No spreading of the vaccine strain of Nobilis SG9R

Two investigations were carried out to determine if the vaccine strain in Nobilis SG 9R could be spread by chickens after vaccination.

1. Vaccination of part of the rearing flock.
   Investigation of non-vaccinated birds in same house or nearest house on same farm.
   
2. Placing a vaccinated flock on a non-vaccinated laying farm.
   Investigation at regular intervals by bacteriological and serological examination.

Results and Conclusion
No indication of spread of the vaccine strain.