Efficacy of a Recombinant Turkey Herpesvirus AI (H5) Vaccine in Preventing Transmission of Heterologous Highly Pathogenic H5N8 Clade 2.3.4.4b Challenge Virus in Commercial Broilers and Layer Pullets

Table 1

Summary of the two transmission experiments set up.

Type of chickens	Group	Vaccination	Subgroup	Challenge	Abbreviation
Broiler chickens	Group 1	rHVT-H5 vaccine at hatch, s.c.	Vaccinated challenged	Direct challenge at 5 weeks of age	G1- VCh
			Vaccinated contact	Physical contact from 8 h postchallenge	G1- VC
	Group 2	No	Susceptible challenged	Direct challenge at 5 weeks of age	G2- SCh
			Susceptible contact	Physical contact from 8 h postchallenge	G2- SC
Layer chickens	Group 3	rHVT-H5 vaccine at hatch, s.c.	Vaccinated challenged	Direct challenge at 7 weeks of age	G3- VCh
			Vaccinated contact	Physical contact from 8 h postchallenge	G3-VC
	Group 4	No	Susceptible challenged	Direct challenge at 7 weeks of age	G4-SCh
			Susceptible contact	Physical contact from 8 h postchallenge	G4- SC