Table 1. Physical Characterization of Head-only RSV F Immunogens.

Construct	Oligomeric Statea	Yieldb (mg/L)	Antibody affinity KD (nM)			Physical Stabilityc
						Temperature (°C)			pH		Osmolarity (mM)		Freeze-thaw
			D25	AM22	Motad	50	70	90	3.5	10	10	3000
DS-Cav1e	Trimer	1.9	0.15	<0.01	0.04	0.9	0.0	ND	0.8	0.9	1.0	0.8	0.7
i-273	Monomer	0.3	33.3	13.6	1360	1.0	1.1	1.3	1.0	1.0	0.8	0.9	1.1
i-693f	Dimer	0.5	9.9	20.3	6.5	0.8	1.2	0.1	0.8	0.8	1.4	1.4	0.6
i-210	Trimer	5.5	0.7	4.2	761	0.9	1.0	0.2	0.9	0.9	1.3	1.2	0.1
i-447	Trimer	3.6	0.7	1.2	0.5	1.0	1.0	0.1	1.0	1.0	1.0	0.5	0.5

^a Assessed by gel filtration.

^b Yield following gel filtration.

^c Fractional D25 reactivity after 60 minutes at specified conditions or 10 cycles of freeze-thaw.

^d Mota, motavizumab.

^e Values from reference [16].

^f Maximum initial fractional D25 reactivity is reported for physical stability.

ND, not determined.