While the SARS-CoV-2 virus currently causing most of the COVID-19 cases in the US is an Omicron subvariant, it also incorporates parts of the Delta variant, the Associated Press reports.
Because of this, the AP says that the subvariant — dubbed BA.2.12.1 — may not only spread faster than other Omicron subvariants but may also better escape immunity. It adds that BA.2.12.1 — linked to 58 percent of COVID-19 cases in the US last week — is not the only Omicron subvariant harboring bits of the Delta, as BA.4 and BA.5, which are circulating in South Africa, also harbor Delta-like changes.
The AP adds that this could have implications for who may be protected or at risk for the variants. It notes that a recent preprint posted to BioRxiv suggests that people previously infected with an Omicron variant may have limited protecting against reinfection with the new Delta-infused Omicron variants while those previously infected with Delta might have more protection. Study author Shan-Lu Liu from Ohio State tells it, though, that because protection wanes over time, people who had Delta a while ago may not see much added protection. He adds there that boosters do provide strong protection.