Fig 6. NS-LAIV candidates protect mice from lethal infection.

Groups of mice (n=12/group) were immunized by intranasal inoculation with the wild-type (WT), the NS-LAIVs (NS1-73, NS1-126, or NSΔ5) or inoculation media alone (Mock). (A) Neutralizing antibody levels in serum collected at 21 days post-immunization were determined by microneutralization assay (each dot represents an individual mouse). (B) Mice were challenged intranasally, 30 days post-immunization, with 5×10⁴ TCID₅₀ (∼100 LD₅₀) of a lethal mouse adapted variant of NY1682, and their weight was monitored for 10 days post challenge, error bars represent ± SEM (days 1-3, n=12; days 4-6, n=8; days 7-10 n=4). * Only 4/8 mice remained in the mock immunized group on day 6 post challenge because 4 mice were euthanized for humane reasons on day 5, and the remaining animals were euthanized on day 6. (C) Viral titers in the lungs were determined at 3 and 6 days post challenge. Each dot represents the virus titer of an individual mouse (n=4/group). Mock indicates animals that were mock-immunized and subsequently challenged. The LOD of the assays is indicated by the dotted line (A, & C). The graphs are representative of two independent experiments.