"Trained Immunity" from Mycobacterium spp. exposure (BCG vaccination and environmental) may have an impact on the incidence of early childhood leukemia

Preventive variables for childhood leukemia incidence (LI) remain unknown. Past assertions that childhood vaccinations, especially BCG, may be potentially protective have remained disputed for over five decades because of the lack of a unifying framework to explain variable outcomes in different studies. An examination of the early childhood LI for 2020 in European Region countries with supposedly similar underlying confounders but differential childhood vaccination coverage displays negative covariation with prevailing Mycobacterium spp. exposure in BCG-vaccinated children. The childhood LI in 0-4-year-old populations with >90% childhood BCG vaccination coverage is found to be strongly but negatively correlated with prevailing tuberculin immunoreactivity [r(24): -0.7868, p-value: < 0.0001]. No such correlation existed for the LI in 0-4-year-old populations without BCG vaccinations, though weak associations are hinted at by the available data for MCV2, PCV3, and DTP3 vaccinations. We hypothesize that early childhood BCG vaccination "priming" and subsequent "trained immunity" augmentation by "natural" boosting from Mycobacterium spp. exposure play a preventive and protective role in childhood LI. The non-consideration of prevailing "trained immunity" could have been a cause behind the conflicting outcomes in past studies. Exploratory studies, preferably performed in high-burden countries and controlling for the trained-immunity correlate and other potential confounders, would be warranted in order to establish a role for BCG vaccination and early-life immune training (or lack thereof) in childhood LI and help put the current controversy to rest.

Access to skilled attendant at birth and the coverage of the third dose of diphtheria-tetanus-pertussis vaccine across 14 West African countries - an equity analysis

BACKGROUND

Universal Health Coverage (UHC) remains a critical public health goal that continues to elude many countries of the global south. As countries strive for its attainment, it is important to track progress in various subregions of the world to understand current levels and mechanisms of progress for shared learning. Our aim was to compare multidimensional equity gaps in access to skilled attendant at birth (SAB) and coverage of the third dose of Diphtheria-Tetanus-Pertussis (DTP3) across 14 West African countries.

METHODS

The study was a cross sectional comparative analysis that used publicly available, nationally representative health surveys. We extracted data from Demographic and Health Surveys, and Multiple Indicator Cluster Surveys conducted between 2010 and 2017 in Benin, Burkina Faso, Cote d' Ivoire, The Gambia, Ghana, Guinea, Guinea Bissau, Liberia, Mali, Niger, Nigeria, Senegal, Sierra Leone and Togo. The World Health Organization's Health Equity Assessment Toolkit (HEAT Plus) software was used to evaluate current levels of intra-country equity in access to SAB and DTP3 coverage across four equity dimensions (maternal education, location of residence, region within a country and family wealth status).

RESULTS

There was a general trend of higher levels of coverage for DTP3 compared to access to SAB in the subregion. Across the various dimensions of equity, more gaps appear to have been closed in the subregion for DTP3 compared to SAB. The analysis revealed that countries such as Sierra Leone, Liberia and Ghana have made substantial progress towards equitable access for the two outcomes compared to others such as Nigeria, Niger and Guinea.

CONCLUSION

In the race towards UHC, equity should remain a priority and comparative progress should be consistently tracked to enable the sharing of lessons. The West African subregion requires adequate government financing and continued commitment to move toward UHC and close health equity gaps.

Determinants of geographical inequalities for DTP3 vaccine coverage in sub-Saharan Africa

Childhood immunization is one of the most effective health interventions, making it a key indicator of progress towards universal health coverage. In the last decade, improvements in coverage have been made globally, however, slow progress has been documented in sub-Saharan Africa with considerable subnational variations. We explore potential drivers of equitable immunization services based on subnational DTP3 coverage estimates. Using vaccine coverage at the 5 by 5 km area from 2000 to 2016, we quantify inequality using three measures. We assess the shortfall inequality which is the average deviation across subnational units from that with the highest coverage for each country. Secondly we estimate the threshold index, the proportion of children below a globally set subnational coverage target, and lastly, a Gini coefficient representing the within-country distribution of coverage. We use time series analyses to quantify associations with immunization expenditures controlling for country socio-economic and population characteristics. Development assistance, maternal education and governance were associated with reductions in inequality. Furthermore, high quality governance was associated with a stronger relationship between development assistance and reductions in inequality. Results from this analysis also indicate that countries with the lowest coverage suffer the highest inequalities. We highlight growing inequalities among countries which have met national coverage targets such as South Africa and Kenya. In 2016, values for the shortfall inequality ranged from 1% to 43%, the threshold index from 0% to 100% and Gini coefficient from 0.01 to 0.37. Burundi, Comoros, Eswatini, Lesotho, Namibia, Rwanda, and Sao Tome and Principe had the least shortfall inequality (<5%) while Angola, Ethiopia and Nigeria had values greater than 40%. A similar picture was noted for the other dimensions of inequality among these particular countries. Immunization program investments offer promise in addressing inequality, however, domestic mechanisms for resource implementation and accountability should be strengthened to maximize gains in coverage.

NF-κB in the crosshairs: Rethinking an old riddle

Constitutive NF-κB signalling has been implicated in the pathogenesis of most human malignancies and virtually all non-malignant pathologies. Accordingly, the NF-κB pathway has been aggressively pursued as an attractive therapeutic target for drug discovery. However, the severe on-target toxicities associated with systemic NF-κB inhibition have thus far precluded the development of a clinically useful, NF-κB-targeting medicine as a way to treat patients with either oncological or non-oncological diseases. This minireview discusses some of the more promising approaches currently being developed to circumvent the preclusive safety liabilities of global NF-κB blockade by selectively targeting pathogenic NF-κB signalling in cancer, while preserving the multiple physiological functions of NF-κB in host defence responses and tissue homeostasis.

A cluster randomized trial to determine the effectiveness of a novel, digital pendant and voice reminder platform on increasing infant immunization adherence in rural Udaipur, India

BACKGROUND

Five hundred thousand children under the age of 5 die from vaccine preventable diseases in India every year. More than just improving coverage, increasing timeliness of immunizations is critical to ensuring infant health in the first year of life. Novel, culturally appropriate community engagement strategies are worth exploring to close the immunization gap. In our study, a digital NFC (Near Field Communication) pendant worn on black thread and voice call reminder system was tested for the effectiveness in improving DTP3 adherence within 2 monthly camps from DTP1 administration.

METHOD

A cluster randomized controlled trial was conducted in which 96 village health camps were randomized to 3 arms: NFC sticker, NFC pendant, and NFC pendant with voice call reminder in local dialect. Randomization was done across 5 blocks in the Udaipur District serviced by Seva Mandir from August 2015 to April 2016.

RESULTS

In terms of our three primary outcomes related to DTP3 adherence, point estimates show conflicting results. Two outcomes presented adherence in the control. DTP3 completion within two camps after DTP1 showed higher adherence in the Control (Sticker) (74.2%) arm compared to the Pendant (67.2%) and Pendant and Voice arms (69.3%). Likewise, the estimate for DTP3 completion within 180 days of birth in the Control (Sticker) (69.4%) arm was higher than estimates in the Pendant (57.4%) and Pendant and Voice arms (58.7%). However, one outcome displayed higher adherence in the intervention. DTP3 completion within two months from the time of registration was higher in the Pendant (37.7%) and Pendant and Voice arms (38.7%) compared to the Control (Sticker) arm (27.4%). In all primary outcomes, differences in adherence were statistically insignificant both before and after controlling for confounding factors. In terms of secondary outcomes, our results suggest that providing a necklace generated significant community discussion (H = 8.8796, df = 2, p = .0118), had strong satisfaction among users (χ2=26.039, df = 4, p < .0001), and resulted in increased visibility within families (grandmothers:χ2=34.023, df = 2, p < .0001, fathers: χ2=34.588, df = 2, p < .0001).

CONCLUSION

Neither the NFC necklace nor the necklace with additional voice call reminders in the local dialect directly resulted in an increase in infant immunization timeliness through DTP3, the primary outcome. Still our process outcomes suggest that our culturally symbolic necklace has potential to be an assistive tool in immunization campaigns. Follow-on work will seek to examine whether positive behavior change towards vaccines can be fostered with earlier engagement of this platform beginning in the prenatal stage, under a continuum of care framework.

Comparison of inflation of third dose diphtheria tetanus pertussis (DTP3) administrative coverage to other vaccine antigens

Third dose diphtheria tetanus pertussis (DTP3) administrative coverage is a commonly used indicator for immunization program performance, although studies have demonstrated data quality issues with administrative DTP3 coverage. It is possible that administrative coverage for DTP3 may be inflated more than for other antigens. To examine this, theory, we compiled immunization coverage estimates from recent country surveys (n=71) and paired these with corresponding administrative coverage estimates, by country and cohort year, for DTP3 and 4 other antigens. Median administrative coverage was higher than survey estimates of coverage for all antigens (median differences from 26 to 30%), however this difference was similar for DTP3 as for all other antigens. These findings were consistent when countries were stratified by income level and eligibility for Gavi funding. Our findings demonstrate that while country administrative coverage estimates tend to be higher than survey estimates, DTP3 administrative coverage is not inflated more than other antigens.

The performance of the expanded programme on immunization in a rural area of Mozambique

Vaccines are an effective public health measure. Vaccination coverage has improved in Africa in the last decades but has still not reached WHO/UNICEF target of at least 90% first-dose coverage for vaccines in the Expanded Programme on Immunization (EPI) implemented in Mozambique in 1979. There are concerns about reliability of vaccination coverage official data from low-income countries, and inequities in vaccine administration. We randomly sampled 266 under-five years children from Taninga, a poor rural area in Southern Mozambique under a Demographic surveillance system and collected data directly from the individual national health cards when available (BCG, DTP/HepB/Hib, Polio, Measles). We also collected data on socio-economic variables through an interview. Overall, only 5% of the participants did not receive all the doses of the vaccines included in the EPI in a timely manner (overall vaccination coverage 95%, 95% CI: 93.5-95.5%). The socio-economic status was homogenously low and no differences were found between vaccinated and unvaccinated children. Vaccination coverage in Taninga was very high, despite the low socio-economic status of the population. The high performance of the EPI in Taninga is an encouraging experience for achieving high vaccination coverage in low-income rural settings.

Drivers of routine immunization coverage improvement in Africa: findings from district-level case studies

There is limited understanding of why routine immunization (RI) coverage improves in some settings in Africa and not in others. Using a grounded theory approach, we conducted in-depth case studies to understand pathways to coverage improvement by comparing immunization programme experience in 12 districts in three countries (Ethiopia, Cameroon and Ghana). Drawing on positive deviance or assets model techniques we compared the experience of districts where diphtheria-tetanus-pertussis (DTP3)/pentavalent3 (Penta3) coverage improved with districts where DTP3/Penta3 coverage remained unchanged (or steady) over the same period, focusing on basic readiness to deliver immunization services and drivers of coverage improvement. The results informed a model for immunization coverage improvement that emphasizes the dynamics of immunization systems at district level. In all districts, whether improving or steady, we found that a set of basic RI system resources were in place from 2006 to 2010 and did not observe major differences in infrastructure. We found that the differences in coverage trends were due to factors other than basic RI system capacity or service readiness. We identified six common drivers of RI coverage performance improvement-four direct drivers and two enabling drivers-that were present in well-performing districts and weaker or absent in steady coverage districts, and map the pathways from driver to improved supply, demand and coverage. Findings emphasize the critical role of implementation strategies and the need for locally skilled managers that are capable of tailoring strategies to specific settings and community needs. The case studies are unique in their focus on the positive drivers of change and the identification of pathways to coverage improvement, an approach that should be considered in future studies and routine assessments of district-level immunization system performance.

Overview of global, regional, and national routine vaccination coverage trends and growth patterns from 1980 to 2009: implications for vaccine-preventable disease eradication and elimination initiatives

BACKGROUND

Review of the historical growth in annual vaccination coverage across countries and regions can better inform decision makers' development of future goals and strategies to improve routine vaccination services.

METHODS

Using the World Health Organization (WHO) and the United Nations Children's Fund estimates of annual national third dose of diphtheria-tetanus-pertussis-containing vaccine (DTP3) and third dose of polio vaccine (POL3) coverage for 1980-2009, we calculated the mean absolute annual rate of change in national DTP3 coverage among all countries (globally) and among countries within each WHO region, as well as the number of years taken by each region to reach specific regional coverage levels. Last, we assessed differences in mean absolute annual rate of change in DTP3 coverage, stratified by baseline level of DTP3 coverage.

RESULTS

During the 1980s, global DTP3 coverage increased a mean of 5.3 percentage points/year. Annual rate of change decreased to 0.5 percentage points/year in the 1990s and then increased to 0.9 percentage points/year during the 2000s. Mean annual rate of change in coverage across all countries was highest (9.2 percentage points) when national coverage levels were 26%-30% and lowest (-0.9 percentage points) when national coverage levels were 96%-100%. Regional differences existed as both WHO South-East Asia Region and WHO African Region countries experienced mean negative DTP3 coverage growth at lower coverage levels (81%-85%) than other regions. The regions that have achieved 95% DTP3 coverage (Americas, Western Pacific, and European) took 25-29 years to reach that level from a level of 50% DTP3 coverage. POL3 coverage change trends were similar to described DTP3 coverage change trends.

CONCLUSIONS

Mean national coverage growth patterns across all regions are nonlinear as coverage levels increase. Saturation points of mean 0 percentage-point growth in annual coverage varies by region and require further investigation. The achievement of >90% routine coverage is observed to take decades, which has implications for disease eradication and elimination initiatives.

Limitations of using administratively reported immunization data for monitoring routine immunization system performance in Nigeria

BACKGROUND

Efforts are underway to strengthen Nigeria's routine immunization system, yet measuring impact poses a challenge. We document limitations in using administrative data from 12 states in Nigeria and explore alternative approaches.

METHODS

We compared state-reported coverage with the third dose of diphtheria-tetanus-pertussis vaccine (DTP3) to district-reported coverage and data from coverage surveys conducted during 2006-2013. We used district-reported data during 2010-2013 to calculate the annual change in immunization coverage, the percentage of the target population that was unimmunized, and the number of vaccine doses administered. Data quality indicators were also assessed.

RESULTS

State-reported DTP3 coverage was 66%-102% in 2010, 49%-98% in 2011, 38%-84% in 2012, and 75%-123% in 2013 and was a median 46%-114% greater than survey coverage during 2006-2013. The mean local government area (LGA)-reported coverage varied substantially (standard deviation range, 10%-33% across years). For 2010-2013, the mean annual percentage change in LGA-reported DTP3 coverage was -15% from 2010 to 2011, -9% from 2011 to 2012, and 74% from 2012 to 2013; the mean annual percentage change in the percentage of the target population unimmunized was -62%, 426%, and -62%, respectively; and the mean annual percentage change in the number of doses administered was -13%, -7%, and 90%, respectively. Annually, a mean 14% of LGAs reported DTP3 coverage of >100%.

DISCUSSION

Assessing immunization system performance by using administrative data has notable limitations. In addition to long-term improvements in administrative data management, alternatives for measuring routine immunization performance should be considered.