المتغيرات الجديدة لفيروس كورونا أوميكرون
April 13, 2022 - اكتشف علماء جنوب أفريقيا نوعين مختلفين من فيروس اوميكرون. السلالات BA.4 و BA.5 تنشط في بوتسوانا وبلجيكا وألمانيا والدنمارك والمملكة المتحدة.
The World Health Organization (WHO) said on Monday (April 11, 2022), it is tracking a few dozen cases of two new sub-variants of the Omicron strain of the coronavirus.
The WHO has added BA.4 and BA.5 variants of the original BA.1 Omicron variant to its list for monitoring. The WHO has cited “additional mutations that need further studies to understand their impact on immune escape potential.”
According to Tulio de Oliviera, the Director of the Centre for Epidemic Response and Innovation (CERI) in South Africa, BA.4 and BA.5 show additional mutations to the spike protein.
“Given the very low infections, hospitalisations and deaths in South Africa, we are alerted about the continued evolution,” de Oliveira said.
Viruses constantly mutate, but only some mutations affect their ability to spread or evade prior immunity from vaccination or infection.
In a paper published on bioRxiv.org, Suresh Kumar of Management & Science University in Malaysia, Kalimuthu Karuppanan, and Gunasekaran Subramaniam of Oxford University assess mutations to Omicron sub-variants.
The paper, which has not been peer-reviewed, identifies 145 mutations in the genomes of seven Omicron variants. These genetic changes are far more than all other Variants Of Concern (VOCs) identified by the WHO combined.
The five VOCs, including the original Omicron (B.1.1.529), show 75 genetic mutations. Most changes are to the spike protein gene and receptor-binding domain.
Scientists around the globe are working to determine how these mutations, particularly in the spike protein, will impact transmission, infection, and the effectiveness of the existing vaccines and antibodies.