There's something unusual in this year's flu season. Influenza A, the strain of the virus that's typically most common at this point in the year, is instead proving rare in the Rochester area, and influenza B, which often waits for later months to strike, is responsible for the vast majority of recent cases.
In Monroe County, influenza B comprises more than 80% of the confirmed cases this flu season.
In Ontario County, flu B is outpacing flu A by a 2-1 ratio.
But the public health directors in those counties said for most people, the distinction won't matter.
"It means nothing, other than there's a lot of flu out there," said Ontario County public health director Mary Beer.
She said the type of flu that's most prevalent does not change the messages she wants to get across to local residents.
"Get your flu shot. Wash your hands. Stay home if you're sick. Try not to go to work or to school so that you're not spreading it around," Beer said.
For researchers, however, the particular type of flu in circulation is of deep interest.
"It's most important for the people who develop the vaccines," said Emil Lesho, an infectious disease specialist at Rochester Regional Health. "They need to know specifically, exactly, what type of strains and substrains are out there so that they can optimize the most effective vaccine."
Each vaccine dose can only carry a small number -- usually three or four -- of vaccine strains to inoculate the recipient. That means vaccine developers need to guess at precisely which substrain of the virus will be most common.
Fortunately, Lesho said, "At least for the B types, this year's vaccine was pretty accurate."
Lesho said that's important because flu B is "through the roof here."
So could the flu season end early because Flu B is getting itself out of the way now?
Lesho said not to get your hopes up.
"No. I wouldn't -- I wouldn't make that assumption. That's not a good assumption to make. Nope."