Table 3. Stem MAb neutralization against A/Puerto Rico/8/1934 escape mutants.

	HA-pseudovirus neutralization titer (μg/ml)				Plaque reduction titer (μg/ml)
Mutants	4C2 (IgG1)	C179	CR6261	FI6	4C2 (IgG1)	C179	FI6
WT	0.6	0.31	0.09	0.11	12.8	27.7	3.7
K55E	3.42	2.02	0.43	0.53	35.2	25.7	2.4
V444L	3.01	1.73	0.38	0.49	29.2	68.8	7.1
K55E.V444L	4.53	2.81	0.42	0.54	63.2	91.2	5.9