Printable Copy |
John J1, Giri S2, Karthikeyan AS2, Lata D2, Jeyapaul S1, Rajan AK3, Kumar N2, Dhanapal P2, Venkatesan J2, Mani M2, Hanusha J2, Raman U2, Moses PD3, Abraham A3, Bahl S4, Bandyopadhyay AS5, Ahmad M6, Grassly NC7, Kang G2.
J Infect Dis. 2017 Feb 15;215(4):529-536. doi: 10.1093/infdis/jiw595.
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.
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.
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).
Protection against poliovirus remained elevated 6 and 11 months after an IPV boost, although at a lower level than reported at 1 month.