It doesn't seem to go away easily from a cold.

The cold I caught last week still hasn't gone away.

I also received the flu vaccination.

Why am I not getting better? I've already caught a cold twice this year.

I will make sure to carefully check the next flu vaccination. I think the flu vaccination I received a while ago might not have been very effective. This is the first year I’ve caught a cold so often even after getting the flu shot.