How Bad Is the BA.5 COVID Variant, Really?

If you got COVID recently, chances are good that it was BA.5. This new version of COVID is concerning, even though it’s not that different from the ones that came before it. Here’s what you need to know.

Where did BA.5 come from?

It’s actually not a whole new variant. BA.5 is a branch of the Omicron family tree. If you’ll recall, we first had original flavour SARS-Cov-2, then we had Alpha around Thanksgiving 2020, then we got hammered by Delta in summer and fall 2021, and then Omicron came along late in 2021. (You can see each variant’s peak clearly if you look at a chart of COVID hospitalizations over time.)

The original Omicron strain was BA.1. It was then followed in the U.S. by BA.2. Now, BA.2 is declining while BA.5 (and its close cousin, BA.4) are on the rise. BA.4 and BA.5 are so similar to each other that you’ll often see public health officials refer to them together as “BA.4/5.”

Are vaccines obsolete?

No. Your immunity (from a vaccine or from a previous infection) is not useless. People need to stop saying this. That said, BA.5 is different enough from previous strains that your immunity isn’t going to give you perfect protection.

The vaccines that are currently on the market still have the same formulation as when they were first authorised. In other words, they were based on original-flavour COVID. The virus has mutated a good bit since then. Reformulated shots should be available this fall, and those are expected to provide more protection against BA.5 than the current vaccines.

Even so, people who got the old vaccines are still pretty well protected against severe illness. If you were vaccinated and got a mild case of COVID, it’s very likely that your vaccination status is what kept it mild. For example, this study on B.1 Omicron found that people who were unvaccinated were 23 times more likely to end up in the hospital than people who were vaccinated and boosted.

Are we all going to get reinfected?

You may also have heard that it’s now possible to be reinfected with BA.5 every couple of weeks. This is also based on a misunderstanding. Omicron is different enough from Delta that you can get Delta and then, just a few weeks later, get Omicron. But that is not the same as saying that you can get Omicron over and over.

We don’t have any evidence suggesting that is the case. In fact, most people who are getting BA.5 infections are people who had not previously had COVID. Reinfections may feel like a new phenomenon, but that’s in part because there just weren’t that many people infected in the first year or two of the pandemic. The percentage of people who had recovered from COVID jumped from 30% to 60% this past winter. As science journalist Ed Yong points out, “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 protections (from vaccines and from prior infections). It’s important to still try to avoid getting infected, even if we have been infected before, and those updated vaccines will be very welcome when they arrive. But the bottom line is that it’s the same old virus, just a different flavour.