TABLE 2.

Neutralization titers and percent survival of mice challenged with influenza A/WSN virus

Inoculuma	No. of inoculations	NTb to influenza A/WSN virus at:		% Survivalc after challenge
		Initial bleed	Second bleed
VSVrwt	2	<1:8	<1:8	60d
VSV-HA	2	1:640	1:2,560	100
VSV-HA	1	1:640	NBe	100

^aEach inoculum contained 5 × 10⁴ PFU/mouse. 

^bNT, neutralizing antibody titer. For initial bleed, pooled sera were collected 3 days prior to boost. For second bleed, pooled sera were collected 3 days prior to challenge. 

^c% Survival indicates the percentage of mice surviving lethal challenge with influenza A/WSN virus. There were five mice in each of the three inoculum groups. 

^dSurviving mice showed signs of pathogenesis, i.e., average body weight loss of 25%. 

^eNB, no boost. Initial inoculation was done at day 0, sera for initial bleed were taken at day 18, and challenge with influenza A/WSN virus occurred at day 21.