Predictors of Infant Hepatitis B Immunization in Cameroon: Data to Inform Implementation of a Hepatitis B Birth Dose

Timeliness of routine childhood vaccination in 103 low-and middle-income countries, 1978-2021: A scoping review to map measurement and methodological gaps

Empiric studies exploring the timeliness of routine vaccination in low-and middle-income countries (LMICs) have gained momentum in the last decade. Nevertheless, there is emerging evidence suggesting that these studies have key measurement and methodological gaps that limit their comparability and utility. Hence, there is a need to identify, and document these gaps which could inform the design, conduct, and reporting of future research on the timeliness of vaccination. We synthesised the literature to determine the methodological and measurement gaps in the assessment of vaccination timeliness in LMICs. We searched five electronic databases for peer-reviewed articles in English and French that evaluated vaccination timeliness in LMICs, and were published between 01 January 1978, and 01 July 2021. Two reviewers independently screened titles and abstracts and reviewed full texts of relevant articles, following the guidance framework for scoping reviews by the Joanna Briggs Institute. From the 4263 titles identified, we included 224 articles from 103 countries. China (40), India (27), and Kenya (23) had the highest number of publications respectively. Of the three domains of timeliness, the most studied domain was 'delayed vaccination' [99.5% (223/224)], followed by 'early vaccination' [21.9% (49/224)], and 'untimely interval vaccination' [9% (20/224)]. Definitions for early (seven different definitions), untimely interval (four different definitions), and delayed vaccination (19 different definitions) varied across the studies. Most studies [72.3% (166/224)] operationalised vaccination timeliness as a categorical variable, compared to only 9.8% (22/224) of studies that operationalised timeliness as continuous variables. A large proportion of studies [47.8% (107/224)] excluded the data of children with no written vaccination records irrespective of caregivers' recall of their vaccination status. Our findings show that studies on vaccination timeliness in LMICs has measurement and methodological gaps. We recommend the development and implement of guidelines for measuring and reporting vaccination timeliness to bridge these gaps.

mHealth Phone Intervention to Reduce Maternal Deaths and Morbidity in Cameroon: Protocol for Translational Adaptation

Purpose

The purpose of this NIH-funded protocol is to adapt (Aim 1) and pilot test (Aim 2) an mHealth intervention to improve maternal and child health in Cameroon. We will adapt the 24/7 University of Alabama at Birmingham Medical Information Service via Telephone (MIST) provider support system to mMIST (mobile MIST) for peripheral providers who provide healthcare to pregnant and postpartum women and newborns in Cameroon.

Methods

In Aim 1, we apply qualitative and participatory methods (in-depth interviews and focus groups with key stakeholders) to inform the adaptation of mMIST for use in Cameroon. We use the sequential phases of the ADAPT-ITT framework to iteratively adapt mMIST incorporating qualitative findings and tailoring for local contexts. In Aim 2, we test the adapted intervention for feasibility and acceptability in Ndop, Cameroon.

Results

This study is ongoing at the time that this protocol is published.

Conclusion

The adaptation, refinement, and pilot testing of mMIST will be used to inform a larger-scale stepped wedged cluster randomized controlled effectiveness trial. If successful, this mHealth intervention could be a powerful tool enabling providers in low-resource settings to deliver improved pregnancy care, thereby reducing maternal and fetal deaths.

Hepatitis B birth dose vaccination for newborns in Uganda: A qualitative inquiry on pregnant women's perceptions, barriers and preferences

BACKGROUND

Sub-Saharan Africa continues with very low hepatitis B (HBV) birth dose vaccination coverage. To guide policy on HBV vaccine for newborns, we explored perceptions, barriers and preferences of pregnant women regarding HBV and the HBV birth dose vaccination.

METHODS

We conducted eight focus groups discussions (FGDs) among 70 pregnant women, stratified by rural-urban residence, age and education level, using a structured focus group discussion guide to explore birth dose awareness, perceptions, barriers and preferences. Data were transcribed, coded and analysed using framework analysis.

RESULTS

Perceptions related to HBV and liver cancer causes and prevention were diverse; most FGD participants did not perceive illnesses as distinctly different. Older women-groups, both urban and rural, had never heard about HBV, but were aware of liver cancer, viewing the disease as fatal. No FGD participants were aware of HBV birth dose. Concerns included vaccine safety, its availability to women who deliver outside the health system and mistrust in health-care worker (HCWs) when handling newborns. Rural-dwelling groups perceived absence of HBV services, while FGDs with young participants believed vaccine side-effects hampered birth dose planning. Most women-groups preferred (i) oral to injectable vaccines; (ii) receiving birth dose education during antenatal, to media-based education; (iii) that newborns receive the birth dose immediately after delivery in the mother's presence.

CONCLUSION

Although the birth dose is acceptable among pregnant women, planners need to continuously engage them as key stakeholders during planning to address concerns, in order to raise confidence, maximize uptake and strengthen HBV eradication efforts.

Hepatitis B Vaccination in Senegalese Children: Coverage, Timeliness, and Sociodemographic Determinants of Non-Adherence to Immunisation Schedules (ANRS 12356 AmBASS Survey)

Detailed knowledge about hepatitis B virus (HBV) vaccination coverage and timeliness for sub-Saharan Africa is scarce. We used data from a community-based cross-sectional survey conducted in 2018–2019 in the area of Niakhar, Senegal, to estimate coverage, timeliness, and factors associated with non-adherence to the World Health Organisation-recommended vaccination schedules in children born in 2016 (year of the birth dose (BD) introduction in Senegal) and 2017–2018. Vaccination status was assessed from vaccination cards, surveillance data, and healthcare post vaccination records. Among 241 children with available data, for 2016 and 2017–2018, respectively, 31.0% and 66.8% received the BD within 24 h of birth (BD schedule), and 24.3% and 53.7% received the BD plus at least two pentavalent vaccine doses within the recommended timeframes (three-dose schedule). In logistic regression models, home birth, dry season birth, and birth in 2016 were all associated with non-adherence to the recommended BD and three-dose schedules. Living over three kilometres from the nearest healthcare post, being the firstborn, and living in an agriculturally poorer household were only associated with non-adherence to the three-dose schedule. The substantial proportion of children not vaccinated according to recommended schedules highlights the importance of considering vaccination timeliness when evaluating vaccination programme effectiveness. Outreach vaccination activities and incentives to bring children born at home to healthcare facilities within 24 h of birth, must be strengthened to improve timely HBV vaccination.

Characterization of immunization secondary analyses using demographic and health surveys (DHS) and multiple indicator cluster surveys (MICS), 2006-2018

BACKGROUND

Infant immunization coverage worldwide has plateaued at about 85%. Using existing survey data to conduct analyses beyond estimating coverage may help immunization programmes better tailor strategies to reach un- and under-immunized children. The Demographic and Health Survey (DHS) and the Multiple Indicators Cluster Survey (MICS), routinely conducted in low and middle-income countries (LMICs), collect immunization data, yet vaccination coverage is often the only indicator reported and used. We conducted a review of published immunization-related analyses to characterize and quantify immunization secondary analyses done using DHS and MICS databases.

METHODS

We conducted a systematic search of the literature, of immunization-related secondary analyses from DHS or MICS published between 2006 and August 2018. We searched 15 electronic databases without language restrictions. For the articles included, relevant information was extracted and analyzed to summarize the characteristics of immunization-related secondary analyses. Results are presented following the PRISMA guidelines.

RESULTS

Among 1411 papers identified, 115 met our eligibility criteria; additionally, one article was supplemented by the Pan American Health Organization. The majority were published since 2012 (77.6%), and most (68.9%) had a first or corresponding author affiliated with institutions in high-income countries (as opposed to LMICs where these surveys are conducted). The median delay between survey implementation and publication of the secondary analysis was 5.4 years, with papers with authors affiliated to institutions in LMIC having a longer median publication delay (p < 0.001). Over 80% of the published analyses looked at factors associated with a specific vaccine or with full immunization. Quality proxies, such as reporting percent of immunization data from cards vs recall; occurrence and handling of missing data; whether survey analyses were weighted; and listing of potential biases or limitations of the original survey or analyses, were infrequently mentioned.

CONCLUSION

Our review suggests that more needs to be done to increase the increase the utilization of existing DHS and MICS datasets and improve the quality of the analyses to inform immunization programmes. This would include increasing the proportion of analyses done in LMICs, reducing the time lag between survey implementation and publication of additional analyses, and including more qualitative information about the survey in the publications to better interpret the results.

Social and behavioral determinants of attitudes towards and practices of hepatitis B vaccine birth dose in Vietnam

BACKGROUND

Hepatitis B virus (HBV) infection is a significant public health issue in Vietnam. Our goal was to understand the determinants of attitudes towards and practices of hepatitis B vaccine birth dose (HepB-BD) in certain regions of Vietnam.

METHOD

A rapid qualitative assessment was conducted in three geographically diverse provinces that reported low coverage (<50%) of HepB-BD. Using purposive sampling of participants, 29 focus group discussions and 20 in-depth interviews were held with caregivers (n = 96), healthcare providers (n = 75), and healthcare administrators (n = 16). Summary notes from these were translated, and inductive coding was used to derive themes. The SAGE Vaccine Hesitancy Determinants Matrix was used as a theoretical framework to organize barriers and facilitators associated with the themes into three levels of influence.

RESULTS

At the individual and group level, caregivers who had higher levels of knowledge about HepB-BD sought the vaccine proactively, while others with lower knowledge faced barriers to the vaccine. Some caregivers reported a negative attitude toward health services because of a language barrier or had generalized concerns about HepB-BD due to media reporting of the past adverse events. Distress arising from potential adverse events was equally common among healthcare providers. At the contextual level, the physical environment made it difficult for caregivers to access healthcare facilities and for providers to conduct outreach. Home births posed a challenge for timely administration of HepB-BD, while health facility births facilitated it. Vaccination-specific barriers included misinterpretation of pre-vaccination screening criteria and asking for the consent of caregivers. Inadequate resources for service delivery negatively influenced HepB-BD attitudes and practices.

CONCLUSION

Given the diversity of barriers associated with attitudes towards and practices of HepB-BD in the three provinces, tailored interventions will be necessary for both demand- and supply-side factors. Rural areas, often with more home births and geographic barriers, may require focused attention.

Global dynamics of a model of hepatitis B virus infection in a sub-Saharan African rural area

We formulate and systematically study a deterministic compartmental model of Hepatitis B. This model has some important and novel features compared with the well-known basic model in the literature. Specifically, it takes into account the differential susceptibility that follows the vaccine formulation employing three-doses schedule. It points up the HbeAg status of carriers, their levels of viral replication, the fact that treatment being not curative is recommended only to a small proportion of chronic carriers, and finally the fact that only inactive carriers are able to recover from disease. The model has simple dynamical behavior which has a globally asymptotically stable disease-free equilibrium when the basic reproduction number [Formula: see text] and an endemic equilibrium when [Formula: see text]. By the use of Lyapunov functions, when it exists, we prove the global asymptotic stability of the endemic equilibrium under some conditions. Using data from Tokombere, a rural area in Cameroon, numerical simulations are performed. These numerical simulations first confirm analytical results, second they suggest that a policy based on treatment could not significantly impact the course of the infection. Third, they show as it is well known that vaccination is a very effective measure to control the infection. Furthermore, they show that neonatal vaccination influences more the course of infection than mass vaccination strategy. Nevertheless, they picture how much loss between consecutive doses of vaccine could be harmful. Finally, it is suggested that for a Sub-saharan African rural area, two-thirds of expected incidence of Hepatitis B virus infection and one third of expected prevalence of chronic carriers could be averted by 2030 if the birth dose vaccination becomes systematic and if mass vaccination rate increases to up 10%.

Elimination of Vertical Transmission of Hepatitis B in Africa: A Review of Available Tools and New Opportunities

PURPOSE

This review article focuses on preventing vertical transmission of hepatitis B virus (HBV) among pregnant women living in sub-Saharan Africa (SSA), where disease is endemic and the estimated maternal HBV seroprevalence is >8%. Available interventions that have been studied in low- and middle-income countries are compared in terms of efficacy and effectiveness in clinical practice. Global disease-elimination targets, barriers to HBV-prevention efforts, and critical research gaps are discussed.

METHODS

A PubMed literature search in February 2018 identified relevant studies of interventions to reduce or prevent the transmission of HBV during pregnancy or in the peripartum period. Studies that focused on interventions that are currently available or could be made available in SSA were included. Trials conducted in SSA and other low-income countries were prioritized, although studies of interventions in middle- and high-income countries were included.

FINDINGS

Among 127 studies and reports included in the review, 60 included data from SSA. The most cost-effective intervention to reduce HBV infection rates in SSA is timely birth-dose vaccination followed by completion of the 3-dose infant-vaccination series. The identification and treatment of pregnant women with elevated HBV viral load to further reduce the risk for vertical transmission in SSA show promise, but efficacy and tolerability trials in Africa are lacking.

IMPLICATIONS

Scale-up of currently available tools is required to reach HBV disease-elimination goals in SSA. Many countries in SSA are in the process of rolling out national birth-dose vaccination campaigns; this roll out provides an opportunity to evaluate and improve processes in order to expand coverage. Early antenatal care, promotion of facility deliveries, and increased awareness of HBV prevention are also key components of prevention success. Future studies in SSA should identity an HBV-prevention package that is effective, well tolerated, and feasible and can be administered in the antenatal clinic and tailored to vertical-transmission risk.