World Health Organization scientific experts cautioned on Friday that a new coronavirus variation detected in southern Africa was a “variant of concern,” the most dangerous classification the organisation has for such surveillance.
According to the classification, which was issued during an emergency meeting of the health organisation, it is designated for hazardous variations that have the potential to spread swiftly, cause serious illness, or reduce the efficiency of immunizations or therapies. The most recent coronavirus variety to gain this designation was Delta, which exploded in the United States last summer and is now responsible for practically all Covid cases in the country.
According to the World Health Organization, the new strain, known as Omicron, includes a variety of genetic changes that may enable it to spread swiftly, even even among those who have been vaccinated.
Independent scientists agreed that Omicron was a problem that needed to be addressed immediately, but they also noted that additional study would be required to understand the scope of the issue. Despite the fact that certain versions of concern, such as Delta, have lived up to original expectations, others have only had a marginal influence.
Dr. Hanage and other experts believe that vaccinations will most certainly provide protection against Omicron, but they believe that further study is required to understand how much the efficiency of the injections may be diminished.
As the coronavirus replicates in the body of a person, new mutations are continually being produced. The majority of these provide the virus no additional benefit. When potentially harmful mutations do occur, the World Health Organization (WHO) names them with Greek letters to distinguish them from one another. Alpha, the first “variant of concern,” arrived in the United Kingdom in late 2020, and was quickly followed by Beta in South Africa.
Scientists at the Botswana Harvard H.I.V. Reference Laboratory in Gaborone discovered Omicron for the first time when they analysed the genomes of coronaviruses from positive test samples. They discovered several samples that shared around 50 mutations that had never been seen previously in such a combination. In Botswana, six persons have tested positive for Omicron so far, according to a database of variations maintained by a multinational organisation.
Around the same time, researchers in South Africa were investigating a cluster of cases in the region of Gauteng when they came upon Omicron. As of Friday, they have identified 58 Omicron samples in the variation database, according to the researchers. Tulio de Oliveira, the director of the Centre for Epidemic Response & Innovation in South Africa, said during a press briefing on Thursday that “near to two or three hundred” genetic sequences of Omicron patients will be disclosed in the next few days.
Researchers discovered more than 30 changes in a protein called spike that is located on the surface of the coronavirus, according to the findings. During a Covid-19 infection, the spike protein is the primary target of antibodies produced by the immune system to combat the infection. It was feared that Omicron’s spike would be able to resist antibodies created by either a prior infection or a vaccination because to the large number of mutations found in it.
Dr. de Oliveira and his colleagues devised a rapid method of determining the rate at which Omicron was spreading in South African populations. Despite the fact that sequencing the full genome of a virus is time-consuming, the scientists were able to identify Omicron using a conventional nasal swab test known as the P.C.R. test.
The tests are quick because they only search for two of the coronavirus’s 29 genes — the spike gene and another gene known as nucleocapsid — in the blood sample being tested. Omicron no longer tests positive for the spike gene as a result of the additional mutations it has acquired. In order to find samples that tested positive for nucleocapsid but negative for spike, researchers might simply check for samples that tested positive for both.
However, it was discovered that spike-negative samples were increasing in number across South Africa, indicating that Omicron had a competitive edge over Delta, which had previously been the dominant variety in the nation.
The European Union and the United States and Canada have been among the countries that have prohibited planes entering from South Africa and numerous other African countries. However, Omicron has previously been discovered in Hong Kong and Belgium, and it is possible that it is present in other nations outside of Africa.
The virus may have remained in that individual for months rather than being swept out in a couple of days, during which time it developed the capacity to avoid antibodies. “This virus has been exposed to a large number of antibodies,” Dr. Hatziioannou said.
Dr. Hatziioannou is afraid that Omicron will be able to avoid some of the antibodies that patients have acquired either via vaccination or from Covid-19 infections as a result of this overlap. Omicron will also be resistant to several monoclonal antibody therapies, according to her, since its spike protein is shielded from these drugs, according to her predictions.
Even if Omicron proves to be more contagious than other variants, Dr. Hanage believes that vaccines will continue to be important tools in the fight against it, both in terms of slowing its spread and increasing the likelihood that people who do get sick will only have mild Covid-19 symptoms rather than needing to be admitted to the hospital.
