Influenza cases have stayed steady in Maine this winter, in contrast to surges seen in the South and much of the East Coast.

Flu cases peaked at “high” or “very high” levels at the end of December or the first week of January in states such as New York, New Jersey, Massachusetts, Georgia, Virginia and North Carolina, the U.S. Centers for Disease Control and Prevention said.

Influenza cases in Maine nearly doubled during the week ending Dec. 23, from 260 to 510 cases. But instead of seeing exponential growth since then, Maine’s cases have ranged from 500 to 600 cases per week through mid-January. In the week ending Jan. 26, the most recent data available, the Maine CDC reported 673 cases.

Influenza is unpredictable, public health experts say, and even though Maine has largely been spared from a bad flu season so far, cases could spike later this winter or spring. Flu season lasts from October through May. The predominant strain circulating in Maine is influenza A H1N1.

Symptoms of influenza include fever, aching muscles and joints, headache, chills, cough and sore throat.

It’s not too late to get vaccinated and vaccines are still available at primary care physicians and many pharmacies.