New COVID Strain 'Most Transmissible' Yet: What To Know About XBB.1.5 In NJ

NEW JERSEY — The new coronavirus subvariant XBB.1.5 — one global health officials call the “most transmissible” descendant yet of the omicron variant — could fuel new cases of COVID-19 in New Jersey.

In the United States, XBB.1.5 was responsible for more than 27 percent of cases last week, up from about 2 percent the first week of December, according to the CDC. But it's even more prevalent in New Jersey, comprising 72.7 percent of cases last week. (The CDC produces variant-proportion data by "region." New Jersey's region also includes New York, Puerto Rico and the U.S. Virgin Islands.)

“That’s a stunning increase,” White House COVID-19 response coordinator Dr. Ashish K. Jha tweeted last week of the rapid rise in XBB cases, at the same time telling Americans it’s “critical” that Americans are up-to-date on bivalent booster shots.

Only about 15 percent of eligible Americans have gotten their bivalent booster shots. That includes 38 percent of older Americans, who are most at risk of a serious illness.

Meanwhile, only 15.5 percent of eligible New Jerseyans received the bivalent dose, while 83.4 percent of people 5 and older completed the initial COVID vaccination series. That means roughly 5.6 million New Jersey residents — more than half of the state's overall population — who completed the initial series did not receive the bivalent booster

“For folks without a very recent infection or a bivalent vaccine, you likely have very little protection against infection. And for older folks, diminishing protection against serious illness,” Jha tweeted.

The subvariant emerged as New Jersey continues to weather the "tripledemic" — the simultaneous threat of COVID-19, flu and respiratory syncytial virus (RSV) that has filled emergency rooms and pediatric departments around the nation.

New Jersey's intensive care units continue to fare better than the nation's as a whole, but the state still faces challenges. Within a week, the state endured 96 COVID deaths, its highest total of COVID hospitalizations since early February, and the flu season's third pediatric fatality from influenza-related illness, according to health officials.

As of Thursday, the CDC recommended wearing masks within public, indoor spaces in every New Jersey county. Read more: All Of NJ Should Mask Up As 'Tripledemic' Spurs Hospitalizations: CDC

Hospitals throughout the state had 1,776 patients with confirmed or suspected COVID as of Friday — the New Jersey Department of Health's highest tally since Feb. 8, when last winter's omicron wave waned.

Unlike the omicron wave, the recent increase in COVID hospitalizations has been gradual, with steady rises since the New Jersey Department of Health reported 976 patients on Nov. 18. Last winter's surge brought a greater spike of COVID hospitalizations during the same timeframe, going from 765 patients on Nov. 17, 2021 to a Jan. 11 peak of 6,089 hospitalizations.

XBB.1.5 combines traits of previous mutations, which health experts say make it spread more easily, even among previously infected or vaccinated people.

It’s more transmissible because of the mutations it has that allow the “virus to adhere to the cell and replicate easily,” Dr. Maria Van Kerkhove, technical lead on COVID-19 for the World Health Organization, told reporters last week.

There is no evidence XBB.1.5 is more severe than other omicron strains, Van Kerkhove said.

“We are concerned about its growth advantage, in particular in some countries,” Van Kerkhove said, singling out Europe and the Northeast U.S., “where XBB.1.5 has rapidly replaced other circulating variants.”

Jha said he’s concerned about the subvariant, but, “Am I worried this represents some huge setback?” he said. “No.”

Besides getting a bivalent vaccine, Jha said Americans should take COVID-19 tests before large gatherings or if they will be seeing someone who is vulnerable. Also, he said, wear high-quality facemasks in crowded indoor spaces, and “work to improve ventilation/filtration in indoor spaces.”

Anyone showing symptoms should get tested right away. The Paxlovid Molnupiravir treatments “should work fine based on what we know,” he said.