Alarm in the US due to a new variant of covid-19 XBB.1.5 0:45
(CNN Spanish) --
Scientists warn that the XBB.1.5 variant of the coronavirus may be the most transmissible since omicron, which caused strong waves of infections, but indicate that, so far, there are no indications that it causes a more serious disease .
During the month of December, the percentage of new covid-19 infections in the United States caused by XBB.1.5 increased from an estimated 4% to 41%.
Experts have already released some warnings to keep in mind.
Dr. Ashish Jha, the White House response coordinator for COVID-19, said that XBB.1.5 is probably the most capable of breaching our immune defenses and may be the most contagious.
Maria Van Kerkhove, an epidemiologist and WHO technical leader on covid-19, went a little further and assured that the variant —which was first detected in the United States and has spread to at least 29 countries— “is the way most transmissible of omicron to date”.
There's one point the two scientists made: It's not yet clear whether it causes more serious disease.
So far there is no indication that this is the case, so most experts have said that while they expect XBB.1.5 to have the potential to cause more disease, they don't expect those infections to be necessarily more serious.
What we know about the symptoms
"From what is known so far, the symptoms are no different from those of omicron," Dr. Elmer Huerta, a specialist in Public Health, told CNN en Español.
These include sore throat, cough, and fatigue —and less loss of smell and taste compared to the effect of other previous variants such as alpha, beta, gamma, and delta.
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However, "the symptoms take a while to consolidate," he said.
This is linked to how the information is studied: the symptoms are tabulated and entered into databases, and the analysis of these data is not necessarily fast, Huerta explained.
Therefore, for this moment "there is not yet a scientific publication or something that confirms" the question of symptoms.
An update from WHO is expected shortly.
How to take care of ourselves amid the rise of the XBB.1.5 variant
The tools to take care of ourselves have not changed.
Jha pointed out that effective tools to avoid serious covid-19 infections include rapid testing, use of high-quality masks, indoor air ventilation and filtration, oral antiviral pills, and up-to-date vaccinations.
How effective the available vaccines are is another key point.
Dr. David Ho, Professor of Microbiology and Immunology at Columbia University, recently tested in his laboratory viruses designed to have the spikes of the XBB and XBB.1 variants, as well as BQ.1 and BQ 1.1, against antibodies to the blood from people who had been infected, who had been vaccinated with the original and new bivalent vaccines, and who had been both infected and vaccinated.
His team also tested 23 monoclonal antibody treatments against these new subvariants.
He found that XBB.1 was the most elusive of all.
It was 63 times less likely to be neutralized by antibodies in the blood of infected and vaccinated people than BA.2, and 49 times less likely to be neutralized compared with BA.4 and BA.5.
In terms of immune evasion, Ho says, these variants have strayed as far from the antibodies we've made to use against them as the original omicron variant strayed from the covid-19 variants that preceded it by about a year ago.
Ho explained that XBB.1.5's antibody evasion is the same as that of XBB.1, meaning it has the potential to escape protection from previous vaccines and infections.
It is also resistant to all current antibody treatments, including Evusheld.
With reporting from CNN's Brenda Goodman.
