Fig. 2
Viral dose selection and evaluation of the impact on nAb titers. A total of 16 samples were tested. Each dot/square/triangle represents the geometric mean titer (GMT) retrieved from three independent tests of a single serum sample tested in duplicate in each test at different viral doses (500, 2000 and 6000 TCID50 ml−1) for hMPV-A1; the y axis shows 50% neutralizing titer (NT) expressed as the reciprocal of the serum dilution. The lower limit of detection was set at 5, which is half of the reciprocal of the first serum dilution in plates (dashed black line). Cut-off for the calculation of the 50% NT was determined by applying the formula: cut-off = ((average of VC wells- average of CC wells)/2) + average of CC wells. CC: cell control; VC: viral control.
