Strategies to increase immunization coverage of tetanus vaccine among women in Sub Saharan Africa: a systematic review

Protective doses of tetanus toxoid immunization and its associated factors among mothers in southern Ethiopia

The World Health Organization recommends tetanus toxoid immunization before or during pregnancy for all women of childbearing age. The goal is to reduce maternal and neonatal mortality due to tetanus. According to the 2016 Ethiopia Demographic and Health Survey (EDHS) report, more than half (51%) of women did not receive protective doses of tetanus immunization. To the best of our knowledge, this study uniquely tried to assess the level of protective doses of tetanus toxoid immunization in southern Ethiopia. A community-based cross-sectional study was conducted among 580 randomly selected participants. Variable with p-value of less than .25 in the bivariate analysis were included in the multivariable logistic regression analysis. Finally, statistical significance was declared at a p-value of less than .05. The proportion of protective doses of tetanus toxoid immunization uptake in the area was found to be 41.9% (95% CI: 38-46%). Being enrolled in formal education [AOR = 6.55, 95% CI: 3.23-9.01], having at least two postnatal care visits [AOR = 3.82; 95% CI: 1.78-6.40], having at least four antenatal care visits [AOR = 2.56; 95% CI: 1.41-4.34], and being visited by Health Extension Workers [AOR = 2.66; 95% CI: 1.42-4.01] were found to be factors enhancing the uptake of protective doses of tetanus toxoid immunization. Generally, the uptake or prevalence of the protective doses of tetanus toxoid immunization in the area was lower than the World Health Organization's target. Therefore, all responsible bodies, including healthcare providers, need to strengthen counseling mothers to enhance the uptake of tetanus toxoid immunization.

Of Money and Men: A Scoping Review to Map Gender Barriers to Immunization Coverage in Low- and Middle-Income Countries

Among the multiple factors impeding equitable childhood immunization coverage in low- and middle-income countries (LMICs), gender barriers stand out as perhaps the most universal. Despite increasing recognition of the importance of gender considerations in immunization programming, there has not yet been a systematic assessment of the evidence on gender barriers to immunization. We conducted a scoping review to fill that gap, identifying 92 articles that described gender barriers to immunization. Studies documented a range of gender influencers across 43 countries in Africa and South Asia. The barrier to immunization coverage most frequently cited in the literature is women's lack of autonomous decision-making. Access to immunization is significantly impacted by women's time poverty; direct costs are also a barrier, particularly when female caregivers rely on family members to cover costs. Challenges with clinic readiness compound female caregiver's time constraints. Some of the most important gender barriers lie outside of the usual purview of immunization programming but other barriers can be addressed with adaptations to vaccination programming. We can only know how important these barriers are with more research that measures the impact of programming on gender barriers to immunization coverage.

Assessment of tetanus Immunization among healthcare workers in Mogadishu, Somalia

Tetanus is still a major problem in sub-Saharan African countries. This study aims to evaluate tetanus disease and vaccine awareness among healthcare workers in Mogadishu. This descriptive, cross-sectional study was scheduled for January 2-7, 2022. A questionnaire consisting of 28 questions was applied in a face-to-face manner to 418 healthcare workers. Only health workers aged≥18 living in Mogadishu were included. Questions about sociodemographic characteristics, tetanus disease, and vaccines were developed. 71.1% of the participants were female, 72% were ˂25 years old, 42.6% were nursing students, and 63.2% had a university education. It was observed that 46.9% of the volunteers had an income level of <$250, and 60.8% resided in the city center. 50.5% of the participants received a tetanus vaccine in their childhood. Questions to determine participants' level of knowledge about tetanus and the tetanus vaccine were responded to with an accuracy of between 44 and 77%. Although 38.5% of the participants reported that they were exposed to trauma at least once a day, the rate of those who had three or more doses of the vaccine was only 10.8%. On the other hand, 51.4% reported that they had received training about tetanus and vaccination. There was a significant difference (p < .001) in terms of knowledge level among sociodemographic characteristics. The fear of side effects was the most important reason for not being vaccinated. Healthcare workers in Mogadishu have little awareness of tetanus disease and vaccines. Efforts to improve education and other factors will be sufficient to eliminate the disadvantage brought about by the socio-demographic structure.

Inequalities in Immunization against Maternal and Neonatal Tetanus: A Cross-Sectional Analysis of Protection at Birth Coverage Using Household Health Survey Data from 76 Countries

Substantial progress in maternal and neonatal tetanus elimination has been made in the past 40 years, with dramatic reductions in neonatal tetanus incidence and mortality. However, twelve countries have still not achieved maternal and neonatal tetanus elimination, and many countries that have achieved elimination do not meet key sustainability thresholds to ensure long-lasting elimination. As maternal and neonatal tetanus is a vaccine-preventable disease (with coverage of the infant conferred by maternal immunization during and prior to pregnancy), maternal tetanus immunization coverage is a key metric for monitoring progress towards, equity in, and sustainability of tetanus elimination. In this study, we examine inequalities in tetanus protection at birth, a measure of maternal immunization coverage, across 76 countries and four dimensions of inequality via disaggregated data and summary measures of inequality. We find that substantial inequalities in coverage exist for wealth (with lower coverage among poorer wealth quintiles), maternal age (with lower coverage among younger mothers), maternal education (with lower coverage among less educated mothers), and place of residence (with lower coverage in rural areas). Inequalities existed for all dimensions across low- and lower-middle-income countries, and across maternal education and place of residence across upper-middle-income countries. Though global coverage changed little over the time period 2001-2020, this obscured substantial heterogeneity across countries. Notably, several countries had substantial increases in coverage accompanied by decreases in inequality, highlighting the need for equity considerations in maternal and neonatal tetanus elimination and sustainability efforts.

Resource mobilization for tetanus vaccination in Vietnam: Uptake, demand and willingness to pay among women of reproductive age

Introduction

Tetanus vaccine coverage in Vietnam has been declining in recent years due to a rapid population growth rate, shrinking budget, and inefficient resource mobilization strategy. This study examined the uptake, demand, and willingness to pay (WTP) for tetanus vaccines in Vietnamese women of reproductive age as well as determined associated factors and assessed the feasibility of the long-term tetanus vaccine resource mobilization scheme.

Methods

Cross-sectional data were obtained on 807 women of childbearing age in Hanoi, Vietnam in 2016. Tetanus vaccine uptake, demand, and willingness to pay were collected by using a structured questionnaire. Multivariable logistic and interval regression models were used to examine associated factors with vaccine uptake, demand, and WTP.

Results

Of 807 participants, 42.4 and 64.8% had sufficient tetanus vaccination (i.e., received at least three doses of vaccine) and were willing to pay for tetanus vaccination. The mean amount of WTP for one dose of tetanus was US$ 7.3 (95% CI = 6.7-7.9). Having children or being aware that the tetanus vaccine was free-of-charge were negatively associated with WTP for tetanus vaccine. Having a high school education, living in a rural area, and not being aware of vaccine prices or being aware that vaccines were provided freely reduced the amount of WTP. WTP increased among women receiving information from friends and relatives.

Conclusion

Despite of exemption from the tetanus vaccination programs, this study indicated a low tetanus vaccination coverage and a moderate degree of WTP for tetanus vaccine among Vietnamese women of childbearing age. Target-specific educational and financial support interventions, along with efforts to reduce vaccination costs are critical to improving the vaccine uptake, demand, and WTP for tetanus immunization among women.

Individual and community-level determinants of poor tetanus toxoid immunization among pregnant women in Ethiopia using data from 2016 Ethiopian demographic and health survey; multilevel analysis

Background

Tetanus is a vaccine-preventable disease that can occur in all populations, with neonates and pregnant women being at the most risk. Ethiopia has the highest maternal and neonatal tetanus morbidity and mortality rates. Besides, only 49% of mothers get vaccinated with adequate tetanus toxoid in Ethiopia which is below the world health organization recommendation. To date, there is limited evidence on the individual and community level determinants of poor tetanus toxoid (TT) immunization. Therefore, this study aimed to assess individual and community-level factors associated with poor TT immunization coverage in Ethiopia.

Method

Secondary data analysis was conducted using the 2016 Ethiopian demographic and health survey. A total of 7043 pregnant women were included in the current study. A multilevel logistic regression model was used to identify individual and community level determinants of poor tetanus toxoid immunization. Finally, the adjusted odds ratio with a 95% confidence interval was reported.

Results

In the multilevel logistic regression model adjustment, having no Antenatal care visit (AOR = 5.64; 95% CI:2.48,7.30) and having one to three antenatal care visit (AOR = 1.50; 95% CI: 1.19–1.82); poor wealth index (AOR = 1.26; 95% CI: 1.03, 1.54); not being exposed to media (AOR = 1.29; 95% CI: 1.10, 1.51); maternal unemployment (AOR = 1.15; 95% CI: 1.10, 1.31); rural residence (AOR = 1.13; 95% CI: 1.08, 1.72); and high community illiteracy (AOR = 1.28; 95% CI: 1.03, 1.58) were associated with higher odds of poor tetanus toxoid immunization. Whereas, iron uptake during pregnancy (AOR = 0.59; 95% CI: 0.51, 0.68), was associated with lower odds of poor tetanus toxoid immunization.

Conclusion

In this study tetanus toxoid (TT) vaccine utilization was affected by both community and individual-level factors. Therefore, focusing on antenatal care services especially encouraging pregnant women to have at least four visits, consulting women to be exposed to media, improving community literacy and maternal employment will help to minimize TT underutilization.

Drivers and barriers of vaccine acceptance among pregnant women in Kenya

Maternal vaccination coverage remains suboptimal globally and is lowest in low- and middle-income countries. Attitudes toward maternal vaccines have been characterized in middle-high income settings, however data from African countries are limited. We assessed drivers and barriers of vaccine acceptance among pregnant women in Kenya. We conducted a cross-sectional survey among pregnant women aged 15-49 y. We enrolled a convenience sample of women presenting for antenatal care at seven health-care facilities in four diverse counties (Nairobi, Mombasa, Marsabit, Siaya) of Kenya and from the community in two counties (Nairobi, Siaya). We described frequencies of socio-demographic characteristics of participants and their knowledge, attitudes, and beliefs regarding maternal vaccination. We enrolled 604 pregnant women with a median age of 26.5 y, of whom 48.2% had primary education or less. More than 95% agreed that maternal vaccines are "important for my health" and that getting vaccinated is "a good way to protect myself from disease". The most commonly cited reason in favor of maternal vaccination was disease prevention (53.2%). Fear of side effects to mother/baby (15.1%) was the most frequently reported potential barrier. Influenza vaccine is not in routine use in Kenya; however, 77.8% reported willingness to accept influenza vaccination during pregnancy. Maternal vaccination is well accepted among Kenyan pregnant women. We identified the provision of adequate vaccine information and addressing safety concerns as opportunities to improve maternal vaccine uptake. The expressed willingness to receive a vaccine not currently in routine use bodes well for implementation of new maternal vaccines in Kenya.

Impact of Helminth Infections during Pregnancy on Vaccine Immunogenicity in Gabonese Infants

Helminth infections are common in sub-Saharan Africa. Besides direct clinical effects, a bias towards a T helper type 2 (Th2) cell immune response is observed. The consequences of parasite infection during pregnancy for the mother and particularly for the fetus and the newborn can be severe and may include impaired immune response during acute infection and vaccination. Here, we present data of immune responses to vaccines given within the expanded program on immunization (EPI) of infants born to helminth infected or non-infected mothers. The study was conducted in Lambaréné and surroundings, Gabon. Maternal helminth infection was diagnosed microscopically using the Kato-Katz method for soil-transmitted helminths (STH), urine filtration for Schistosoma haematobium infections and the saponin-based method for filarial infections. Plasma antibody levels to different vaccine antigens were measured in mothers and their offspring by enzyme-linked immunosorbent assay (ELISA) at different timepoints. We found 42.3% of the mothers to be infected with at least one helminth species. Significantly lower anti-tetanus toxoid immunoglobulin (Ig) G was detected in the cord blood of infants born to helminth infected mothers. Following vaccination, immune responses of the infants to EPI vaccines were similar between the two groups at nine and 12 months. Even though infection with helminths is still common in pregnant women in Gabon, in our setting, there was no evidence seen for a substantial effect on infants’ immune responses to vaccines given as part of the EPI.

The role of the single interchains disulfide bond in tetanus and botulinum neurotoxins and the development of antitetanus and antibotulism drugs

A large number of bacterial toxins consist of active and cell binding protomers linked by an interchain disulfide bridge. The largest family of such disulfide-bridged exotoxins is that of the clostridial neurotoxins that consist of two chains and comprise the tetanus neurotoxins causing tetanus and the botulinum neurotoxins causing botulism. Reduction of the interchain disulfide abolishes toxicity, and we discuss the experiments that revealed the role of this structural element in neuronal intoxication. The redox couple thioredoxin reductase-thioredoxin (TrxR-Trx) was identified as the responsible for reduction of this disulfide occurring on the cytosolic surface of synaptic vesicles. We then discuss the very relevant finding that drugs that inhibit TrxR-Trx also prevent botulism. On this basis, we propose that ebselen and PX-12, two TrxR-Trx specific drugs previously used in clinical trials in humans, satisfy all the requirements for clinical tests aiming at evaluating their capacity to effectively counteract human and animal botulism arising from intestinal toxaemias such as infant botulism.