TABLE 3.

Endpoint titers of sera from rabbits immunized at low and high doses of glycoproteins as determined by gp120 ELISA^a

Immunogen	Inoculation
	Low dose		High dose
	Animal	Endpoint titer (3rd)	Animal	Endpoint titer
				2nd	3rd	4th
WT monomer	A1	+++++	3	+++++	+++++	++++
	A2	++++	4	+++	++++	+++++
	A3	++++	5	++++	+++++	++++
			6	+++++	++++	+++++
WT trimer	B1	++++	7	+++++	+++++	++++
	B2	++++	8	NDb	+++++	+++++
	B3	++++	9	+++++	++++	++++
			10	+++++	+++++	++++
Stabilized trimer	C1	++++	11	+++++	++++	+++++
	C2	++++	12	+++++	+++++	+++++
	C3	++++	13	+++++	+++++	+++++
			14	++++	+++	++++
			15	+++++	++++	+++
			16	+++++	+++++	+++++
			17	+++++	+++++	++++

^aEndpoint ELISA titers are defined as the last reciprocal serum dilution at which the optical density signal was greater than twofold over the signal detected with the preimmune sera. Symbols for the endpoint titers are as follows: +++, 2.5 × 10⁴; ++++, 1.25 × 10⁵; +++++, 6.25 × 10⁵.

^bND, not determined.