Here is how well the flu vaccine is working this year.

Influenza A(H1N1) and A(H3N2) are basically circulating in equal proportions so far. There isn't much influenza B circulating.

The A(H1N1) vaccine strains are an excellent match to circulating H1N1 viruses.

The A(H3N2) vaccine strains are okay matches this year, but some of the J.2 subclade have reduced susceptibility to the vaccine. Unfortunately most of the H3N2 circulating is J.2. The vaccine strains are from the J subclade.

So the flu vaccine should be fairly decent this year depending on how much H3N2 and what subclade circulates.

H3N2 typically is a more severe flu virus. We are on track for a fairly typical pre-pandemic flu season this year.

Make sure you get vaccinated. Even an imperfect match still reduces the risk of severe flu.