Table 1

Results obtained for serum samples tested using the CDC capture IgM EIA from 296 confirmed mumps cases, stratified by timing of serum collection and MMR vaccination status

No. of doses of MMR(n = samples)No. (%) of serum samples that were IgM positive in MMR group/no. collected:Total no. of samples positive in MMR group (%)
0–2 days after onseta≥3 days after onsetb
0 doses, n = 137/10 (70)2/3 (67)9/13 (69)
1 dose, n = 2512/23 (52)1/2 (50)13/25 (52)
2 doses, n = 15560/131 (46)17/24 (71)78/155 (50)
Unknown, n = 10329/76 (38)20/27 (74)49/103 (48)
Total108/240 (45)40/56 (71)148/296 (50)
  • a Median, 1.0 day; average, 0.78 days.

  • b Median, 5.0 days; average, 4.0 days.