XBB.1.5 new variant is more contagious but not more dangerous: Experts - USA TODAY

The latest COVID-19 variant to expanse crossed the country, XBB.1.5, doesn't look to origin much superior illness than its predecessors, experts say.

But it appears to be about 5 times much contagious than an earlier omicron variant, which was five times much contagious than the archetypal virus, said Mehul Suthar, who studies emerging viral infections astatine the Emory University School of Medicine successful Atlanta. "The numbers commencement adding up."

As of Dec. 31, XBB.1.5 accounted for much than 40% of cases in the United States, up from astir 1% little than a period earlier, according to the Centers for Disease Control and Prevention.

Still, vaccines stay effectual astatine preventing terrible illness and decease and the antiviral Paxlovid, fixed successful the archetypal fewer days aft infection, "dramatically reduces progression to hospitalization," said Dr. Daniel Griffin, an infectious illness specializer astatine Northwell Health successful New York.

"We're not backmost successful the acheronian days of aboriginal 2020," helium said. 

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COVID vaccines and caller variant XB.1.5: What to know

The superior interest with immoderate caller variant is whether vaccines and treatments volition stay effective. 

"The vaccines are holding. That's good," said Dr. Jeremy Luban, an adept connected viruses astatine the University of Massachusetts Chan Medical School.

But "anytime you person a caller carnal that spreads similar this, idiosyncratic to idiosyncratic truthful rapidly, it puts a large accent connected our infrastructure – aesculapian facilities and unit who are chronically short-staffed. That's a occupation for everybody," helium said.

Suthar led a study, published in December, showing that COVID-19 booster shots, designed to people 2 antithetic variants, inactive supply extortion against this caller 1 – and amended extortion than a vaccine directed astatine conscionable the archetypal virus. "I deliberation we're heading successful the close direction," helium said. 

Unfortunately, arsenic has been existent for astatine slightest the past twelvemonth with omicron and its subvariants – including this one – the vaccines aren't arsenic bully at preventing corruption and mild disease. 

And the aesculapian explanation of "mild" whitethorn not lucifer the mean person's, Griffith said. "People are inactive beauteous miserable," helium said, adding that respective patients person complained that a caller corruption was worse than a erstwhile 1 oregon worse than they've felt from astir thing other successful their life. 

Why is XBB.1.5 spreading truthful quickly?   

The caller variant is spreading fast, Luban said, for 1 of 3 reasons oregon – much apt – a combination:

• Recent vacation gatherings and question exposed much radical and fewer are wearing masks.
• This variant whitethorn beryllium amended astatine transmitting from person-to-person. It appears to hindrance adjacent much tightly than earlier variants to the body's ACE-2 receptors.
• It seems to beryllium much resistant than earlier variants to the immune system's antibodies.

In New York, XBB.1.5 is the immense bulk of COVID cases

In the northeast, peculiarly New York, XBB.1.5 now accounts for the immense bulk of COVID-19 infections, Griffin said. 

At Northwell Health – which serves New York City, Westchester and Long Island – hospitalizations for COVID-19 are rising, but inactive conscionable fractional the level of this clip past year. As of Tuesday, determination were 783 patients hospitalized astatine Northwell with COVID, with 10% successful intensive care, up from 545 cases a period ago and 467 cases arsenic of Nov. 3.

Why caller variants airs a threat

As of aboriginal December, XBB and its subvariant made up less than 5% of cases, portion variants BQ.1 and BQ.1.1 accounted for much than 60%. They present marque up astir 45%. 

The large interest is that a aboriginal variant mightiness beryllium much dangerous, Luban said.

"Anytime the microorganism spreads truthful accelerated and replicates truthful overmuch ... could it alteration successful immoderate mode that volition impact the pandemic? We can't foretell those things," helium said.

CASES EXPLOSE IN CHINA: What that could mean for the United States

And adjacent now, portion vaccines and antivirals inactive enactment against them, monoclonal antibodies bash not. Monoclonals were adjuvant earlier successful the pandemic astatine preventing high-risk radical from ending up successful the infirmary oregon adjacent getting infected astatine all.

"People whose immune strategy needs help, they're conscionable retired of luck (now)," Luban said.

Luban and the others remain concerned astir the ongoing dispersed of COVID-19 successful China. On Dec. 1, China relaxed its long-held "zero COVID" policy, and cases are believed to beryllium exploding there, though the authorities has not released elaborate information.

LATEST: US volition necessitate COVID-19 investigating for travelers from China

Why you should inactive debar getting infected  

There's nary uncertainty that it's safer to debar getting infected astatine all, the experts said. Suthar, Griffin and Lubansupport vaccination with astatine slightest 3 doses and each 3 said they inactive disguise erstwhile successful public, indoor spaces.

"The 'it's OK if I get infected' cognition is not the astir viable," Suthar said.

Every infection, adjacent aft vaccination oregon a erstwhile infection, increases the hazard for agelong COVID – potentially debilitating symptoms that tin linger for months oregon longer.

Dig Deeper

• What causes agelong COVID and its unusual array of symptoms? 
• Experts interest wherever the adjacent pandemic volition travel from – and if we'll beryllium ready
• White House announces much prevention efforts, including escaped tests

Contact Karen Weintraub astatine kweintraub@usatoday.com.

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