New COVID variants are on the rise
Monoclonal antibody therapies may be less effective against dominant BQ.1 and BQ.1.1
Two new COVID-19 variants are on this rise this holiday season, and experts say they could be cause for concern for people with compromised immune systems.
The BQ.1 and BQ.1.1 subvariants of omicron now account for 49.7 percent of all new coronavirus cases nationwide, according to the latest update from the U.S. Centers for Disease Control and Prevention. The share is even higher — 58.1 percent — in the CDC region that includes Texas and four other states.
Both subvariants are descendants of BA.5, the omicron subvariant that led to a surge in cases over the summer. BA.5 now accounts for 24 percent of new cases nationwide and 31 percent in the CDC region that includes Texas.
Like BA.5, both of the new subvariants appear to be highly transmissible and more capable of evading the protection offered by a vaccine or a prior infection. Fortunately, at the moment they do not appear to be causing more severe illness, said Dr. Robert Atmar, a professor of infectious diseases at Baylor College of Medicine.
“What I’ve seen so far is that it has been similar in severity to what we’ve seen with some of the earlier omicron variants, which is to say that it’s been less likely to cause severe disease,” he said.
At the moment, the two new subvariants have not led to a steep rise in infections in the Houston area. Data released Tuesday showed Texas Medical Center hospitals admitted an average of 56 new COVID-19 patients per day last week, nearly identical to the 55 new patients per day they admitted one week earlier. The positivity rate — or the percentage of people who test positive after taking a COVID-19
test — was 3.2 percent last week, up from 2.8 percent one week earlier.
However, the amount of virus detected at the city of Houston’s wastewater treatment plants, which has been a reliable indicator of community spread, increased last week to 134 percent higher than a baseline established in June 2020. It had been 75 percent one week earlier.
“We’re monitoring, very closely, the situation,” said Dr. Luis Ostrosky, an infectious diseases specialist at UTHealth Houston and Memorial Hermann. “It’s ticking up, the wastewater and positivity rate. But so far we have not seen an increase in the number of hospitalizations.”
The bivalent COVID-19 vaccine boosters, which are designed to provide better protection against the omicron variant and its BA.5 and BA.4 subvariants, should continue to offer protection against BQ.1 and BQ.1.1, Atmar and Ostrosky said. Pfizer and Moderna each released statements saying their bivalent shots generated improved immune responses to the new subvariants.
“Early, real-world data with humans is showing pretty strong responses,” Ostrosky said. “Pretty good protection.”
Both Atmar and Ostrosky said the biggest concern related to BQ.1 and BQ.1.1 is the fact that studies have shown monoclonal antibody therapies that have been used to prevent and treat COVID-19 may be ineffective against the two new subvariants.
The CDC warned the two new subvariants appear to be resistant to Evusheld, an antibody cocktail that is given to immunocompromised patients to prevent them from getting very sick if they contract COVID-19. The warning also said physicians can no longer rely on bebtelovimab, another monoclonal antibody therapy, for treatment.
For patients with weak immune systems — such as those who are older, have a disease like cancer or have had an organ transplant — it will be more important for them to avoid being infected, Atmar said. They should get the new bivalent COVID-19 vaccine booster if they haven’t done so already. They should also consider wearing a mask again while they’re out in public and avoiding large crowds, he said.
“For that group of patients, it will be much more important for them to take other measures to try to prevent getting infected,” Atmar said.
It’s too early to tell whether BQ.1 and BQ.1.1 will lead to a rise in infections or hospitalizations in the Houston area, so Ostrosky recommended that everyone should consider some basic precautions, regardless of whether they have a weakened immune system. That includes getting the bivalent booster shot and what he calls “strategic masking” — wearing a mask on a plane or in crowded areas. He also recommends staying home if you feel sick to prevent spreading an infection to others.
“We just had Halloween, and now it’s Thanksgiving, then Christmas break,” he said. “The last thing we want is to end up in a situation like we had last December and January, where we saw the biggest peak of all, for the number of cases.”