Many replies thought the "amazing" adjective was about the fact that vaccines work at all. Methinks you are a bit knee-jerk against people you even suspect of opposing vaccines.

I thought it referred more to the logistics of getting hundreds of producers coordinated and hundreds of thousands of chickens vaccinated in so short a time. Actually, if they have the data, it would make for fascinating study about epidemiology in vaccinated populations. Some chickens were probably missed, but once the vaccination rate reaches some critical level, the disease doesn't spread the same way.

So, no need to assume the writer is one of the "crazies" and no need to have an OT comment thread about it.