Table 1.

Ratio of Number of Cases of Vaccine-associated Paralytic Poliomyelitis to Number of Doses of Trivalent OPV* Distributed, United States, 1980 Through 1994

Case CategoryRatio (No. of Cases to Millions of Doses of
OPV Distributed)
All
doses
First
dose
Subsequent
doses
Recipient1:6.2 (49)1:1.4 (40)1:27.2 (9)
Contact1:7.6 (40)1:2.2 (26)1:17.5 (14)
Community acquired1:50.5 (6)NANA  
Immunologically
abnormal
1:10.1 (30)1:5.8 (11)1:12.9 (19)
Total1:2.4 (125)1:0.75 (77)1:5.1 (48)
  • * Live, oral poliovirus vaccine (attenuated).

  • NA indicates not applicable.

  • Because the denominator is doses of OPV distributed, the calculated ratio is low. However, if the denominator is the number of immunodeficient infants born each year, the risk of VAPP in immunodeficient infants is 3200 to 6800-fold higher than in immunocompetent infants.27