From current vaccine recommendations to everyday practices: An analysis in five sub-Saharan African countries

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.

Women's Empowerment and Children's Complete Vaccination in the Democratic Republic of the Congo: A Cross-Sectional Analysis

(1) Background: The empowerment of women contributes to better child health and wellness. This study aimed to examine the association between women’s empowerment and complete vaccination of children, as recommended in the National Expanded Program on Immunization (EPI) in the Democratic Republic of the Congo (DRC). (2) Methods: In this cross-sectional study, a principal component analysis (PCA) was conducted on data from the Multiple-Indicator Cluster Survey 6 (MICS-6) to determine the dimensions of women’s empowerment. Logistic regression analysis was used to assess the association between women’s empowerment and complete vaccination of children stratified by household wealth. In total, 3524 women with children aged 12–23 months were included in the study. (3) Results: Women’s empowerment was defined by three dimensions, namely intrinsic agency, enabling resources, and social independence. Children of women with high levels of empowerment had higher odds of complete vaccination, with values of 1.63 (p = 0.002) and 1.59 (p = 0.012) for intrinsic agency and enabling resources of the empowerment, respectively, compared to the children of women with low levels of empowerment; however, social independence failed to be associated with the vaccination status of children. After stratification by household wealth, the OR of complete vaccination was higher in women from middle-income households with high levels of intrinsic agency (OR: 2.35, p = 0.021) compared to women from poor households with high levels of intrinsic agency (OR: 1.92, p = 0.004). (4) Conclusions: Higher levels of women’s empowerment, especially intrinsic agency and enabling resources, were associated with complete vaccination in children in the DRC. Household wealth status influenced the associations. The empowerment of women is crucial in promoting the complete vaccination of children and providing equal access to vaccines.

Magnitude and associated factors of delayed vaccination among children aged 11-23 months in, Tigray, Ethiopia, 2018

BACKGROUND

Delay in receiving the vaccination is a major public health problem that has been associated with vaccine-preventable disease epidemics. In Ethiopia, many children have not received the benefits of age-appropriate vaccination; thus more than 90% of child deaths are largely due to preventable communicable diseases.

OBJECTIVE

The present study assessed the magnitude and associated factors of delayed vaccination among 12-23 months old children in Tigray, Ethiopia.

METHODS

A community-based cross-sectional study was carried out among 393, 12-23 months old children from July 1 to 30, 2018. Data were collected using a structured interviewer-administered questionnaire. The questionnaire includes socio-demographic, economic factors, Maternal/caregiver factors, Child's factors, and Service-related factors. We applied bivariable and multivariable logistic regression to determine predictors for delayed Vaccination. The odds ratio with 95% CI was computed to evaluate the strength of the association.

RESULTS

393 participants were involved in the study. The magnitude of delayed vaccination was 29.5% (95% CI 26.7-45). Mothers who attend tertiary (University/college) education (AOR 0.169, 95% CI 0.032-0.882), and secondary education (AOR 0.269, 95% CI 0.114-0.636) had the protective effect of delayed vaccination. But the sickness of a child (AOR = 11.8, 95% CI 6.16-22.65) was a risk for delayed vaccination.

CONCLUSIONS

The magnitude of delayed vaccination was high, particularly among participants with Mother's education, and Mother's consideration in the child's wellness to take the vaccine. This implies that it is important to give emphasis, especially for the mothers who have an uneducated and sick child to increase awareness about the advantage of vaccination, which will improve on-time vaccination.

Age-appropriate vaccination practice and associated factors among mothers of children aged less than one year in the pastoral community of Afar region, Ethiopia

Achieving and maintaining high-level immunization coverage is the priority of the health-care delivery system. However, any delay in receiving the vaccine leaves youngsters inadequately protected. Timely vaccination has scarcely been reported and given little attention in developing nations like Ethiopia, which hinders effective interventions. Therefore, this study aimed to assess age-appropriate vaccination practice and associated factors among mothers of children aged less than one year in the pastoral community. A community-based cross-sectional study has conducted among 340 mothers/caregivers of children aged less than one year in Samara-logia city administration. A systematic random sampling technique was employed to identify and enroll mothers-child paired. The logistic regression analysis had done to identify the factors associated with age-appropriate vaccination practice. The statistical association had measured, and a p-value < 0.05 was considered statistically significant. In this study, a total of 331 mothers/caregivers-child pairs participated with a response rate of 97.3%. The age-appropriate vaccination practice was 43.7% (95% CI, 38%, 49.5%). Mothers who had higher educational level (Adjusted odds ratio (AOR)) = AOR = 2.89, 95% CI (1.14, 7.3), antenatal care follow-up (AOR = 2.1, 95% CI (1.04, 4.1)), and had good knowledge on vaccination (AOR = 3.1, 95% CI (1.4, 6.78)) were associated with increased odds of age-appropriate vaccination practice.

Age-appropriate vaccination coverage and its determinants for the polio containing vaccine 1-3 and measles-containing vaccine doses in Zhejiang province, China: A community-based cross-sectional study

Background: This study aimed to evaluate the age-appropriate coverage and its associated risk factors for the primary vaccination of Polio containing vaccine (PCV) and measles-containing vaccine (MCV) through the secondary use of the 2018 Zhejiang provincial coverage survey among children aged 12-23 months. Methods: Data were collected through structured pre-tested Chinese version questionnaire by face-to-face interview among 770 mothers whose children aged 12-23 months. Age-appropriate vaccination coverage was measured using Chinese vaccination schedule recommendation. Bivariate and multivariate logistic regression models were adopted to identify determinants of the age-inappropriate vaccination. Results: The age-appropriate vaccination coverage of PCV1, PCV2, PCV3, and MCV was 88.8%, 80.8%, 73.6%, and 75.7%, respectively. The risk factors associated with the age-inappropriate vaccination of PCV 1-3 dose and MCV included child's gender, birthplace, living area, maternal education level, immigration status, monthly household income, participation of the pregnant women's seminar, antenatal care follow-up, knowledge on vaccination. Conclusion: The proportions of age-appropriate vaccination coverage were low compared with the up-to-date coverage. Modifiable factors were associated with age-inappropriate vaccinations. Vaccination interventions should consider identified modifiable factors to improve age-appropriate vaccination coverage.

Age-appropriate vaccination coverage and its associated factors for pentavalent 1-3 and measles vaccine doses, in northeast Ethiopia: A community-based cross-sectional study

BACKGROUND

In Ethiopia, there are limited studies on age-appropriate vaccinations that children received at the recommended specific ages. Therefore, we assessed age-appropriate vaccinations coverage and its associated factors among children 12 to 23 months of age in Menz Lalo district, northeast Ethiopia.

METHODS

A community-based cross-sectional study was conducted in Menz Lalo district from March to April/2018 among 417 mothers/caregivers with children 12 to 23 months of age using simple random sampling technique. Data were collected using a pretested structured questionnaire. Information about children's vaccination status was collected from vaccination cards. Age-appropriate vaccination coverage was measured using World Health Organization vaccination schedule recommendation. Data was entered into Epi-Info7 software and exported to SPSS-20 for analysis. Four consecutive logistic regression models were performed to identify factors associated with age-inappropriate vaccinations. A P-value of ≤ 0.05 was considered to state statistically significant associations.

RESULTS

Age-appropriate vaccination coverage was 39.1% (95% CI: 34.3 to 44) for pentavalent 1, 36.3% (95% CI: 31.6 to 41.5) for pentavalent 2, 30.3% (95% CI: 25.6 to 35) for pentavalent 3 and 26.4% (95% CI: 21.7 to 31) for measles vaccine doses. Age-inappropriate pentavalent 1-3 vaccinations was associated with being male sex (AOR: 0.47, 95% CI: 0.29-0.74), lack of telephone (AOR: 2.2, 95% CI: 1.4-3.6), lack of usual caretaker (AOR: 2.6, 95% CI: 1.3-5.2), unplanned pregnancy (AOR: 1.9, 95% CI: 1.1-3.5), missing pregnant women's conference (AOR: 2.7, 95% CI: 1.3-5.7), decreasing birth order (AOR: 0.34, 95% CI: 0.17-0.68) and insufficient knowledge (AOR: 2.7, 95% CI: 1.6-4.4).

CONCLUSION

The proportions of age-appropriate vaccination coverage were low in the study area. Modifiable factors were associated with age-inappropriate vaccinations. Vaccination interventions should consider identified modifiable factors to improve age-appropriate vaccinations coverage.

Impact of vaccination delay on deaths averted by pneumococcal conjugate vaccine: Modeled effects in 8 country scenarios

Delay in vaccination from schedule has been frequently documented and varies by vaccine, dose, and setting. Vaccination delay may result in the failure to prevent deaths that would have been averted by on-schedule vaccination.

We constructed a model to assess the impact of delay in vaccination with pneumococcal conjugate vaccine (PCV) on under-five mortality. The model accounted for the week of age-specific risk of pneumococcal mortality, direct effect of vaccination, and herd protection. For each model run, a cohort of children were exposed to the risk of mortality and protective effect of PCV for each week of age from birth to age five. The model was run with and without vaccination delay and difference in number of deaths averted was calculated. We applied the model to eight country-specific vaccination scenarios, reflecting variations in observed vaccination delay, PCV coverage, herd effect, mortality risk, and vaccination schedule. As PCV is currently being scaled up in India, we additionally evaluated the impact of vaccination delay in India under various delay scenarios and coverage levels.

We found deaths averted by PCV with and without delay to be comparable in all of the country scenarios when accounting for herd protection. In India, the greatest relative difference in deaths averted was observed at low coverage levels and greatest absolute difference was observed around 60% vaccination coverage. Under moderate delay scenarios, vaccination delay had modest impact on deaths averted by PCV in India across levels of coverage or vaccination schedule. Without accounting for herd protection, vaccination delay resulted in much greater failure to avert deaths.

Our model suggests that realistic vaccination delay has a minimal impact on the number of deaths averted by PCV when accounting for herd effect. High population coverage can largely over-ride the deleterious effect of vaccination delay through herd protection.

Vaccination timeliness and delay in low- and middle-income countries: a systematic review of the literature, 2007-2017

Background: Traditional measurements of vaccine coverage at specific ages can mask poor vaccine timeliness. However, optimal measurement of timing is unclear due to variations in countries’ recommended vaccination schedules and lack of a commonly accepted standard for “timeliness”. We conducted a systematic review of literature on vaccine timeliness and delay in low- and middle-income countries from 2007 to 2017.

Methods: A search of articles published between January 1 2007 and December 31 2017, was performed in PubMed, EBSCOhost, and Embase.

Results: 67 papers were included, of which 83% used a categorical measure of delay and 41% evaluated continuous delay. The most common age at assessment was 1 month, with earlier age benchmarks typically used with birth doses.

Conclusions: Categorical definitions of vaccination timing vary widely, with benchmarks of delay varying from days to weeks to months. Use of a continuous measure of vaccine delay may be more informative and comparable.

Childhood vaccination in Kenya: socioeconomic determinants and disparities among the Somali ethnic community

OBJECTIVES

Kenya has a significant refugee population, including large numbers of Somali migrants. This study examines the vaccination status of Kenyan children and sociodemographic predictors of vaccination, including Somali ethnicity.

METHODS

Using the 2014 Kenyan Demographic and Health Survey, we calculated the proportion of non-vaccinated, under-vaccinated, and fully vaccinated children, defining full vaccination as one dose Bacille Calmette-Guerin, three doses polio, three doses pentavalent, and one dose measles. We assessed associations among various factors and vaccination status using multinomial logistic regression and explored the effect of Somali ethnicity through interaction analysis.

RESULTS

The study sample comprised 4052 children aged 12-23 months, with 79.4% fully, 19.0% under-, and 1.6% non-vaccinated. Among Somalis, 61.9% were fully, 28.7% under-, and 9.4% non-vaccinated. Somalis had significantly greater odds of under- and non-vaccination than the Kikuyu ethnic group. Wealth and birth setting were associated with immunization status for Somalis and non-Somalis.

CONCLUSIONS

Disparities persist in pediatric vaccinations in Kenya, with Somali children more likely than non-Somalis to be under-vaccinated. Health inequalities among migrants and ethnic communities in Kenya should be addressed.