The Duration of Intestinal Immunity After an Inactivated Poliovirus Vaccine Booster Dose in Children Immunized With Oral Vaccine: A Randomized Controlled Trial

J Infect Dis. 2017 Feb 15;215(4):529-536. doi: 10.1093/infdis/jiw595.


Background: In 2014, 2 studies showed that inactivated poliovirus vaccine (IPV) boosts intestinal immunity in children previously immunized with oral poliovirus vaccine (OPV). As a result, IPV was introduced in mass campaigns to help achieve polio eradication.

Methods: We conducted an open-label, randomized, controlled trial to assess the duration of the boost in intestinal immunity following a dose of IPV given to OPV-immunized children. Nine hundred healthy children in Vellore, India, aged 1-4 years were randomized (1:1:1) to receive IPV at 5 months (arm A), at enrollment (arm B), or no vaccine (arm C). The primary outcome was poliovirus shedding in stool 7 days after bivalent OPV challenge at 11 months.

Results: For children in arms A, B, and C, 284 (94.7%), 297 (99.0%), and 296 (98.7%), respectively, were eligible for primary per-protocol analysis. Poliovirus shedding 7 days after challenge was less prevalent in arms A and B compared with C (24.6%, 25.6%, and 36.4%, respectively; risk ratio 0.68 [95% confidence interval: 0.53-0.87] for A versus C, and 0.70 [0.55-0.90] for B versus C).

Conclusions: Protection against poliovirus remained elevated 6 and 11 months after an IPV boost, although at a lower level than reported at 1 month.

Clinical trials registration: CTRI/2014/09/004979.

Keywords: human challenge; inactivated vaccine; oral vaccine; poliovirus; mucosal immunity.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Antibodies, Neutralizing / blood
  • Antibodies, Neutralizing / immunology
  • Antibodies, Viral / blood
  • Antibodies, Viral / immunology
  • Child, Preschool
  • Dose-Response Relationship, Immunologic
  • Feces / virology
  • Female
  • Humans
  • Immunity, Mucosal
  • Immunization Schedule
  • Immunization, Secondary
  • India
  • Infant
  • Intestines / virology
  • Male
  • Poliomyelitis / prevention & control*
  • Poliovirus
  • Poliovirus Vaccine, Inactivated / administration & dosage
  • Poliovirus Vaccine, Inactivated / therapeutic use*
  • Poliovirus Vaccine, Oral / administration & dosage
  • Poliovirus Vaccine, Oral / therapeutic use*
  • Treatment Outcome
  • Vaccination / methods
  • Virus Shedding


  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Poliovirus Vaccine, Inactivated
  • Poliovirus Vaccine, Oral