Comparison of IPV to tOPV week 39 boost of primary OPV vaccination in Indian infants: an open labelled randomized controlled trial

Abstract

BackgroundThe final endgame strategy of global polio eradication initiative includes switching from trivalent oral poliovirus vaccines (tOPV) to bivalent oral polio vaccine (bOPV), and introduction of inactivated poliovirus vaccine (IPV). This study compares IPV with tOPV week 39 boost in Indian infants.MethodsStarting 28 March 2012, we enrolled 372 Indian infant-mother pairs from Kolkata, India in an open-label, block-randomized, controlled trial comparing a 39 week tOPV to an IPV boost among infants immunized with three doses of tOPV. The primary outcome was mucosal immunity to poliovirus as measured by fecal polio virus shedding after OPV challenge. The secondary outcome was humoral response as defined by >1:8 titers for neutralizing antibodies at week 40. Seroconversion was measured by change in level of antibody titers from week 18 to week 40. The analyses were performed by both intention-to-treat (ITT) and per-protocol (PP) comparing the occurrences of outcomes between the arms of the study.FindingsBoth the study arms provided equivalent mucosal immunity at 52 weeks with a total shedding prevalence of 28%. Vaccination with IPV resulted in significantly higher seroconversion rates for Polio type 2 (p = 0.03) and Polio type 3 (p < 0.01).ConclusionsThis study indicates that an IPV boost at week 39 is equivalent to tOPV in intestinal immunity, and provides higher seroconversion compared to tOPV. The major limitation of the study was the additional OPV doses receive by infants during pulse polio immunization resulted in additional mucosal boosting, diminishing the impact of IPV or tOPV boost at week 39. However, IPV for OPV boost should prove to be a step forward in the global polio eradication initiative to reduce the problem of circulating vaccine-derived poliovirus (cVDPV).

Evolution in fecal bacterial/viral composition in infants of two central African countries (Gabon and Republic of the Congo) during their first month of life

“…This may explain the presence of the three poliovirus serotypes in some samples between D02 and D28, as previously reported by Kanungo et al . [ 74 ] in vaccinated Indian infants. Conversely, the initial source of the other viruses in the infant human gut is unknown, although inoculation from nosocomial, dietary and environmental sources is possible.…”

Antibody secreting B cells and plasma antibody response to rotavirus vaccination in infants from Kolkata India

“…Subjects were randomized to receive OPV and Inactivated Polio Vaccine (IPV) at 39 weeks of age. Additionally, all subjects were vaccinated with Rotarix ® as a part of the study [19] . Blood specimens (2 ml) were collected by venipuncture at baseline (i.e.…”

“…These ASCs appear in blood transiently ∼ 7 days after infection or vaccination and can be measured by enzyme linked immunospot (ELISPOT) assay [17] . To better understand this relationship, we integrate RV vaccine intervention within a large cohort study in Kolkata, India [19] . The primary objective of this study was to measure seropositivity (i.e.…”