Omicron BA.2 subvariant now accounts for a quarter of all new COVID cases in US

Stealth omicron
Posted at 3:58 PM, Mar 16, 2022
and last updated 2022-03-16 18:50:37-04

(WXYZ) — Cases of omicron's "stealth" subvariant are increasing. The CDC says BA.2 now accounts for roughly a quarter of new COVID-19 cases in the US.

We all saw how quickly omicron overtook the delta variant. When initial cases were sequenced, Americans were infected with either the original omicron variant or a sub-lineage called BA.1. Then in early December, we learned of another omicron sub-lineage BA.2. It was dubbed the "stealth" variant because it was harder to identify in lab-based PCR tests and could be mistaken as the delta variant.

Now while BA.2 did not take off like BA.1, it has been gaining ground. It currently makes up almost a quarter of all new cases - 23.1%, to be precise. And it's very prevalent in the Northeast. Between New York and New Jersey, roughly 39% of new cases are BA.2. And in New England, 38.6% are BA.2.

Could it become the dominant strain in the US? Anything is possible. We've seen it happen in other countries like the United Kingdom. Unfortunately, cases there are up roughly 52% over the last week.

Having said that, when you look at US data, the doubling of numbers for BA.2 appears to be slowing down. And while BA.2 is taking up a more significant portion of cases, the CDC has been tracking fewer infections overall. So at the moment, it appears like BA.2 infections are spreading faster.

BA.2 does not appear to be more severe than BA.1. It's about the same risk. That's based on preliminary research from South Africa and the United Kingdom. And when looking at US data, hospitalizations and deaths have continued to drop or plateau even though BA.2 is more prevalent now.

And there's more good news, other research has found BA.2 is unlikely to cause reinfections in people who were infected with BA.1. And BA.2 doesn't appear to evade vaccine protection as easily as BA.1.

However, when it comes to transmissibility, BA.2 is roughly 30% more contagious than omicron. So while our numbers are still looking good here in the US, we need to be mindful that the virus is not going away. And it has the ability to spread quickly. Once again, I remind everyone that the best way to stay safe is to be fully vaccinated and boosted.

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