Updated 12/03/2022 3:19 PM
- According to a Charite study, precursors to the omicron variant existed well before the first detection.
- Development was simply forgotten due to lack of analysis.
- The conclusion of the study: Omikron was not suddenly transferred from the animal kingdom or traced to a so-called immunosuppressed person.
The original coronavirus was followed by alpha, beta, gamma and delta as variants with high transmissibility. Every few months, a new variant appeared, some of which soon became dominant. At the end of 2021, Omikron appeared – and it stayed.
According to a study by Charité Berlin published in the journal “Science”, omicron precursors were already present on the African continent well before the first detection in November 2021. Contrary to what is assumed in widespread hypotheses about the origin, the variant it developed gradually over several months in different countries in Africa. This development was simply overlooked due to lack of analysis.
On 26 November, the World Health Organization (WHO) classified the corona variant B.1.1.529, first detected in South Africa on 9 November 2021, as “of concern”. Despite huge travel restrictions, omicron spread rapidly around the world and caused an extremely large number of infections. By late December 2021, the variant had already displaced the previously dominant Delta virus. To this day, omicron subtypes dominate the infection process worldwide – and are currently undermining China’s Covid-zero strategy.
More than 13,000 samples from 22 African countries underwent a special PCR test
Compared to the original Wuhan Sars-CoV-2, Omicron had an unusually high number of around 30 amino acid changes in the spike protein alone. The large number of genetic alterations led experts to assume that the variant could have developed in a person with HIV or another form of immune deficiency. Another hypothesis assumes that omicrons developed in animals and then returned to humans.
The idea behind the immunodeficiency hypothesis: In people with a weakened immune system, Sars-CoV-2 could have multiplied over many months and changed little by little without ever being deactivated by the immune system. Many HIV patients in Africa are not treated properly, which is why their immune systems are significantly weakened, experts explained. “The many mutations speak for development in patients with HIV,” said SPD health expert at the time, Karl Lauterbach.
For the “Science” study, Charité scientists led by Jan Felix Drexler, together with African cooperating partners, examined corona samples that were collected before the discovery of the omicron in South Africa and after. More than 13,000 samples from 22 African countries underwent a special PCR test. The research team found viruses with specific omicron mutations in 25 people from 6 countries who had already contracted Covid-19 in August and September 2021, months before the first detection in South Africa.
Data show that omicron had multiple progenitors
Furthermore, the viral genome was decoded in approximately 670 samples. Several viruses were found that were similar to omicron, but not identical. “Our data show that omicrons had different progenitors that mixed and circulated in Africa at the same time and for months,” explains Drexler. “This indicates a gradual evolution of the BA.1 omicron variant, during which the virus became increasingly better adapted to existing human immunity.”
The scientists also concluded from the data that omicrons first dominated the infection process in South Africa and then spread from south to north across the African continent within a few weeks.
“The sudden appearance of the omicron is therefore not due to a transfer from the animal kingdom or to development in an immunosuppressed person, even though this could also have contributed to the development of the virus,” Drexler concludes. “The fact that we were blindsided by Omikron is due to the diagnostic blind spot in large parts of Africa, where probably only a fraction of Sars-CoV-2 infections are registered.” (pak/dpa) © dpa