DENVER — More than two months into the campaign to get people to take updated COVID-19 boosters, only about 8% of people who are eligible have received the shot, though about 23% of those 65 and older have, according to Centers for Disease Control and Prevention estimates.
In Colorado, about 18% of Coloradans eligible for the shots, which target more recent variants, have gotten one, and more than 35% of people who are 65 or older have, according to the Colorado Department of Public Health and Environment.
Data on how well the boosters work are still coming in, and for now, the picture is mixed. Some studies found the updated shots are roughly the same as the original ones in terms of stimulating the immune system to produce antibodies against the BA.5 variant, which until recently was the predominant version of the virus nationwide. Others found they performed better.
It’s not yet clear how well the updated shots may work against newer variants like BQ.1, BQ.1.1 and BF.7. All are members of the omicron family.
The state health department urged people to get their booster by Thursday if they planned to gather on Thanksgiving because it takes about two weeks to achieve the highest level of protection.
COVID-19 and flu hospitalizations have increased over the last two weeks, though at this point they’re still at manageable levels. Children’s hospitals are reporting unprecedented numbers of patients sick with respiratory syncytial virus, which normally causes colds but can be severe in infants and toddlers.
“From more than a year of data now, we know that people who are current on their vaccines are much less likely to be hospitalized,” state epidemiologist Dr. Rachel Herlihy said in a news release. “Preventing hospitalizations is critically important now as we are also seeing increases in RSV and influenza.”
Here’s what we do and don’t know about the booster shots:
Question: How are these different from the original shots?
Answer: The shots people started receiving in late 2020 only introduced the spike protein — what the virus uses to enter cells — from the original version of the virus. The updated boosters teach the body to recognize two spike proteins: the one from the original strain of the virus, and the one on the BA.5 and BA.4 variants. Since the rest of the virus isn’t attached to the spike, vaccines essentially give the immune system a training round, without the possibility of getting sick or infecting others.
Ideally, the body will recognize the spike and antibodies will block it, preventing infection altogether. It’s been difficult to achieve that level of immunity against the omicron variants, including BA.5, but vaccination still gives the body a head start in recognizing the virus and heading off the worst outcomes, like hospitalization and death.
Q: Who can get these?
A: Anyone who is at least 5, has completed their primary vaccine series and hasn’t had a COVID-19 shot in the last two months is eligible. Some doctors recommend waiting a few months if you recently had the virus, to maximize your immune response.
People who’ve already received their initial shots can get the updated boosters from Pfizer or Moderna, regardless of whether they’re already had two shots, three, or more.
Novavax received permission in October to offer its original vaccine as a third shot, but not for boosters beyond that. Some experts hoped that people who didn’t trust the technology in the Pfizer and Moderna shots would opt for Novavax, but demand has been tepid.
Q: How well do the new shots work?
A: The overall picture suggests they offer some benefit, but aren’t a magic bullet.
Pfizer released data Thursday showing people who got the updated shots had higher antibody levels against the BA.4 and BA.5 variants than those who got another dose of the original vaccine. Three small studies haven’t found a meaningful increase in antibody levels compared to another dose of the original shot, while two others did see an advantage.
The ultimate test of the updated vaccines, though, will be whether people who had them are less likely to get sick, be hospitalized, or die. It will take longer to find that answer because a significant number of people who got the shots need to be exposed to the virus first.
Q: Will this be my last shot for a while?
A: Maybe. The White House has certainly pushed the idea of transitioning COVID-19 vaccines to an annual schedule, alongside flu shots. Peter Marks, head of the U.S. Food and Drug Administration’s vaccine division, told STAT News said higher-risk people will need more than annual boosters because the virus is mutating so quickly and immunity starts to wane in less than a year.
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