(NEXSTAR) – If you’re stuck at home with COVID-19 right now, you’re far from alone. The United States is seeing another spike in coronavirus cases, driven by two new types of the omicron variant.
BA.4 and BA.5, both variants of the highly pathogenic omicron, make up more than 90% of the country’s new cases, according to tracking by the Centers for Disease Control and Prevention.
There are a few reasons why these two subvariables – particularly the dominant BA.5 – are spreading like wildfire and are having such a big impact in the US right now.
BA.4 and BA.5 are more sneaky
Early evidence suggests that BA.4 and BA.5 are no more infectious than the original omicron strain. However, they appear to be better at evading prior immunity.
This means that people who have some immunity – whether from vaccines or a previous COVID infection – are still susceptible to infection from BA.5.
Plus, it’s been over six months since our last major national surge of our first omicron variant. Those infected in that wave probably did have some boosted immunity, but that window has passed for most of us.
“The good news is that the vast majority of advanced infections now are outpatient diseases,” said Dean Bloomberg, chief of pediatric infectious diseases at UC Davis Hospital for Children. “It doesn’t lead to the kind of severe illness we saw earlier in the pandemic when no one had immunity, which led to increased hospitalizations and deaths.”
People are testing at home, anyway
While you may feel like you know more people who are getting COVID than ever before, the case rates tracked by public health departments don’t seem to reflect an exponential rise. The New York Times’ comprehensive COVID tracker shows a rise in new cases, but the latter curve is waning with the increase last winter.
Epidemiologists agree that cases of COVID-19 are currently largely uncountable.
“With home testing, we’ve lost our ability to trace reported cases,” said Dr. George Rutherford, an epidemiologist at the University of California, San Francisco.
When someone has the virus at home, this case is often not reported to public health officials, which leaves us with a vague idea of how common BA.5 is.
Moreover, milder symptoms mean that fewer people may test themselves. If they never test for the virus, they may still inadvertently spread it in the community.
Covid restrictions are gone
The original wave of coronavirus cases – before vaccinations were received – caused widespread restrictions, closures, and concealment requirements. The delta surge in the summer of 2021 and the original Omicron wave last winter led to more cautious sites and countries re-commissioning the mask. Now, there are virtually no restrictions on COVID-19 across the country.
With less hiding and more mixing, the virus can spread more quickly in the community.
The CDC recommends wearing a mask indoors if your county has a “high” level of COVID transmission. As of Tuesday, more than a third of US counties were in that category. You can check the status of your county on the CDC map.