It appears to be a leaky vaccine. It is AED. All over the world except US media it is reported that it is the vaccinated getting sick.
Here is an article from the nih.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4516275/
which talks about this
https://www.pbs.org/newshour/science/tthis-chicken-vaccine-makes-virus-dangerous
thanks