“The Nightmare”: the other variant of Omicron that torments doctors and scientists

In the United Kingdom, Europe and North America, the prevalence of BQ.1 It is increasing rapidly. The latest data from National Statistics Office (ONS) from the United Kingdom reported that BQ.1 subspecies (including similar BQ.1 and BQ.1.1) accounted for 16.7% of infections. In the United States, it is BQ.1 and BQ.1.1 together About 35% of infections.

XBB seems to be more popular in Asia. Yes good ONS data indicate that it accounts for only 0.7% of infections in the UK, in Singapore, about 58% One of the recently serialized cases is the XBB. But while the XBB sequence are increasing globallyIt seems that cases of XBB in Singapore now I started to fall.

Scientists take a closer look at different areas where both variants are traded to see which one has the competitive advantage.

In his article, Easton notes that Omicron’s variants are successful in part because Several common mutations in the spike protein receptor-binding domain (A protein on the surface of the virus that allows it to stick to our cells.)

The main difference between BQ.1 and XBB is the number of mutations and their location in the receptor-binding domain. This part of the protein is necessary for the virus to infect our cells and is also a target for antibodies that are an important part of the immune response.

A recent preprint study (a non-peer-reviewed study) suggests that there are mutations within of the receptor binding domain I can help XBB to escape neutralizing antibodies generated by Covid vaccines or infection of previous Omicron offspring, including the parental strains BA.2 and BA.5. This proto-XBB is one of the most antibody-evading coronavirus strains we’ve seen.

Cornelius Romer, a computational biologist in Switzerland, suggest that Several of these specific changes in the receptor-binding domain can increase virus growth efficiency, or “Fitness“. The idea is that more changes will allow it to stick to human cells more tightly, giving it a better chance of infecting that cell.

According to Roemer’s model, BQ.1 is a level-five variant, with five mutations from a list of 21 major mutations that increase SARS-CoV-2’s ability to stick firmly to human cells. XBB is currently the only variant at Level 7, with seven of the 21 major mutations.

At this time, this is just an observation and has not been officially published or peer reviewed. however, other scholars They’ve also noted the XBB’s clear growth advantage over other variants.

But it’s not just mutations in the receptor-binding domain that can give XBB an advantage. XBB also contains mutations in another part of the spike protein called the N-terminal domain.

The immune system also targets the N-terminal domain with antibodies and people who have recovered from infection BA 2 s BA 5 Development Particularly strong immune responses to this part of the spike protein. Preliminary evidence suggests that XBB is also very effective evade these antibodies. This means that a previous infection with BA.2 or BA.5 may not protect you from XBB.

By these measures, XBB is likely to be more immune to evasion than BQ.1 and parental BA.5, and It could have a growth advantage that could increase the spread of the virus.

The good news is that based on Singapore data, it is estimated that XBB has 30% less risk of hospitalization compared to BA.5. But we don’t have data to support this from other countries yet, so this may change as XBB becomes popular.

We may be facing a double wave of infections in the UK: a wave of BQ.1 infections from Europe and the US, before a second wave of XBBs from Asia. We don’t know if BQ.1 will provide any protection against XBB. Only time will tell if the XBB will outpace the BA.5 or BQ.1, or if another variant is waiting in the wings.

However, in Singapore, which is at the peak of cases due to XBB, it is estimated that in the next few days new infections will start to wane. World Health Organization (Who is the) also had a reassuring message at the end of October regarding the seriousness of XBB’s injuriesindicating that no substantial changes were observed with respect to the other sublines, although they appeared to be more infective.