There are growing signs that Omicron’s BA.2 subvariant is on the rise, even as the daily number of reported coronavirus cases continues to drop in California.
It is not yet known whether BA.2, which is 30% to 60% more contagious than the original Omicron variant that swept through California during the winter, will be able to cause another spike. But given how the latest strain has upended trends in other parts of the world, many public health officials are urging caution.
This is what you need to know:
The panorama
The World Health Organization (WHO) reported this week that coronavirus cases were on the rise again around the world. “After a steady decline since the end of January 2022, the number of new weekly cases grew for the second consecutive week, with a reported rise of 7%” from March 14 to 20 compared to the previous week, the WHO noted in a report issued Tuesday.
Across the United States, health officials are also noticing an increase in the proportion of new coronavirus episodes linked to BA.2.
Nationwide, BA.2 comprised approximately 35% of the samples tested between March 13 and 19. The week before, it accounted for 22%, according to data released Tuesday by the US Centers for Disease Control and Prevention (CDC).
In the Southwest of the country, which includes California, Arizona, Nevada and Hawaii, BA.2 accounted for about 41% of coronavirus samples. The week before, 28%.
For the first time, BA.2 is now believed to be the dominant subvariant in the Northeast, comprising more than half of the cases analyzed in New York, New Jersey, and New England.
There are signs that weekly coronavirus episodes have stopped declining in New York. For the week ending Monday, there were 82 cases per week per 100,000 residents there, down from a rate of 58 the week before, according to Johns Hopkins University.
The California Perspective
For now, weekly coronavirus cases are holding steady nationally and in California, and are continuing to decline in Los Angeles County.
California saw 3,000 to 4,000 cases per day, or about 60 to 70 cases per 100,000 people.
Los Angeles County also reported that its overall weekly coronavirus episodes continue to decline, at least when subtracting a buildup of previous events during Omicron’s peak.
On Tuesday afternoon, Los Angeles County hit a long-awaited goal for health officials: fewer than 730 cases a day for the past week, or about 50 a week per 100,000 residents, according to a Times analysis of county data. The number indicates a moderate level of transmission. Reaching that goal is exactly in the range predicted by Los Angeles County Public Health Director Barbara Ferrer, who noted in February that she suspected the county would reach the point of fewer than 730 cases per day in mid- to late-2019. March.
But the increasing prevalence of BA.2 in many regions, Ferrer said, “reminds us to remain vigilant and prepared for the possibility of more cases in the near future.”
“While facing this prospect is daunting, the best way to mitigate another spike in cases from rising hospitalizations and deaths is to increase vaccination and booster coverage,” he said in a statement. “Given the compelling evidence that vaccines continue to protect against all variants and their wide availability, residents and workers are urged to use the next two weeks to catch up on their vaccinations. Waiting until we start to see increases in cases is not optimal.”
Orange County’s coronavirus case rates are particularly low right now. According to data released Tuesday by health officer Dr. Regina Chinsio-Kwong, the area reports about 26 cases a week per 100,000 residents. Also a high vaccination rate for older people; more than 95% who received at least one dose.
Spring surge?
Dr. Robert Kim-Farley, an epidemiologist and infectious disease expert at the UCLA Fielding School of Public Health, expects coronavirus cases to level off or rise modestly, but nothing like Omicron’s most recent spike.
Kim-Farley suspects that California will not be affected by BA.2 because many people have a reasonable degree of immunity, either from vaccinations or from surviving an infection from the earlier subvariants (BA.1 or its descendant, BA. 1.1). All of that “will turn off the effect of BA.2,” she noted.
The doctor also expects weekly hospitalizations and deaths from COVID-19 to continue to fall, as the availability of anti-COVID-19 drugs such as Paxlovid grows. Instead, he would be more concerned with a new variant that was even more transmissible and capable of overcoming the immunity provided by vaccination or previous infection. “That’s always the wild card that could potentially end up in major trouble,” he said.
It is still important, the doctor added, that people who have had COVID-19 infections get vaccinated, because the strength and duration of natural immunity appears to be less than through dosing and boosting.
How to prepare
Experts consider it prudent to be prepared for a possible increase in coronavirus transmission with up-to-date vaccines and boosters; comply with California’s strong recommendation to continue wearing masks in closed public places and get tested before and after gatherings.
Chinsio-Kwong urged residents not to be too complacent about official reports of low case numbers, noting that many people now take tests with home kits, the results of which are not shared with the government. “Although we may not have a mask mandate in our county, it is still very important to take precautions,” Chinsio-Kwong stressed. California health officials continue to strongly recommend the universal use of masks in closed public places.
That also includes getting a booster shot if you’re eligible, Chinsio-Kwong added. Pfizer-BioNTech vaccine recipients age 12 and older, and anyone who has been vaccinated with Moderna, are eligible for a booster five months after completion of the primary series. Those who received the Johnson & Johnson single dose can receive their booster two months later.
“The most protected are those who are fully vaccinated. So get the booster,” Chinsio-Kwong said.
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