This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

While coronavirus case numbers continue to decline in Los Angeles County, officials on Monday warned that the new omicron subvariant has been increasingly popping up.

The more infectious subvariant, BA.2, is gradually spreading in the county.

During the last week of February, the new variant accounted for 6.4% of all sequenced specimens in L.A. County. That’s an increase from the week before, when that number was 4.5%.

L.A. County Director of Public Health Barbara Ferrer said this means that the region needs to be prepared “for the possibility of more cases in the near future.”

“And while discouraging to face this possibility, the best way to blunt another surge in cases from increasing hospitalizations and deaths is to increase vaccination and booster coverage,” Ferrer added in a statement.

Concerns over the new subvariant are emerging as the U.S. relaxes COVID-19 restrictions on local, state and federal levels — though California officials have signaled that they would reinstate restrictions if necessary.

Given the increase of BA.2, Ferrer urged unvaccinated residents to use the next couple of weeks to get their shots.

“Waiting until we start seeing increases in cases is not optimal, since once there are more people testing positive, there is already more community transmission,” Ferrer said.

L.A. County is now recovering from an omicron-fueled surge that sent infection numbers skyrocketing to record highs during the winter.

With the virus loosening its grip on the county in recent weeks, officials have eased vaccine verification rules and allowed residents to shed their masks in most indoor places.

It remains unclear how the new omicron subvariant will impact the progress made so far.

BA.2 now accounts for about a third of all sequenced specimens nationally, according to the Centers for Disease Control and Prevention.

The Northeast U.S. is seeing higher percentages of BA.2 than other regions, with the subvariant accounting for nearly 30% of cases in New York City, 20% of the cases in the Midwest and 20% in Chicago.

While L.A. County’s rate is lower than that of other cities, the numbers are following a similar pattern seen when previous variants that emerged and swiftly spread throughout the region, county Department of Public Health officials said.

A COVID-19 resurgence in parts of Europe has also raised worries that another surge is on the way for the U.S.

“Remember that the pandemic — while we’re in a lull right now — is not over,” UCLA Professor of Epidemiology Dr. Anne Rimoin told KTLA.

Rimoin said more variants will emerge, and some will be more serious than others.

“What we’re seeing in the U.K. is a significant increase in cases,” Rimoin said. “We’re not seeing an increase in severity, which is great news.”

However, the professor warned that the U.S. could begin seeing the same trends Europe is seeing.

“We know that what happens in the U.K., or in Europe, eventually happens here a few weeks later,” Rimoin said.

The nation’s top infectious disease expert, Dr. Anthony Fauci, has said that he wouldn’t be surprised if case numbers began to climb in the U.S. in the next few weeks.

“I would not be surprised at all, if we do see somewhat of an uptick,” Fauci told the Washington Post. “The extent of it and the degree to which it impacts seriousness of disease like hospitalizations and death remains to be seen. I don’t really see, unless something changes dramatically, that there would be a major surge.”

Still, officials are urging residents to roll up their sleeves and get innoculated if they haven’t already.

“Residents should be prepared to mitigate the risk of increased transmission associated with this more infectious subvariant,” health officials told residents Monday.

The worry is for those who haven’t been vaccinated and boosted.

So far, 83% of L.A. County residents aged five and older have received at least one dose of the COVID-19 vaccine. About 75% were fully vaccinated.

Just 57% of eligible residents aged 12 and older have gotten the booster.

Gaps in vaccine coverage vary by race, ethnicity, age and location, with many “many pockets of vulnerability” across the county, health officials said.

Parts of the San Gabriel Valley, South Central L.A. and the Antelope Valley have lower vaccination coverage than other areas in the county.

And so far, only 30% of children between the ages of 5 and 11 are fully vaccinated.