Table 2.

 The cross‐reactivity of the post‐vaccination HI antibody response in ferrets to influenza A H7 strains

Ferret	Virus strain
	RD‐3	A/mallard/ Netherlands/ 12/2000 (H7N7)	A/New York/ 107/03 (H7N2)
Vaccinated	76	8	11
Control	–*	–*	–*

Groups of four ferrets were vaccinated with two doses of 24 μg HA aluminium adjuvanted H7N1 vaccine or saline (controls) and blood collected 18 days post‐vaccination. Serum HI titres 8 days after the second vaccination were measured by a modified HI assay using cell grown RD‐3 (H7N1) or egg grown A/mallard/Netherlands/12/2000 (H7N3) and A/New York/107/03 (H7N2) viruses and horse red blood cells. The geometric mean titre (GMT) of each strain is given for the vaccinated and control groups. The limit of detection of the HI assay was 8 and HI antibodies were detected in all immunised ferrets to all strains.

*Negative HI titres (<8).