The health government says it has followed a handful of new variants of SARS-CoV-2 that are spreading across the country, adding the XBB. 1. 16 subline. This strain has been dubbed by some scientists on social media as “Arcturus,” much to the frustration of some fitness officials.
Scientists say XBB. 1. 16 is similar to previous strains that have recently been dominant in the United States, adding the XBB. 1. 5 variant that caused the new wave of infections this fall and winter, and does not appear to cause any worsening or other symptoms compared to other variants.
“We haven’t noticed a dramatic replacement at the peak since that shift from Delta to Omicron,” said Dr. Brown. Natalie Thornburg of the Centers for Disease Control and Prevention at an FDA vaccine meeting on April 27.
Thornburg said XBB. 1. 16 had only a handful of mutations in the SARS-CoV-2 spike protein compared to its recent predecessors, fewer than the more than two dozen adjustments noted when the original Omicron strains outperformed other earlier variants in the pandemic.
XBB. 1. 16 may be on track to overtake another variant called XBB. 1. 9, which accounts for 12. 7% of viruses circulating in the United States. It could be to spice up each of them this fall.
“We continue to see substitutions build up in the spike protein over time. And that can be described as drift, which happens more slowly,” Thornburg said.
Here’s the latest on what we know about XBB. 1. 16.
Weekly projections released April 28 by the CDC estimate that XBB. 1. 16 has more than 11. 7% of the viruses circulating nationally. There have been more than 88,000 cases reported nationally in the past week, but CDC officials said cases are particularly underestimated because of viruses in the home. Tests and states no longer report data.
Regionally, XBB. 1. 16 has risen to more than 1 in 10 infections in several regions of the country. It represents the highest estimate of cases at 15. 6% in the region covering Arkansas, Louisiana, New Mexico, Oklahoma and Texas.
Among travelers at foreign airports, the CDC program detected XBB. 1. 16 in about 1 in five pooled positive samples from flights that arrived in early April.
Globally, India, which has noticed a wave of new infections in recent months, has reported the highest percentage of XBB. 1. 16 sequences to global virus databases. The strain has been dominant there since February.
Health governments around the world, in addition to the World Health Organization, have downplayed claims that XBB. 1. 16 causes new or worse symptoms than other variant strains of Omicron that caused past waves.
In India, where XBB. 1. 16 had increased, the WHO reported on April 17 that hospitalizations and other measures of disease severity were no worse than other circulating variants.
Some have indicated that “conjunctivitis”, also known as conjunctivitis, is a possible new symptom through XBB. 1. 16. But at a press conference on April 18, WHO officials described it as a “known symptom that is already a component of COVID. “
Doctors have reported that conjunctivitis appears as the only symptom of COVID-19 in patients since 2020. It may also appear before other more common symptoms.
“I am aware of any primary changes in the symptomatology of this variant, but we are seeing features related to increased transmission capacity,” WHO’s Dr. Mike Ryan told reporters.
The WHO has described the variant’s expansion merit as only “moderate” compared to other strains. Since it was first reported in early January, the variant has gradually increased worldwide.
“What we’re seeing is some sort of estimated expansion advantage, evidence of immune evasion characteristics, so this variant may spread more globally and lead to increased incidence,” Ryan said.
Preliminary analyses suggest there is “little difference” in the ability of vaccine antibodies to repel XBB. 1. 16 to earlier XBB strains, the United Kingdom reported April 21. 17 discovered a “comparable” ability to evade past infections.
Although XBB. 1. 16 was discovered as the outbreak of infections in India, it is still unclear what the precise role of mutations in this variant was in driving this increase. India experienced a “strikingly similar” increase at the same time in 2021, Swiss variant trackers noted on April 27, making it difficult to determine to what extent this is just a “seasonal effect. “
For now, COVID-19 measures continue to decline in the United States. The speed of hospital admissions with the virus is hitting some of the record lows seen in the spring of 2021 and 2022, before new outbreaks occur over the summer.
“It hasn’t yet fallen into a precise seasonal trend, however, in recent years we’ve noticed an increase in expired summer, early fall or mid-summer, early fall, and then some other increase in holidays. “Thorburg said.