Polio, or poliomyelitis, is an infectious viral disease which mainly affects young children. The condition upsets a person’s nervous system and can cause paralysis. Thanks to the polio vaccine, dedicated healthcare professionals, and parents who vaccinate their children on schedule, polio has been eradicated from this country for more than 30 years.

Oral poliovirus vaccine (OPV) that is administered orally can be given by volunteers and does not require trained health workers or sterile injection equipment. A new research published in The Lancet reveals that giving an extra dose of inactivated poliovirus vaccine (IPV) to all children under the age of 5 could help to speed up eradication efforts.

Funded by Bill & Melinda Gates Foundation, the study highlights that although OPV is highly effective, easy to administer, and relatively inexpensive, its ability to generate a strong intestinal immunity to infection wanes with time, thus permitting the transmission of infection by immunized children. At the same time, inactivated poliovirus vaccine (IPV) does not induce an intestinal mucosal immune response, but could boost protection in children who are mucosally primed through previous exposure to OPV.

For the study purpose, an open-label, randomized controlled trial was done in children aged 1-4 years, who were healthy. They had not received IPV before and had had their last dose of OPV at least 6 months before enrolment. 450 children were enrolled and randomly assigned into study groups. 225 children received IPV and 225 no vaccine.

It was found that the additional IPV dose substantially boosted levels of protective antibodies in the blood and intestinal immunity against poliovirus compared with no vaccine. One week after challenge with OPV, 43 (19%) and 57 (26%) children given no vaccine shed serotype 1 or 3 poliovirus compared with 27 (12%) and 17 (8%) of those receiving IPV. Among children in the no vaccine group, the first dose of bivalent OPV did not reduce poliovirus shedding following a second challenge dose of this vaccine.

According to the senior author of the study, “The substantial benefit of using IPV rather than further doses of OPV to boost intestinal immunity in children within the typical age range for mass vaccination supports its use as part of the global eradication program”.

Though U.S is free from poliovirus, it is still a threat in some countries. It is crucial to get each child vaccinated on schedule. IPV is given as a series of four shots, at 2 months, 4 months, 6 to 18 months, and again at 4 to 6 years of age. Most health insurance plans cover the cost of vaccines. The vaccine is billed under CPT code 90713 – Poliovirus vaccine (IPV), inactivated, for subcutaneous or intramuscular use.