Pediatricians should ensure children who recently entered the U.S. are vaccinated against all three types of poliovirus, health officials said Thursday.
Physicians will have to verify immunization status through documentation instead of antibody testing, according to the Centers for Disease Control and Prevention (CDC) guidance.
“Given the large number of refugees coming from different countries who may have different schedules, they (the CDC) wanted to clarify what would be considered an up-to-date vaccination in the U.S.,” said Yvonne A. Maldonado, M.D., FAAP, vice chair of the AAP Committee on Infectious Diseases who provided input on the guidance.
The Academy and the CDC’s Advisory Committee on Immunization Practices recommend children in the U.S. receive four doses of inactivated polio vaccine (IPV), which protects against all three virus types. The immunization schedule calls for doses to be given at ages 2 months, 4 months, 6 through 18 months, and 4 through 6 years and lays out additional guidance on timing and catch-up vaccination.
While wild poliovirus type 2 has been declared eradicated, people in countries using live attenuated vaccines could contract a vaccine-derived type 2 virus, according to the CDC. That led 155 countries last year to switch from a live attenuated trivalent oral poliovirus vaccine (tOPV) to a bivalent vaccine that contains types 1 and 3.
The CDC’s updated guidance published Thursday in the Morbidity and Mortality Weekly Report calls for children living in the U.S. but vaccinated abroad to be vaccinated against all three types. Doctors must rely on documentation alone to determine a child’s status.
“Right now there are few laboratories that have the type 2 virus because we don’t want it reintroduced, so serologic testing for all three types is generally not available,” said Walter A. Orenstein, M.D., FAAP, lead author of the 2015 AAP clinical report on polio eradication who also provided input on the CDC guidance.
Vaccination in other countries may be accepted if tOPV or IPV was used on a similar or accelerated schedule to that of the U.S. The guidance details acceptable intervals. If both were used, the total doses to complete the series should mirror U.S. recommendations. If a child only received tOPV and the doses were given before age 4 years, he or she should receive one dose of IPV at 4 years or older, at least six months after the tOPV vaccination.
Children under age 18 who do not have documented evidence of tOPV or IPV should be revaccinated with IPV using the U.S. schedule, according to the CDC.
“If you’re not certain that a child received a trivalent vaccine, you should not accept those doses as adequate and (should) revaccinate that child,” Dr. Orenstein said.
