You have valid points. I'm just highlighting an obvious and anecdotally observed pattern. Our eldest had the day off on school vax day. Shortly afterwards it seemed all kids got unwell with fever and cough for at least a week. Nationwide reports of flu spikes since. I've subsequently had similar symptoms for the last 10 days. The new Flumist nasal vaccine they were using is a LAIV (Live Attenuated Influenza Virus).

Correlation of the recent flu spikes with mass child flu vaccine is not proven or disproven. Nonetheless, certainly doesn't seem like an effective vaccine at reducing relevant current strains.