This statement describes a modification of the recommended routine schedule for administering trivalent oral poliomyelitis vaccine (OPV). The American Academy of Pediatrics previously has recommended that healthy children receive a three-dose primary series of OPV at 2, 4, and 15 to 18 months of age and a fourth dose at the time of school entry (4 to 6 years of age).1 Available data indicate that the response rates to the third dose of OPV administered at 6 months of age are as good as the rates following administration of this dose at 15 to 18 months of age. Completion of the three-dose primary series at an earlier age will help health care providers induce immunity against poliomyelitis at an early age.
Although wild type poliomyelitis has not caused disease in the United States for many years, the virus remains prevalent in many countries. Continued introduction of the virus into the United States by travelers could result in transmission and disease if high levels of immunity are not maintained in preschool age children. For example, wild type poliovirus type 3 was recently introduced into Canada by a religious sect that did not believe in immunization.2 The virus was probably imported from the Netherlands, where a small epidemic of poliomyelitis occurred in members of the same sect in 1992 and 1993.3
SERUM ANTIBODY RESPONSE FOLLOWING OPV ADMINISTRATION
After two doses of OPV are administered at 2 and 4 months of age, 89 to 100% of children vaccinated in the United States have evidence of humoral immunity to poliomyelitis types 1 and 3, and 99 to 100% have immunity to type 2 (Table).
- Copyright © 1994 by the American Academy of Pediatrics