Table 1.

Molecular analysis of the A/Taiwan/1/2021(H1N2)v virus

Determination of viral characteristics
Protein	Position	Mutations		A/Taiwan/1/2021	Function
PB2	627	E	K	E	Replication ability [26]
	701	D	N	D	Nuclear Import [26]
PB1	99	H	Y	H	Increased transmission in ferret [27]
PA	336	L	M	M	Increased polymerase activity in mice [28]
HA (H3 numbering)	Cleavage site	Single basic aa	Multiple basic aa	PSIQSR/GLF	high pathogenesis in poultry [29]
	190	E	D	D	Increased binding to human-type influenza receptor [30, 31]
	225	G	D	D	Increased binding to human-type influenza receptor [30, 31]
	226	Q	L	Q	Increased binding to human-type influenza receptor [30, 32]
	228	G	S	G	Increased binding to human-type influenza receptor [30, 32, 33]
NA (N2 numbering)	119	E	V	E	Resistance to oseltamivir and zanamivir [34]
	222	I	L	I	Resistance to oseltamivir and zanamivir [35]
	224	R	K	R	Resistance to oseltamivir and zanamivir [36]
	292	R	K	R	Resistance to oseltamivir and zanamivir [34]
M2	31	S	N	N	Amantadine resistance [37]
NS1	42	P	S	A	Increased pathogenesis in mice [38]
	92	D	E	D	Altered virulence in mice [39]
	205	N	S	N	Altered antiviral response in host [40]