Table 2.

Survival of mice infected with chimeric virusesa

Virus dose (PFU/mouse)Wuh95/PR8Wuh95+3/PR8
No. of survivors/total no. of miceSurvival (%)Mean no. of days to death ± SDNo. of survivors/total no. of miceSurvival (%)Mean no. of days to death ± SD
104.010/10100>219/109019.9 ± 3.5
104.58/108018.6 ± 5.16/106016.4 ± 6.0
105.05/105015.4 ± 5.65/105014.9 ± 6.5
106.00/1006.2 ± 1.00/1006.2 ± 1.0
  • a DBA/2 mice infected with different doses of chimeric viruses were monitored for 21 days to determine the number of mice that died and the mean number of days to death. Control mice were treated only with PBS (data not shown).