A new and improved coronavirus vaccine is now available. The shots have been tweaked to target the latest subvariants of omicron that triggered the latest waves of infection, and preliminary data from Pfizer and Moderna suggests the new shots provide much stronger protection against infection than the current vaccines.
In late August, The Food and Drug Administration authorized the updated shots from both manufacturers. On September 1, the Centers for Disease Control and Prevention green lit the shots for distribution to the public.
Here’s what we know about the updated vaccines so far:
How is this shot different from the previous one?
The updated shot is a bivalent shot, meaning unlike the original COVID-19 vaccines that only targeted the strain that started circulating in 2020, the new shots contain two components: a piece that will go after the omicron subvariants (including BA.5 and BA.5) and a second piece that will target the original strain.
William Schaffner, medical director at the National Foundation for Infectious Diseases and NFID liaison to the CDC’s advisory committee, said this strategy is somewhat similar to what we do with the influenza vaccine, which is updated annually to match the circulating strains. Though it’s unknown just how often we’ll have to update our COVID vaccines, Schaffner expects they’ll need to be revamped every now and then to better match what’s going around.
Why didn’t it go through as many clinical trials?
The updated vaccine didn’t have to go through as many rigorous clinical trials as the shot we’ve been using, but this isn’t cause for concern.
“They don’t need as much data as the original vaccines since both shots include the original vaccine, utilize the same technology and platform, and are therefore expected to have similar safety profiles,” Venkatesh said.
Scientists evaluated the efficacy of the new COVID-19 shots by vaccinating a group of volunteers and measuring the antibody levels in their blood.
“In the laboratory, it shows these antibodies — which were created by this updated vaccine — actually work against those variants,” Schaffner said. The Food and Drug Administration and the CDC will refer to this data to guide their decisions on when and how to authorize the updated vaccines.
Schaffner again likened this approach to the flu vaccine. “When we update our annual influenza vaccine, we do not do clinical trials,” Schaffner said. By now, we’ve had enough experience with the flu shot that scientists can safely change the components each year so the shots can be swiftly manufactured and distributed.
Should you get the updated shot if you just had COVID?
“Waiting a bit of time is probably better, but there is no absolute interval,” Schaffner said, adding that several clinicians recommend waiting anywhere from weeks to a couple of months.
If you’re unsure about when to get the updated vaccine when the time comes, talk to your health care provider, who can provide more tailored recommendations based on your medical history.
“The anticipation is that we will be able to be protected through the winter season, at the very least.”
Should you mix and match the brand of shots?
Though some data has suggested that mixing and matching your COVID-19 shots may lead to a stronger immune response, this strategy has not been officially recommended.
Schaffner suspects mixing and matching will again be permitted, though not explicitly recommended. As of now, there aren’t any studies looking at the benefits of mixing vaccine brands for this updated shot, but that data will likely be available in the coming months.
That said, based on the data collected on the original shots, doctors don’t expect mixing shots to be an issue.
“We do know that mixing and matching is not harmful, and so if only one is available to you, you shouldn’t worry about that,” Venkatesh said.
Can you get the updated shot if you recently got a booster?
The official recommendation is that adults can get a bivalent shot at least two months after their last shot, whether that was a primary shot or a booster dose.
If your personal level of immunity may be low or if cases are high in your community, you should probably get it sooner rather than later, Venkatesh said. “Unfortunately, like the stock market, timing your COVID-19 shot is almost always a shot in the dark,” Venkatesh said.
How long will the bivalent shot provide protection?
It’s too soon to know for sure. Durability of the shots has changed with each variant, as new mutations have allowed the virus to bypass some of the immunity achieved through vaccination. In addition, the strength of the shots varies from person to person, depending on how robust of an immune response their body mounts after vaccination, according to Venkatesh.
The shots are much more long-lasting when it comes to preventing severe outcomes and keeping you out of the hospital. Seeing as antibody levels, which protect against infection, start to wane a few months after the current shots, it’s reasonable to expect the same may occur with the new shots.
“The anticipation is that we will be able to be protected through the winter season, at the very least,” Schaffner said.
Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.