The number of confirmed flu cases is on the rise, but we likely won’t see its peak until sometime early next year.

“It follows this normal pattern where it goes through Asia, down through Australia, up through South America, Central America to the United States and over to Europe. And you see that same progression year after year,” said Dr. Cara Christ with the Arizona Department of Health.

Christ said this pattern helps determine which flu strains are circulating, and which will ultimately be used in U.S. vaccines.