I did speak with a researcher over at Guelph today that deals specifically with poultry, and from what I was told:
Cull those that are obviously showing extreme signs.
Chicks that recover from milder symptoms may very well die later due to damage done by the virus.
Chicks that are unaffected...
For those asking about the vaccine
Avian Encephalomyelitis-Fowl Pox Vaccine, Live Virus AE Pox Vac 800VV/A5.0/S6.2 10M1.10 Fort Dodge Animal Health - USA
Avian Encephalomyelitis Vaccine, Live Virus AE Vac 800VV/A1.1/S6.2 1051.11 Fort Dodge Animal Health - USA
Nature of the disease
Avian encephalomyelitis (AE) is a viral disease of young chickens caused by a virus from the Hepatovirus family and characterised by central nervous system signs (Epidemic Tremors). It can be the cause of significant economic loss.
Classification
FAO List C disease...