Toxicity and virulence of different <i>Salmonella</i> strains in BALB/c mice.

<p>Mice (5 animals per group) were either inoculated intramuscularly with the commercial H5N1 (cv-H5N1) and H1N1 vaccines (cv-H1N1) or intragastrically with PBS, the wild-type strain ST14028 (1 × 10³ CFU), and vaccine strain SL368 (1 × 10⁹ CFU) carrying the empty vector construct pVAX1 (Sal-vector) and constructs p5HA and p5NA (Sal-HA-NA). The mortality of the animals was monitored for 60 days. Humane (non-lethal) endpoints were used during the experiments and mice were euthanized with overdose inhalational CO₂ to limit suffering, when they exhibited weight loss of more than 30%, lethargy, ruffled hair coat, or hunched posture.