You're correct. Basically what happens is your body still gets primed for some type of flu and produces antibodies. The predominant circulating strain H3N2 is

You're correct. Basically what happens is your body still gets primed for some type of flu and produces antibodies. The predominant circulating strain H3N2 is genetically a bit different than the vaccine strain of H3N2. So even though you don't have exactly the right antibodies, you still have some that can recognize the circulating strain and can start the response a bit earlier than someone with no antibodies.