BA.5 Variant: How Much Do Vaccines, Previous Infection Protect You?
A new omicron subvariant is now the dominant coronavirus strain in the U.S. And, while it's still early, experts are warning that the BA.5 variant may be the most contagious variant yet thanks to its ability to evade the immune protection many of us already have.
The BA.5 variant is now responsible for an estimated 65% of COVID-19 cases in the country, according to the most recent data from the Centers for Disease Control and Prevention. Meanwhile, the BA.2.12.1 variant, which caused the vast majority of cases just a month ago, now only accounts for about 17% of cases.
So, are we still protected from infection with BA.5 and its sibling BA.4? The answer "depends on a whole host of factors," Dr. Scott Roberts, assistant professor and infectious disease specialist at the Yale School of Medicine, told TODAY.
The biggest factor, he said, is the emergence of these new omicron subvariants (BA.4 and BA.5), "which appear to have a have pretty substantial immune evasion — not just from the COVID vaccine series, but even from people who got infected with the initial omicron around the holidays."
It also matters how long it's been since your last dose or your last infection, as well as your individual health status, Dr. Kawsar Talaat, an associate professor at the Johns Hopkins School of Public Health who studies vaccines, told TODAY.
While we don't have a ton of data right now about our protection against BA.5, early research suggests this variant is especially concerning.
How protected am I right now?
Generally, your protection from infection peaks about two to four weeks after you get a vaccine dose, Roberts explained. "That's still, to this day, when we see the highest antibodies in the blood ... and then it kind of wanes from there."
Throughout the pandemic, experts have estimated that protection against reinfection lasts at least two to three months, he said. In fact, protection from previous COVID-19 infections can last up to a year depending on your immune system, Dr. Kristin Englund, an infectious disease specialist at the Cleveland Clinic, told TODAY.
The CDC's guidance operates under the assumption that most people have protection for at least about 90 days after infection. "That still holds up relatively well," Roberts said, but cautioned that we don't have good data yet on how that protection fares against the new BA.5 variant.
It's particularly challenging to predict how well our current protection stacks up against new variants because the strains are turning over so quickly, Talaat said. "For example, I had COVID two weeks ago and I probably didn't have what the dominant strain is now," she said. "It's really hard to predict (how long protection lasts) because this virus changes so fast."
What if I'm fully vaccinated?
If you've only gotten your primary series, you should get your booster. "We know that, for omicron, two doses are not nearly as good as three," Talaat said. But even with a third dose, the new variants can be an issue.
Early data published last week in the journal Cell suggest that BA.4 and BA.5 evade protection more than previous variants even in people who have had three vaccine doses.
But it's still important to get your booster if you haven't yet, Englund said. "I would not put off getting your first booster. It may not fully protect you against getting infected, but it's still likely to protect you against severe infection," she explained.
What if I got my second booster?
Some of the best data we have so far on how well booster protection holds up now comes from a May study in the New England Journal of Medicine, Roberts noted.
The researchers found that, among people 60 years and older in Israel who received a second booster, protection against infection with the original omicron peaked after four weeks and fully waned after just eight weeks. However, protection against severe disease and death stayed strong.
Right now, only older adults and immunocompromised people are eligible to get a second booster. But the Biden administration is considering a plan that would open up eligibility to all adults who want another shot. The move would allow caregivers, people who frequently interact with older adults and new parents, for example, to better safeguard their communities.
"What if I live with somebody who's immunocompromised and I just want to make sure that I'm affording my relative the very best protection?" Englund emphasized. "Why not do the best that you can just to help boost your immune system so that you're less likely to carry the virus and pass it on to somebody else?"
What if I just had COVID-19?
Unlike with earlier variants, a previous infection isn't much of a guarantee of protection from BA.5. "So even if you just got infected in the last three months, you may potentially get infected with BA.5," Camins said, adding that he knows of people who got reinfected within four weeks when omicron came on the scene.
Even people who are vaccinated and have a recent previous COVID-19 infection have less protection against BA.4 and BA.5 than they did against previous variants, research shows.
In a study published online last month in Nature, researchers found that BA.4 and BA.5 were better able to evade protection from three doses of vaccine than BA.2. The new variants were also better able to evade protection in vaccinated people who had also had an omicron infection, a finding the authors described as "striking." Other studies, which have not yet been peer-reviewed, showed similar findings.
Still, the experts agreed that reinfection in fewer than three months is likely to remain rare — even with BA.5 in the mix.
Vaccines still provide solid protection against severe disease and death.
All of the experts TODAY spoke to emphasized that, while protection against infection may be waning, the vaccines still protect against severe disease, hospitalization and death. COVID hospitalizations in the U.S. have doubled since May, but this is likely because of the sheer number of people who've been infected with BA.5 and BA.4 recently, NBC News reported. The strains do not appear to cause more severe illness, and the vaccine still reduces risk of severe complications overall.
People who've had COVID-19 should still get vaccinated, Englund said, because research has shown that this type of "hybrid immunity" actually provides better protection.
"What's important is our best protection against hospitalization and severe disease remains being vaccinated," Talaat said. "And that getting infected can boost that protection even further."
Remember, your risk is not all or nothing.
It's tempting to think of activities as safe or unsafe, but your risk for COVID-19 is never all or nothing, Talaat said.
Instead, your protection peaks a few weeks after a vaccine dose or infection and then gradually wanes after that. So it's safest to continue using the public health tools we know work, such as:
Wear a mask. One-way masking still works, Camins said, but you should opt for a higher-quality mask if you can, like an N95 or KN95 respirator.
Do things outside when you can, Talaat advised. With better airflow, it's less likely for the virus to spread in outdoor environments than indoors.
If you have risk factors that make you more likely to develop severe COVID-19, chat with your doctor before you get sick. Ask them about treatment options, like Paxlovid, so you have a plan in place to get medications before you need them, Camins suggested.
Stay aware of what's going on in your community. "I understand that people are tired of it," Camins said. But it's important to stay aware of the COVID-19 situation around you, including new variants, like BA.5.
Get up to date on vaccines if you aren't already. And look forward to an omicron booster in the fall.
Finally, remember, recommendations may change as the dynamics of the pandemic continue to evolve. "We've learned so much from this virus," Talaat said. "The thing that I've learned is that it's almost impossible to predict anything — except that things will change."
Englund agreed: "You know, don't get too used to BA.5," she said. "There's something else around the corner."
