Doctors say it’s too soon to know whether the Omicron variant of COVID-19 is reason to worry.

The Delta variant muscled out other COVID strains over the summer. In Indiana, it’s accounted for 96-percent of COVID infections this month, while the original strain and the Alpha, Beta and Gamma strains have disappeared entirely. But in South Africa, where scientists first sequenced Omicron, it’s been able to outcompete Delta. Nir Menachemi, health policy and management chair of I-U’s Fairbanks School of Public Health, says the fact Omicron is able to crack Delta’s dominance “raises an eyebrow.”

But that’s not the same as saying it’s more dangerous. Some other variants which appeared fearsome at first have turned out not to be. Menachemi says it’s not clear yet whether Omicron is more easily transmitted, nor whether the illnesses it causes are more severe. He says it’s likely to take three or four weeks to get those answers.

Menachemi says it’s also unknown how well the COVID vaccine will protect against Omicron, but says he’s optimistic it will. He notes the vaccine has been effective against all the previous variants. And he points out the countries where Omicron has surfaced so far are among the world’s least vaccinated.

Menachemi says low vaccination rates are what give the virus the opportunity to mutate. The more unvaccinated people there are, the more potential hosts there are, and the more human laboratories for the virus to change.