The Potential Contribution of Supplementary Immunization Activities to Routine Immunization in Kebbi State, Nigeria

Measles outbreak investigation in Berhet District, North Shewa, Ethiopia

Introduction

Measles, though usually self-limiting, can have severe consequences influenced by factors such as vaccination and nutrition, notably vitamin A deficiency and malnutrition. Despite progress, contextual changes and implementation issues have hampered efforts, resulting in increased outbreaks and cases of measles. This study seeks to pinpoint outbreak features, risk factors, and strategies for preventing and controlling measles.

Methods

A descriptive cross-sectional study and a 1:2 unmatched case-control study design were employed. All 101 suspected measles cases listed on the line-list were included in the descriptive research, with 60 measles patients and 120 controls included in the case-control investigation. Line-list data were cleaned and analyzed using a pivot table in Microsoft Excel 2016. Subsequently, the data were cleaned, entered into Epi Info 7.2, and exported to SPSS 26 for analysis.

Results

Twenty cases occurred per 10,000 individuals. Men accounted for 67.3% of cases, with ages ranging from 5 months to 45 years and mean and standard deviations of 9.6 and 7.6, respectively. Age group of 5-14 years comprised 57.4% of cases, followed by 1-4 years with 24.8%. Being unvaccinated against measles showed an adjusted odds ratio (AOR) of 12.06 (95% CI: 3.12-46.52). Travel history to regions with active cases had an AOR of 5.73 (95% CI: 1.78-18.38). Contact with a measles patient showed an AOR of 10.3 (95% CI: 3.48-30.5). Understanding the measles transmission mechanism had an AOR of 0.164 (95% CI: 0.049-0.55), and awareness of the disease's preventability had an AOR of 0.233 (95% CI: 0.67-0.811). All factors were independently associated with the illness.

Conclusion

This outbreak affected a broader age range with a high attack rate, mainly in the age group of 5-14-years. Over 35% of cases lacked measles vaccination, indicating low administrative vaccine coverage. Factors contributing to the outbreak include lack of measles vaccination, travel to areas with active disease, contact with cases, and insufficient knowledge of measles transmission and prevention strategies among mothers and caregivers.

Zero- or missed-dose children in Nigeria: Contributing factors and interventions to overcome immunization service delivery challenges

'Zero-dose' refers to a person who does not receive a single dose of any vaccine in the routine national immunization schedule, while 'missed dose' refers to a person who does not complete the schedule. These peopleremain vulnerable to vaccine-preventable diseases, and are often already disadvantaged due to poverty, conflict, and lack of access to basic health services. Globally, more 22.7 million children are estimated to be zero- or missed-dose, of which an estimated 3.1 million (∼14 %) reside in Nigeria.We conducted a scoping review tosynthesize recent literature on risk factors and interventions for zero- and missed-dosechildren in Nigeria. Our search identified 127 papers, including research into risk factors only (n = 66); interventions only (n = 34); both risk factors and interventions (n = 18); and publications that made recommendations only (n = 9). The most frequently reported factors influencing childhood vaccine uptake were maternal factors (n = 77), particularly maternal education (n = 22) and access to ante- and perinatal care (n = 19); heterogeneity between different types of communities - including location, region, wealth, religion, population composition, and other challenges (n = 50); access to vaccination, i.e., proximity of facilities with vaccines and vaccinators (n = 37); and awareness about immunization - including safety, efficacy, importance, and schedules (n = 18).Literature assessing implementation of interventions was more scattered, and heavily skewed towards vaccination campaigns and polio eradication efforts. Major evidence gaps exist in how to deliver effective and sustainable routine childhood immunization. Overall, further work is needed to operationalise the learnings from these studies, e.g. through applying findings to Nigeria's next review of vaccination plans, and using this summary as a basis for further investigation and specific recommendations on effective interventions.

Impact and effect mechanisms of mass campaigns in resource-constrained health systems: quasi-experimental evidence from polio eradication in Nigeria

Background

Mass campaigns are a key strategy for delivering life-saving interventions under Global Health Initiatives, especially in weak health system contexts. They are frequently designed parallel to the health system to rapidly achieve programme targets such as vaccination coverage, but we lack quantitative evidence demonstrating their impact and effect mechanisms on health system performance at sub-/national level. This longitudinal study responds to this gap through an analysis of polio eradication campaigns in Nigeria.

Methods

Using four rounds of Demographic and Health Surveys in Nigeria between October 2000 and December 2017, we created a longitudinal dataset containing 88 881 under-5 children/pregnancies. We estimated the relationships between individuals’ campaign exposure and health system performance indices (full RI schedule attainment, maternal healthcare services utilisation and child survival) using multilevel, mixed-effects regression models applied nationally and stratified by the six geopolitical zones in Nigeria.

Results

Nationally, high-frequency mass campaigns had detrimental health systems effects that potentially left 3.6 million children deprived of full immunisation. The frequency of campaigns was most concentrated in regions with weak health systems, where the operations of RI were disrupted, alongside negative effects on child survival and institutional delivery. In contrast, regions with relatively strong health systems and few campaigns experienced beneficial effects on maternal healthcare service utilisation.

Conclusions

As we provide evidence that well-functioning health systems can benefit from mass campaigns under Global Health Initiatives, our work also challenges the established wisdom to intensify mass campaigns in weaker health systems to bypass service provision bottlenecks. Mass campaigns do not inherently benefit or damage a health system, but frequent campaigns in weak health system contexts can impede service provision. We call for an additional burden of proof and active efforts to integrate mass campaigns into routine health services by harmonising implementation plans and service delivery in weak health system contexts.

Evaluation of measles vaccination coverage in Lincang City, Yunnan Province, China

Background: Lincang City in Yunnan Province on the China-Myanmar border, has reached the World Health Organization recommended coverage (95%) for measles-containing vaccine (MCV), but measles outbreaks still occur. We conducted a survey in Lincang City to determine the measles vaccination status of children on the China-Myanmar border.Methods: We used multistage sampling among children aged 8-83 months. Information on measles vaccination status was obtained from the child's vaccination certificate, and serum samples were tested using commercially available ELISA kits.Results: A total of 938 children were surveyed. The vaccination coverage rate was 98.9% (95% CI: 98.2-99.6%) for measles-containing vaccine dose 1 (MCV1), and 95.8% (95% CI:94.9-96.7%) for measles-containing vaccine dose 2 (MCV2). The timely vaccination coverage rate was 52.0% (95% CI:48.8-55.2%) for MCV1, and 74.1% (95% CI: 82.9-89.0%) for MCV2. The timely-and-complete vaccination coverage rate was 41.0% (95% CI: 36.7-45.3%). The median delay period was 33 (95% CI: 27-39) days for MCV1, and 196 (95% CI: 146-246) days for MCV2. The seropositivity rate in children aged less than 7 years was 94.0% (95% CI: 92.5-95.5%) with a geometric mean titer of 1210.1 mIU/mL.Conclusions: The MCV coverage was high, but timely and timely-and-complete vaccination coverage were low and insufficient to prevent measles outbreaks. It is necessary to add the timely and timely-and-complete vaccination coverage as indicators of vaccination to provide a more complete picture of measles immunization status.