Asian Journal of Immunology

Dose-dependent Immunomodulatory Effects of Edible Chalk (Nzu) in Phenylhydrazine- induced Immune Dysfunction in Female Wistar Rats

Kanayo Mercy Odia, Joshua Ebirieng Gogo, Nicholas Asiwe — Mon, 12 Jan 2026 00:00:00 +0000

Background: Edible chalk (Nzu), a geophagic kaolin widely consumed in several African communities, particularly among women, has been associated with both perceived health benefits and potential toxicological risks. This study investigated the immunomodulatory effects of edible chalk in a phenylhydrazine (PHZ)-induced model of oxidative stress and immune disruption in female Wistar rats.

Methods: This study adopted a randomized controlled experimental design. Thirty adults female Wistar rats were randomly assigned into six groups (n = 5): normal control; PHZ-only group (0.5 ml intraperitoneally); PHZ plus Fesolate (65 mg/kg, positive control); and three treatment groups receiving PHZ followed by edible chalk at doses of 400, 600, or 800 mg/kg body weight, administered orally once daily for 22 days. Immunological assessment included serum quantification of immunoglobulins (IgA, IgM, and IgG) and pro-inflammatory cytokines (IL-1 and IL-6) using enzyme-linked immunosorbent assay (ELISA) and automated immunoturbidimetric techniques. Splenic histoarchitecture was examined using hematoxylin and eosin staining to assess structural and cellular integrity.

Results: PHZ administration induced marked immune dysregulation, evidenced by significantly elevated IL-6 levels and pronounced reductions in immunoglobulin concentrations, indicating concurrent inflammation and humoral immunosuppression. Treatment with edible chalk at 400 and 600 mg/kg significantly ameliorated these alterations. The 600 mg/kg dose demonstrated the most effective immunorestorative activity, normalizing immunoglobulin levels, suppressing inflammatory cytokine expression, and promoting recovery of splenic white and red pulp architecture. Conversely, the 800 mg/kg dose exacerbated immune dysfunction, resulting in further immunoglobulin depletion, heightened IL-6 expression, and severe splenic histopathological damage characterized by lymphoid depletion and architectural distortion.

Conclusion: Edible chalk exhibits a biphasic, dose-dependent immunological effect, with moderate doses conferring immunoprotective and anti-inflammatory benefits, while excessive intake induces significant immunotoxicity, underscoring important public health concerns regarding its unregulated consumption, especially among pregnant women.

Factors Associated with Uptake of Rotavirus Vaccination among Mothers of Children under Five in Umuahia North, Abia State, Nigeria

Uka-Kalu, Ezinne Chioma, Okeke, Onyinyechi Okore — Tue, 27 Jan 2026 00:00:00 +0000

Background: Rotavirus is a leading cause of severe diarrhea among children under five years of age globally, with Nigeria bearing a significant burden. Despite the introduction of the rotavirus vaccine into Nigeria’s national immunisation schedule, uptake remains suboptimal in many regions.

Aim: This study aimed to assess the factors that influence the uptake of rotavirus vaccination among mothers of under-five children in Umuahia North Local Government Area, Abia State.

Methods: A cross-sectional design was employed, involving 384 mothers selected through multistage sampling. Data were collected using a structured, self-administered questionnaire and analyzed using descriptive and inferential statistics.

Results: The findings revealed that only 93 (24.2%) of the children had received at least one dose of the rotavirus vaccine, and completion of the three-dose schedule was rare. Awareness and knowledge of the vaccine were notably low, as only 24.2% of mothers had ever heard of it, with health workers being the main source of information. The major reasons for non-uptake included lack of awareness (31.3%), distance to health facilities (15.6%), and fear of side effects (9.6%). Factors significantly influencing uptake included occupation and prior awareness of the vaccine (p < 0.05), while other socio-demographic variables were not statistically significant.

Conclusion: The study concludes that low awareness, inadequate health education, and access-related challenges significantly hinder rotavirus vaccine uptake. Strengthening community health education, expanding vaccine access, and empowering healthcare workers with better communication tools are recommended to improve coverage and reduce rotavirus-related morbidity and mortality in the area.

Challenges in Reaching Full Coverage of Routine Immunization in Nigeria: A Review

Saratu Bashir Aminu, Mujahid Musa, Yusuf Adeiza Kashim — Wed, 14 Jan 2026 00:00:00 +0000

Routine childhood immunization remains one of the most cost-effective public health interventions, yet Nigeria continues to experience substantial gaps in coverage, timeliness, and completion of recommended vaccine series. These gaps are not uniform: they cluster by geography, socioeconomic position, maternal education, service accessibility, and health system performance, and they are amplified by insecurity, mobility, and trust deficits. This review synthesizes evidence on routine immunization coverage and its determinants in Nigeria, focusing on multi-level drivers that shape vaccination initiation, continuation, and completion. We highlight consistent demand-side determinants such as caregiver education and empowerment, household wealth, health service utilization, and information exposure; supply-side determinants such as service readiness, health worker practices, vaccine logistics, and missed opportunities; and contextual determinants such as place of residence, subnational inequities, and conflict-related disruption. We further discuss the growing programmatic emphasis on “zero-dose” and under-immunized children, and summarize promising intervention directions including community-engaged delivery, facility-based quality improvement to reduce missed opportunities, and targeted demand-generation combined with reliable service availability. The review concludes that Nigeria’s coverage challenges are best understood as an interaction between household vulnerability and system reliability, mediated by local context. Sustainable gains require integrated strategies that strengthen primary health care delivery, improve data-driven microplanning, reduce dropout through continuity of care, and tailor approaches to high-risk geographies and populations.