It doesn’t seem to take long for symptoms of COVID’s latest variant, Omicron, to start showing up.

While it’s taken around four or five days for coughs, headaches, and fevers to manifest when infected with previous COVID strains, it looks as if the incubation time table for Omicron is even more abbreviated.

Data is still limited on COVID’s latest variant, which was first detected in Botswana and South Africa in mid-November, but a recent study in Norway indicates a median three-day window between exposure to the Omicron variant and symptoms—meaning that Omicron is able to spread more quickly.

That’s certainly playing out in the test results. A mere two weeks after the first Omicron case was identified at the beginning of this month, positive COVID cases are at their highest levels since late summer. There were 242,794 new reported cases in the U.S. on Wednesday, according to the New York Times COVID database. New cases are up more than 80% in New York over two weeks. And chains such as CVS and Walgreens are selling out of in-home tests as consumers scramble to detect the virus before holiday gatherings.

Cold-like symptoms

Omicron is still new, and the Center for Disease Control and Prevention says it is still working with partners to gather data on the variant’s characteristics. Early research conducted in London suggests that a runny nose, headache, fatigue, sneezing, and a sore throat are the most common symptoms.

It’s a good idea to stay on the lookout for the symptoms synonymous with earlier strains, which include the following, per the CDC:

Fever or chills

Cough

Shortness of breath or difficulty breathing

Muscle or body aches

New loss of taste or smell

Congestion

Nausea or vomiting

Diarrhea

People who are fully vaccinated can still be infected, and some studies indicate that vaccines aren’t as successful at preventing Omicron infection as they have been with previous variants. However, vaccines are still highly effective in preventing severe cases of COVID, and boosters help. Those who are unvaccinated, the elderly, or people with pre-existing conditions are still the most at risk.