Table 1.

Neutralizing antibody titers against the autologous virus.

	Hours	Patient ID
		D1-14	D2-44	D2-57	D3-46	D4-12	D4-49
Period after fever onset	24	–	–	1:73	–	–	–
	39	–	–	1:150	–	–	–
	63	–	–	1:331	–	–	–
	72	1:70a	1:234	–	–	1:188	1:38
	84	–	1:1912	–	–	–	–
	85	1:62	–	–	–	–	–
	86	–	–	–	–	1:260	–
	87	–	–	1:2867	–	–	–
	89	–	–	–	–	–	1:104
	96	–	–	–	1:25,553	–	–
	98	–	–	–	–	1:1173	–
	108	–	1:1213	–	–	–	–
	113	–	–	–	–	–	1:417
	115	–	–	–	1:46,414	–	–
	132	–	1:3500	–	–	–	–
	137	–	–	–	–	–	1:2952
Infection history		Primary	Secondary	Secondary	Secondary	Secondary	Secondary

^aNeutralizing antibody titer was expressed as the maximum serum dilution showing > 75% focus reduction (FRNT75).