FIG 1.

Plaque reduction neutralization (PRN) and commercial ELISA testing of infant sera pre- and postvaccination. Serum samples were collected from 37 infants at prevaccination (T₀), 2 to 3 months after first dose of MMR (T₁), 4 to 7 months after first MMR (T₂; also collected immediately before administration of second MMR), 2 to 4 months after second MMR (T₃), 2 years after first MMR (T₄), and 4 years after first MMR (T₅). Sera were tested by PRN (A), and ROC analysis was performed using the sera collected at the T₀ and T₃ time points as the negative controls and the test samples, respectively (B). Sera were tested by commercial ELISA (C) and ROC analysis of the commercial ELISA was performed using the T₀ and T₃ time points (D). PRN and commercial ELISA ISR values were compared and analyzed by linear-regression for the T₃ (E) and T₄ (F) time points.