A rapid rise in the latest coronavirus omicron subvariant, XBB.1.5, has made headlines as the winter wave of COVID-19 sweeps across the United States, and the disease could soar again. There is growing concern. But the spotlight is revealing more questions than answers in the early stages of a variant that has been eerily described as one of the most immune-evading omiron variants to date.
Last week, the US Centers for Disease Control and Prevention quietly lowered its prevalence estimates. As reported by Ars and other media outlets, the CDC previously said XBB.1.5 accounted for 40.5% of COVID-19 cases nationwide in the week ending Dec. 31, with the highest prevalence in the Northeast. I was guessing. However, last Friday, the agency used a backlog of sequencing data over the holidays to update its estimates. This indicated that XBB.1.5 accounted for 18% of national cases that week, not 40.5%. The CDC now estimates that in the week ending Jan. 7, he XBB.1.5 accounted for 27.6% of cases nationwide.
The latest estimates show an increase in the variant that was first detected in New York in October. However, this uncertainty has taken a toll on estimating the superiority of infection over other omicron subvariants, with BQ.1.1 still being the most prevalent omicron subvariant, with no cases reported in the United States. account for an estimated 34% of
On Wednesday, the World Health Organization released a rapid risk assessment of XBB.1.5, which “could contribute to increased case incidence” worldwide, but the agency’s overall confidence in the assessment was “low.” ” concluded. WHO said, “As of the date of publication, the available data are from only one country. [the US], and therefore trust in global valuations is low. ”
In addition, the agency found no data on the issue of disease severity from XBB.1.5 infection. There are no known mutations.”
XBB.1.5 was considered to have a ‘moderate’ confidence level in evaluating it as one of the most immunoevasive subvariants of omicron to date. Early laboratory studies using pseudotyped viruses to assess neutralizing antibody responses suggest that XBB.1.5 is as immunoevasive as his XBB.1.
uncertainty
Overall, it’s unclear how XBB.1.5 will play out in the US or worldwide. As Ars reported last week, XBB.1.5 is also spreading in some, but not all, parts of the US where hospitalizations have increased after the holidays.
XBB.1.5 has occurred in many countries outside the US, with the UK having the second highest level of detection. Very low levels have also been detected in Austria, Belgium, Czech Republic, Denmark, France, Germany, Iceland, Ireland, Italy, Netherlands, Portugal, Romania, Slovenia, Spain, Sweden and the European Center for Disease Control and Prevention. (ECDC) reported earlier this week.
The ECDC concurred with the assessment from WHO and noted recent studies suggesting that XBB.1.5 does not appear to be the case. more It is more immunoevasive than its upstream subvariant XBB.1, a hybrid of two BA.2 substrains. However, XBB.1.5 may be better at binding to the human receptor ACE2, a gateway for viral entry into human cells. This “may indicate that the advantage of XBB.1.5 compared to XBB.1 may be caused by its inherent increased contagiousness,” ECDC speculates.
Yet, like the WHO, the ECDC ended with an equivocal assessment of the risks posed by XBB.1.5. “There is a risk that this variant could impact the number of COVID-19 cases in the EU/EEA, but given that the variant is currently present at very low levels in the EU/EEA, we will not ,” the agency wrote. “This assessment involves a high degree of uncertainty due to uncertainties related to variant growth rates.”
Back in the United States, hospitalizations due to COVID-19 increased 15% in the past two weeks and now average more than 46,600 per day, while deaths increased by 50%, according to data tracked by the New York Times. The average is 580 people.
