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Rotavirus infection remains an important cause of morbidity and mortality in children. The introduction of vaccination programs in more than 100 countries has contributed to a decrease in hospitalizations and mortality. This study investigates the epidemiological impact of the rotavirus vaccine ROTAVAC® in the Palestinian Territories, the first country to switch from ROTARIX® to this new vaccine.Clinical surveillance data was collected fromchildren younger than 5attendingoutpatient clinics throughout Gaza withdiarrhea between 2015 and 2020. The incidence of all-cause diarrhea was assessed using an interrupted time-series approach. Rotavirus prevalence was determined at the Caritas Baby Hospital in the West Bank usingELISA on stool specimen of children younger than 5with diarrhea. Genotyping was performed on 325 randomly selected rotavirus-positive samples from January 2015 through December 2020 using multiplex PCR analysis.Average monthly diarrhea casesdropped by 16.7% annually fromintroduction of rotavirus vaccination in May 2016 to the beginning of the SARS-CoV-2 epidemic in March 2020 for a total of 53%. Case count declines were maintained afterthe switchto ROTAVAC® in October 2018. Rotavirus positivity in stool samples declined by 67.1% over the same period without change followingthe switch to ROTAVAC®. The distribution of predominant genotypes in rotavirus-positive stool samples changed from a pre-vaccination G1P [8] to G9P[8] and G12P[8] during the ROTARIX® period and G2P[4] after the introduction of ROTAVAC®.ROTAVAC® has shown epidemiological impact on par with ROTARIX® after its introduction to the national immunization schedule in the Palestinian Territories. A molecular genotype shift from a pre-vaccination predominance of G1P[8] to a current predominance of G2P[4] requires more long-term surveillance.

Background: Inactivated trivalent poliovirus vaccine (IPV) induces humoral immunity, which protects against paralytic poliomyelitis but does not induce sufficient mucosal immunity to block intestinal infection. We assessed the intestinal immunity in healthy adults in Belgium conferred by a co-formulation of IPV with the mucosal adjuvant double mutant Labile Toxin (dmLT) derived from Escherichia coli.Methods: Healthy fully IPV-vaccinated 18-45-year-olds were randomly allocated to three groups: on Day 1 two groups received one full dose of IPV (n = 30) or IPV + dmLT (n = 30) in a blinded manner, and the third received an open-label dose of bivalent live oral polio vaccine (bOPV types 1 and 3, n = 20). All groups received a challenge dose of bOPV on Day 29. Participants reported solicited and unsolicited adverse events (AE) using study diaries. Mucosal immune responses were measured by fecal neutralization and IgA on Days 29 and 43, with fecal shedding of challenge viruses measured for 28 days. Humoral responses were measured by serum neutralizing antibody (NAb).Results: Solicited and unsolicited AEs were mainly mild-to-moderate and transient in all groups, with no meaningful differences in rates between groups. Fecal shedding of challenge viruses in both IPV groups exceeded that of the bOPV group but was not different between IPV and IPV + dmLT groups. High serum NAb responses were observed in both IPV groups, alongside modest levels of fecal neutralization and IgA. Conclusions: Addition of dmLT to IPV administered intramuscularly neither affected humoral nor intestinal immunity nor decreased fecal virus shedding following bOPV challenge. The tolerability of the dose of dmLT used in this study may allow higher doses to be investigated for impact on mucosal immunity.Registered on ClinicalTrials.gov - NCT04232943.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

Highlights • Nigeria’s national survey estimates of DPT3 and MCV1 coverage fluctuate greatly in recent years. • Much of the variation results from differences in surveys weights, not coverage. • Both USAID DHS and UNICEF MICS allow weights to vary from round-to-round. • Nigeria’s National Nutrition & Health Survey weights do not vary much due to post-stratification. • To compare results from surveys proximate in time, use similar strata weights for clarity., National vaccination coverage estimates from household surveys are widely used in monitoring and planning of immunization programs. In Nigeria, survey-reported national coverage estimates have shown large fluctuations in the past few years. In this paper, we examine the impact of state-level survey weighting on Nigeria’s national vaccination coverage estimation. In particular, we focus three vaccination-related outcomes among children aged 12–23 months: the coverage of the third dose of diphtheria, pertussis, and tetanus vaccine (DPT3); the coverage of the first dose of measles-containing vaccine (MCV1); and the availability rate of home-based vaccination record (HBR). We compare the sample selection and weight assignment of three major survey programs in Nigeria, and show that considerable portions of the changes in survey-reported national coverage estimates can be explained by shifts in state-level weights. Our analysis demonstrates the importance of state weighting method in estimating aggregated national coverage figures and provides important context for interpreting changes in coverage estimates between surveys in the future.

The globally synchronized removal of the attenuated Sabin type 2 strain from the oral polio vaccine (OPV) in April 2016 marked a major change in polio vaccination policy. This change will provide a significant reduction in the burden of vaccine-associated paralytic polio (VAPP), but may increase the risk of circulating vaccine-derived poliovirus (cVDPV2) outbreaks during the transition period. This risk can be monitored by tracking the disappearance of Sabin-like type 2 (SL2) using data from the polio surveillance system. We studied SL2 prevalence in 17 countries in Africa and Asia, from 2010 to 2016 using acute flaccid paralysis surveillance data. We modeled the peak and decay of SL2 prevalence following mass vaccination events using a beta-binomial model for the detection rate, and a Ricker function for the temporal dependence. We found type 2 circulated the longest of all serotypes after a vaccination campaign, but that SL2 prevalence returned to baseline levels in approximately 50days. Post-cessation model predictions identified 19 anomalous SL2 detections outside of model predictions in Afghanistan, India, Nigeria, Pakistan, and western Africa. Our models established benchmarks for the duration of SL2 detection after OPV2 cessation. As predicted, SL2 detection rates have plummeted, except in Nigeria where OPV2 use continued for some time in response to recent cVDPV2 detections. However, the anomalous SL2 detections suggest specific areas that merit enhanced monitoring for signs of cVDPV2 outbreaks.