Clinical score and H1N2-neutralizing antibody titers.
(A) From one week prior to the first infection until the end of the study either six or nine weeks post primary infection, piglets were daily monitored for clinical signs of disease. Auscultation score (solid line; 0 = physiologic, 1 = low-grade intensified vesicular, 2 = middle-grade intensified vesicular, 3 = high-grade intensified vesicular, 4 = bronchial, 5 = wheezing, 6 = rales, 7 = friction rub) and dyspnea score (dashed line; 0 = no dyspnea, 1 = dyspnea on exertion, 2 = dyspnea at rest, 3 = severe dyspnea) are shown for the three PBS-treated control animals (#1 to #3) and the six FLUAVsw-infected animals (#4 to #9). (B) Weekly collected serum samples were tested for H1N2-neutralizing antibodies by serum neutralization tests. Titers are expressed as the reciprocal neutralizing dose 50 (ND50). Data of PBS-treated (#1 to #3) and FLUAVsw-infected (#4 to #9) animals is shown in the time course following infections. (A and B) The background color in each diagram indicates different time spans: pre-infection (white), post primary infection (light grey) and post secondary infection (dark grey).