Progress and gaps in poliovirus immunity: Evidence from a serological survey of children aged 6-23 months in high-risk districts of Pakistan.

ABSTRACT: Wild poliovirus remains endemic in Pakistan and Afghanistan despite global progress. We quantified immunity to poliovirus types 1-3 among children aged 6-23 months in 44 high-risk districts (2022-2023) using a cross-sectional serosurvey with probability proportional to size (PPS) cluster sampling. We enrolled 20,680 children (10,112 aged 6-11 months; 10,568 aged 12-23 months). Seroprevalence among 6-11-month-olds was 94.5% (type 1), 44.6% (type 2), and 88.0% (type 3); among 12-23-month-olds, it was 95.9%, 53.8%, and 91.2%, respectively. Type 1 seropositivity was highest across provinces; type 3 exceeded 90% except in Balochistan and KP; type 2 was lowest everywhere. Younger children have lower immunity. In multivariable models, residence in Balochistan predicted reduced seroprotection (AOR

SUBMITTER: Hussain I 

PROVIDER: S-EPMC12852092 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature