Omicron “New Player” CH.1.1 Appeared in the United States!! Its Potential Mutation is Worrying!!

At present, a “new player” of the novel coronavirus has emerged in the United States. It is a subvariety of Omicron called CH.1.1., which belongs to a branch of the mainstream strain BA.2.75.

CH.1.1 was named “Orthrus” (two-headed dog in Greek mythology) by Australian virus expert Mike Honey. Studies have shown that it may be more contagious and immune-evading than other subvariants, and may cause more severe disease.

According to the US Centers for Disease Control and Prevention (CDC), Up to local time January 28, CH.1.1 accounted for 1.5% of US cases, ranking fifth in proportion.

Judging from the data, the Omicron subvariant XBB.1.5 has spread rapidly in the United States and has replaced BQ.1.1 as the number one new coronavirus variant in the United States, accounting for 61.3% of the total cases.

Infection levels climbing

Not much is known about this relatively new variant. In fact, CH.1.1 has been spreading around the world since last November, and infection levels have been climbing everywhere.

The spread of CH.1.1 has risen sharply since November and now accounts for about 10% of daily samples tested worldwide, according to outbreak.info, a coronavirus information resource.

CH.1.1 emerged last fall in Southeast Asia and is now responsible for about a third of infections in parts of New Zealand, according to a preprint paper published last week by researchers at Ohio State University. Hong Kong and Papua New Guinea account for about a quarter.

A report this week from the UK Health Security Agency (UKHSA) suggested that CH.1.1 may have accounted for 23% of all new crown cases in England, and may account for 100% of new cases in some areas.

Dreadful mutation

The paper states that CH.1.1 found a mutation called L452R in the S protein. This mutation, which is not normally seen in the amicron variant, has been seen in the delta strain, which is worrying.

This also means that CH.1.1 may be more infectious than other Omicron strains.

In addition, the paper also mentioned that the virus may cover some of the antibodies produced by previous infection or vaccination, resulting in stronger immune evasion and leading to more severe disease.

The researchers conducted related experiments on the immune evasion ability of CH.1.1. The experiment sampled the serum of 14 medical staff (these medical staff received 2 to 4 doses of the original vaccine and Omicron booster injection). By testing the neutralizing effect of serum and CH.1.1, the researchers found that antibodies against CH.1.1 produced in serum were 17 times less than those against BA.4 and BA.5.

CH.1.1 deserves attention

Cornelius Romer, a computational biologist at the University of Basel in Switzerland, noted in a report last week that CH.1.1, like XBB.1.5, is highly transmissible, with infection levels doubling roughly every two weeks or so.

The World Health Organization (WHO) showed in a report on Wednesday that the CH.1.1 virus variant is one of the viruses that the WHO monitors.