NEW BA.4 COVID-19 VARIANT REACHES COUNTY

Immune-resistant virus detected as daily new-case totals rise

Ongoing genetic analysis has confirmed that three recent San Diego-area coronavirus infections were caused by the BA.4 variant, one of two rapidly spreading types recently classified as a “variant of concern” by Europe’s main public health authority.

Just last week, the European Centre for Disease Prevention and Control announced the new label based on the demonstrated ability of BA.4 and its cousin, BA.5, to “evade immune protection” whether it was caused by vaccination or prior infection.

The county health department confirmed that genetic sequencing performed on positive test results collected on April 18 and 28, and on May 3 all matched the profile of BA.4. It often takes weeks to analyze samples after they are collected, meaning that it is likely that there are more cases present in the community than have been confirmed, especially as only a sampling of all new cases are analyzed.

Meanwhile, daily new-case totals are on the rise, tracking similar increases observed nationwide. The health department was notified of 1,579 new positives Wednesday, the largest single-day new-case total reported to the public since the 1,712 reported on Feb. 11 during the tail end of the Omicron surge. While the latest total is nearly four times greater than it was one month ago, it re

“These new variants are highly infectious and are f inding their way around immunity from vaccination.” Dr. Robert Schooley, infectious disease expert, UC San Diego

mains much, much smaller than the daily tallies from the most-infectious stretch of the pandemic when more than 10,000 cases were reported daily in mid-January.

Thursday’s starkly higher numbers came alongside some good news: Boosters for kids age 5 to 11 have now been approved by two federal agencies, and a final OK at the state level is expected soon.

Chris Abe, vice president at Rady Children’s Hospital, said there is significant demand for boosters in this age group, and shots are expected to begin going in arms on Tuesday.

“We still have our systems in place, so we should be able to begin doing boosters pretty quickly,” Abe said.

First detected in South Africa, BA.4 and BA.5, both descendants of the Omicron variant that caused last winter’s surge of infections, have proved even better at spreading quickly, about 12 percent more quickly than BA.2, the currently dominant sub-variant that shares the same predecessor.

Omicron showed that while it was better at transmitting itself from person to person, it was less able to cause severe illness than the variants, such as Delta last summer, that came before it. So far, experts say, BA.4 and BA.5 appear to have a similar severity level, with hospitalization and death less likely but still a possibility when large numbers of cases occur in a compressed timeframe.

Dr. Robert Schooley, an infectious disease expert at UC San Diego, said that the competitive advantage that BA.4 and BA.5 enjoy makes it very likely that they will quickly outcompete other circulating SARS-COV-2 types just as Omicron did during the holidays, and likely with similar results.

“I think we may see the current downward trend reverse itself a bit, but I don’t think we’re going to see the explosion of cases that shuts down the ICUs and makes it so we can’t take care of other people who have serious diseases like we had happen last year,” Schooley said.

The big pain point, he added, could be very similar to Omicron’s. During that coronavirus wave, droves of critical health care workers tested positive, having to stay home all at once and causing a massive staffing shortage that contributed to gridlock in many hospital emergency departments.

“These new variants are highly infectious and are finding their way around immunity from vaccination,” Schooley said. “We are still pulling people out of circulation when they get infected, so we could have a strain on personnel to cause operational problems in health care systems, but I don’t think we’ll have a shortage of beds.”

With few still wearing masks and vaccine protection waning, Schooley said it is incumbent on critical personnel to take their own steps now that BA.4 has arrived.

“If you’re doing something that’s less critical, sure, go to the bars and hang out,” he said. “If you’re running a nuclear power station or doing switching for the electric company or working in the hospitals, this is a time, really, to keep your head down and stay uninfected so that we can keep everything going.”

Some Rady employees, Abe said, have already had to take off work due to recent infections even as 7.5 percent of coronavirus tests were coming back positive early this week, about triple the previous positivity rate. While children’s hospitals, Rady included, have seen far lower levels of hospitalizations associated with COVID-19, the rise in cases, the executive said, has bumped up the number of inpatients.

“With this little surge, we’re back to having at least one or two kids in the ICU every day, and anywhere from four to six on our medical floor,” Abe said. “We had been down to one or two with none on some days.”