Health officials are closely monitoring new subvariants of Omicron—BA.4.6, BQ.1 and BQ.1.1. New variants and subvariants of the COVID-19 virus emerge regularly, and changes in their genetic codes sometimes make them more contagious.
Here are a few things to know about the new subvariants:
- The subvariants are spreading, but not quickly. The new subvariants are not spreading at the rate of the original Omicron strain, which overtook Delta in a matter of weeks in late 2021.
According to OHA’s variant monitoring data, BA.4.6 represented about 7% of samples sequenced in Oregon during the week of Oct. 9. A week later, that percentage was up to 10.3%. In that same time, the prevalence of the BQ.1.1 subvariant rose from about 2% of samples to about 3.5%.
Nationally, BA.4.6 represented about 9.3% of samples the week of Oct. 15 and dropped to 5.5% about a month later. In that same time, BQ.1.1 prevalence rose from 2.9% to 24.1% of samples.
“Even without direct data on vaccine effectiveness, the fact that these new subvariants are spreading means they’re evading immunity a little more than BA.4 and BA.5,” said Paul Cieslak, Oregon Health Authority (OHA) senior health advisor and medical director for Communicable Diseases and Immunizations. - It’s not clear whether these new subvariants will significantly evade immunity or cause more serious disease. Both BQ subvariants are offshoots of BA.5, and BA.4.6 evolved from BA.4. Virus mutations are normal and expected, but we don’t yet know whether these new subvariants will cause more or worse disease.
“In laboratory studies, it looks like BA.4.6 may evade some of our antibody responses to some degree,” Cieslak said. “But tests in a laboratory can’t perfectly replicate what might happen in the body.” - The current vaccines should still work to prevent severe disease, hospitalization and death. “The bivalent COVID-19 boosters, which were created to protect from BA.4 and BA.5, should still help protect against these new subvariants,” Cieslak said. This is because the new subvariants are offshoots of BA.4 and BA.5, with small changes to the genetic code for the virus’s spike protein.
So far, the vaccines have been effective at helping prevent severe illness from all the variants and subvariants that evolved from the original COVID-19 strain, and public health officials don’t expect that to change. But more real-world data are needed to be certain. - Evusheld, a preventative drug designed to give immunocompromised people extra protection on top of (or instead of) the vaccines, does not defend against the new subvariants as well as it does for previous strains.
“Evusheld is a cocktail of two antibodies that were designed to attack the ancestral strain of the COVID-19 virus,” Cieslak said. Unfortunately, this means that the drug does not work as well against the newer strains.
Patients receiving Evusheld should have a treatment plan in place and quickly seek medical attention if COVID-19 symptoms occur.
For the best protection, immunocompromised people who can receive COVID-19 vaccines should stay up to date with them. If it’s been more than two months since receiving a monovalent booster or completing a primary series, everyone age 5 and up can get the bivalent booster.
Public health officials are constantly monitoring COVID-19 variants through sequencing positive COVID-19 tests and wastewater testing, both at the state level and nationally. If these new subvariants prove to be much more contagious or start to significantly evade immunity from vaccines or prior infections, public health officials will know it relatively quickly.
Until then, getting vaccinated and staying up to date with the updated booster, as well as taking precautions like testing before attending crowded events and wearing masks in crowded indoor spaces will help slow the spread of COVID-19 and help you protect yourself and your loved ones.