. This is what experts around the world say.
Russian and foreign manufacturers of express tests, for example, report that the systems they have developed detect omicron just as successfully as other strains, and they see no reason to doubt the results.
For example, according to Harvard epidemiologist Michael Mean, quoted by the Boston Herald, the analytical data show that rapid tests detect the omicron strain as effectively as delta.
The reliability of rapid tests is also confirmed by the US administration’s plans to distribute up to 500 million kits to ordinary Americans in January through special websites, Business Insider reports.
As recently as Saturday, Russian Health Minister Mikhail Murashko, during a visit to the Rostov Region, noted the ability of all available COVID tests to diagnose omicron.
“We see that all the tests that have been created and are on the market today are working to diagnose a new coronavirus infection, including those caused by the omicron strain,” he told reporters.
Medical experts explain in scientific language that antigen tests usually use antibodies to the coronavirus nucleocapsid protein. And it is not surprising that antibodies recognize the omicron nucleocapsid.
The developers preliminarily study the fragments with which hybridization occurs; they already have a sufficient amount of genomic data at their disposal. They show that not many changes occur outside of the S-protein gene. Therefore, most of the tests, of course, reveal the “omicron”.
According to experts, there is no need to establish the sequence of nucleotides in the DNA molecule of all infected citizens (in science this is called “sequencing” – Ed. Approx.). Currently, you can focus on those arriving in the country, especially from regions that are dangerous for coronavirus.
This opinion, for example, is confirmed by the work of the German virologist Sandra Cisek. The other day she published the results of laboratory PCR tests, which revealed the “omicron” -strain in the samples of a resident of the federal state of Hesse who returned from South Africa. Six antigen tests from three different manufacturers were able to identify the virus.
The sensitivity of antigenic rapid tests that detect coronavirus proteins in the nasal smear also did not decrease with the appearance of the omicron. Abbott was one of the first to report this. Her rapid tests, like PCR tests, are not based on the detection of the S-protein gene, so their performance has not decreased.
“To date, we have carefully analyzed over 1.4 million sequences, assigned to 63 different variants, and none have affected the ability of our diagnostic tests to detect the virus. This includes the sequences of the Omicron strain,” Abbott said in a statement.
According to representatives of this company, which offers tests not only from Russian, but also foreign manufacturers, Osang Healthcare and Rapigen (South Korea) also announced successful recognition of omicron by antigen tests.
Rapigen announced that its antigenic tests successfully recognize variants of the coronavirus such as alpha, beta, epsilon, eta, kappa, lambda, zeta, gamma, delta , delta plus (AY.1), mu and omicron. It is especially noted that mutations in the N-protein of the omicron do not affect epitopes (a part of the antigen macromolecule that is recognized by the immune system – prim. row.), important for the identification of virus strains.
By the way, according to Western media reports, the chief national infectious disease specialist of the United States, Anthony Fauci, said that the effectiveness of rapid tests allows them to be used at home, for which the US government will purchase a large batch of such test systems.
In general, on the eve of the upcoming New Year holidays, the issue of operational testing for coronavirus for many countries is almost becoming a matter of state security. And since government experts are satisfied with the results of studies on the effectiveness of rapid tests to identify new strains (including omicron), the solution to this issue is seen precisely through the dissemination of rapid tests among the population.
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