A NEW RANGE OF OMICRON Appears

• New strain CH.1.1, also called Orthrus, discovered in 60 countries, has the ability to evade immunity to a certain extent.

- CH.1.1 developed from variant BA.2.75, first appeared in Southeast Asia in the autumn and winter of 2022 and spread to many countries around the world. This is responsible for more than 25% of infections in the UK and New Zealand, according to a report last week by Ohio State University, USA. Mutations currently account for 1.5% of infections in the US.

- The prevalence of CH.1.1 has increased sharply since last November, accounting for about 10% of nCoV samples sequenced every day globally, according to the public database on Covid-19. On February 1, the World Health Organization (WHO) said it was closely monitoring this mutation.

- Currently, scientists do not have much information about the new strain, but like other subtypes of Omicron, it is highly contagious. The Ohio State researchers found that CH.1.1 also binds well to ACE2 receptors, the site where the virus attaches to infect cells. As such, it has the ability to evade vaccine-generated immunity and previous natural infection. At the same time, the mutation is likely to cause more severe symptoms, although the extent is not clear, according to the scientists.

- Unlike the previous sub-versions of Omicron, CH.1.1 carries the L452R mutation, which appeared in the Delta strain - the dominant strain in 2021. This shows that it can compete well with virus strains. circulating in the world.

- To test the virus' response to the vaccine, scientists exposed CH.1.1 in the laboratory to serum from 14 healthcare workers who had received four vaccinations. They found that serum was 17 times more effective than when exposed to BA.4 and BA.5.

- Most of the dominant nCoV strains today are developed from strains BA.5 or BA.2.75 of Omicron. Experts say that people who have been exposed to these two strains may be "temporarily safe" from the new strains.

However, with Covid-19, every rule has exceptions. Japan has just recorded a consecutive BA.5 outbreak, bringing the number of deaths to the highest level in two years of the pandemic.

- The researchers also think that the protective ability of the original vaccines is declining. Experts from Ohio University said that the booster dose may be less effective against CH.1.1 and later strains.

To date, the world has recorded 675 million Covid-19 cases and 6.7 million deaths. Most countries have lifted strict epidemic prevention measures. The dominant strain is BA.5, sublineage of Omicron. However, another sub-variant, XBB, especially XBB.1.5, is spreading so much that scientists worry.

* Source: VNXPRESS Newspaper https://vnexpress.net/xuat-hien-bien-chung-moi-cua-omicron-4566055.html