Buzz
If you recently contracted COVID, it's likely that you encountered BA.5, the dominant strain in the U.S. right now. While this new version of COVID is worrisome, it's not dramatically different from earlier variants. Here's what you should know.
Where did BA.5 originate?
BA.5 isn't a completely new variant. It's actually a branch of the Omicron family. As a refresher, we first saw the original SARS-CoV-2, followed by Alpha in late 2020, Delta hit hard in summer and fall 2021, and then Omicron appeared toward the end of 2021. (You can track each variant's rise by looking at COVID hospitalization charts over time.)
The first Omicron strain was BA.1, which was soon followed by BA.2 in the U.S. While BA.2 is on the decline, BA.5 (along with its close relative, BA.4) is becoming more prevalent. These two variants are so alike that public health officials often group them together as 'BA.4/5.'
Are vaccines now outdated?
No. Your immunity—whether from a vaccine or prior infection—is still valuable. This idea that immunity is ineffective needs to be put to rest. However, BA.5 differs enough from previous variants that your immunity won’t provide perfect defense.
The vaccines available today still contain the same formula they had when first approved, which was based on the original COVID strain. Since then, the virus has evolved significantly. Newly reformulated vaccines are expected to be available this fall, and they should offer more protection against BA.5 than the current ones do.
That said, those who received the original vaccines are still well protected from severe illness. If you were vaccinated and experienced a mild case of COVID, your vaccination likely kept it that way. For example, this study on B.1 Omicron found that unvaccinated individuals were 23 times more likely to end up in the hospital compared to those who had been vaccinated and boosted.
Is reinfection inevitable for everyone?
You may have heard that it’s now possible to get reinfected with BA.5 every few weeks. This, however, is a misunderstanding. Omicron is distinct enough from Delta that it’s possible to first get Delta, then a few weeks later, contract Omicron. But that does not mean you can continuously get Omicron.
We have no evidence to support that idea. In fact, most of the individuals contracting BA.5 are those who had never previously had COVID. Reinfections may seem like a new development, but this is partly because there were far fewer infections in the initial years of the pandemic. The percentage of people who have recovered from COVID surged from 30% to 60% this past winter. As science journalist Ed Yong notes, 'We’re hearing more about reinfections now in part because the number of people who could possibly be reinfected has doubled.'
So yes, the virus can evade some of our defenses (from vaccines or previous infections). It's still crucial to avoid infection, even if we've had it before, and those updated vaccines will be a welcome development when they arrive. But ultimately, it’s the same virus—just a different variant.
