On Wednesday, the Centers for Disease Control and Prevention (CDC) released early data on the effectiveness of the updated COVID-19 boosters and how they're faring against the most common omicron subvariants, known as XBB and XBB.1.5.
Fortunately – given that America is in the middle of the winter COVID season — the news is hopeful.
"All of a sudden, it binds to the host receptor better than most variants that we know so far."
In adults up to age 49, both boosters from Pfizer-BioNTech and Moderna were nearly 50 percent effective against symptomatic infections from both BA.5-related infections and XBB/XBB.1.5-related infections. However, for those 65 and older, effectiveness dropped to 37 percent against BA.5 and 43 percent against XBB/XBB.1.5.
The 37-to-50 percent range might not seem that high. But, in the grand scheme, these numbers are comparable to the standard range of flu vaccine effectiveness.
The report is based on COVID-19 test results of more than 29,100 adults with COVID symptoms who were tested at pharmacies nationwide between Dec. 1 through Jan. 13. As Salon previously reported, subvariant XBB.1.5 has been rapidly increasing in spread across the country and exhibiting disconcerting immune-evasive properties. Some hospitals have noted that they've seen a surge in cases, and some worry that the winter could be similar to last winter's COVID-19 outbreak. As of January 21, XBB.1.5 is responsible for about 1 in 2 new COVID-19 cases.
"XBB is a different ballgame," Dr. Rajendram Rajnarayanan, an assistant dean of research and associate professor at the New York Institute of Technology campus in Jonesboro, Arkansas, previously explained to Salon. "With a recombinant, you get mutations that makes it more evasive. And as we expected, [XBB.1.5] changed one small mutation, a V changed to a P at the 486 position. And that's it. All of a sudden, it binds to the host receptor better than most variants that we know so far."
Dr. Brendan Jackson, the head of the CDC's COVID response, said in a call with reporters this week that the CDC's data was "quite reassuring." "These updated vaccines are protecting people against the latest COVID-19 variants,"Jackson said.
Unfortunately, not many people have received the latest and greatest booster; only about 15 percent of Americans have received a bivalent booster, according to CDC data. As Dr. Jenna Clark, a Senior Behavioral Researcher at Duke University's Center for Advanced Hindsight, previously wrote for Salon, the lack of people getting their bivalent boosters isn't necessarily a consequence of vaccine hesitancy.
"The majority of people say the bivalent booster is as safe and effective as the original COVID-19 vaccine – if not more – and 70% of those already vaccinated against COVID-19 intend to get a booster in the next year," Clark explained. "But there's a big gap between intending to do something and actually getting around to it — and that is where the problem lies."
Experts hope the CDC's new data might motivate people to get these boosters.
"With this data, we see there is a benefit that might convince some people to sign up and get a bivalent booster," Dr. Peter Hotez, co-director of the Center for Vaccine Development at Texas Children's Hospital, told NBC News.
