FIG 12.
Humoral responses to pH1N1 LAIV viral infections. Six- to 8-week-old female C57BL/6 mice (n = 5) were infected i.n. with 1 × 102 PFU of the indicated pH1N1 LAIV viruses. (A to C) At 21 days p.i., mice were bled and sera were collected and evaluated by ELISA for IgG antibodies against total influenza virus proteins using cell extracts of pH1N1 virus-infected MDCK cells (A) or recombinant pH1N1 HA (B) or NA (C) protein. OD, optical density. (D) HAI titers from mock (PBS)-infected or infected mouse sera were calculated.