Table 2.

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

InoculumaNo. of inoculationsNTb to influenza A/WSN virus at:% Survivalc after challenge
Initial bleedSecond bleed
VSVrwt2<1:8<1:860d
VSV-HA21:6401:2,560100
VSV-HA11:640NBe 100
  • a Each inoculum contained 5 × 104 PFU/mouse.

  • b NT, 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.

  • d Surviving mice showed signs of pathogenesis, i.e., average body weight loss of 25%.

  • e NB, 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.