Table 3. Agglutination of turkey erythrocytes by recombinant viruses with chimeric and mutant NA genes in the presence or absence of oseltamivir.

Recombinant virus		Haemagglutination titre (HAU per 25 µl)
HA	NA	− Oseltamivir	+ Oseltamivir
A/NL/109/03	NA-1	64	64
A/NL/109/03	NA-2	32	32
A/NL/761/09	NA-1	Not rescued
A/NL/761/09	NA-2	32	<2
A/NL/761/09	A/NL/109/03	<2	<2
A/NL/761/09	A/NL/109/03–150HR	16	<2
A/NL/761/09	A/NL/109/03-194VI	<2	<2
A/NL/761/09	A/NL/109/03-215IV	<2	<2