Diphtheria-tetanus-pertussis Research Articles

Diphtheria-tetanus-pertussis vaccine mortality

Although the diphtheria-tetanus-pertussis (DTP) vaccine is lifesaving through decades, it has been voiced that the vaccine is associated with 50% increase in mortality, an alleged negative non-specific vaccine effect prone to girls. Post hoc analyses of historical observational data supporting the hypothesis of the DTP vaccine having detrimental effects have never been replicated in low- or high-income countries. An RCT in Guinea-Bissau found fewer deaths with DTP vaccine than without. The hypothesis seems further rejected by the overall decline over time in child mortality in both girls and boys.

Vaccination coverage of persons using hospital outpatient mental health services at Heraklion, Crete, Greece: A cross-sectional study during pandemic.

Persons with mental health disorders are vulnerable, with demanding care needs. This cross-sectional study aimed to report on their vaccination coverage against COVID-19 and common vaccine-preventable diseases. The study was conducted from September to November 2022 at the psychiatric outpatient settings of Venizeleion General Hospital of Heraklion, Crete, Greece, and the Mental Health Center of Heraklion. Information was collected via personal medical interview and prescription data. The study population included 361 participants, with a mean age of 49.8±14.3 years, 59.0% women. The most common diagnoses were recurrent depressive disorder (24.1%), schizophrenia (22.7%), anxiety disorder (21.3%), and bipolar disorder (15.7%). Vaccination coverage against seasonal influenza for 2020, 2021, and 2022 was 43.2%, 39.8%, and 40.7%, respectively. Pneumococcal vaccination included the conjugate (28.8%) and polysaccharide (7.7%) vaccines. Vaccination against Tetanus, Diphtheria, Pertussis (TDP) accounted for 11.0%, Hepatitis B for 5.8%, and Herpes Zoster for 27.1%. COVID-19 vaccination, with at least one booster dose, reached a high 73.6%. Patients with severe mental illness, 139 out of 361, were less likely to have contracted COVID-19 (50/139, 35.9%) than those without (108/222, 46.6%), (p=0.018). Coverage with polysaccharide vaccine, TDP, and Hepatitis B, was very low. Patients annually vaccinated for influenza in the last three consecutive years were most likely to be fully vaccinated for pneumococcal disease and for COVID-19 (with at least one booster dose). Future research and clinical practice should focus on identifying patients at risk of not receiving preventive services, such as vaccines.

Trends of Diphtheria–Tetanus–Pertussis and Measles Vaccine Coverage Preceding and during the COVID-19 Pandemic: An Analysis of the WHO European Region from 2000 to 2022

Available data highlights the significant impact of the COVID-19 pandemic on global vaccination trends. Despite this, comprehensive evaluations of these changes at the European level are still scarce. This study examines coverage for diphtheria, tetanus, and pertussis (DTP) and measles-containing vaccines (MCV) in the WHO European Region from 2000 to 2022. Vaccination coverage data, defined as the percentage of surviving infants who received the first and third doses of DTP (DTP1 and DTP3) and the first and second doses of MCV (MCV1 and MCV2), were extracted from UNICEF databases. Joinpoint regression analysis was employed to identify joinpoints in the time series and to estimate Annual Percent Changes (APCs) and Average Annual Percent Changes (AAPCs) over predefined timeframes. The coverages for DTP1 and MCV1 exhibit a similar trend, overall characterized by four joinpoints, one of which is in 2019. In contrast, the coverage for DTP3 does not show a significant temporal trend and lacks joinpoints, while the vaccination coverage for MCV2 shows a steadily increasing trend, with three identified joinpoints. A comparative analysis with the pre-pandemic period reveals a significant increase in the number of countries characterized by a decreasing trend during the pandemic period for all considered vaccination coverages, as indicated by the negative AAPC values. These results highlight the effect of the pandemic on childhood vaccination coverage. Compared to a mere descriptive analysis, the temporal analysis of trends using joinpoint regression provides significant opportunities to identify variations in vaccination coverages and pinpoint areas for intervention in future vaccination strategies.

Vaccine coverage rate: opportunities and challenges in managing the expanded program on immunization

Background: This study aims to determine the vaccine coverage rate in the expanded immunization program of children born from 2016-2020 through periods with and without the impact of the COVID-19 pandemic. Methods: The retrospective cross-sectional study with data, taken from the National Immunization Information System at two points of time (January 2021 and September 2022), was conducted on all children born from 2016 to 2020 with registered addresses in Ho Chi Minh City. Results: There are 3,1% of the population from other provinces entering Ho Chi Minh City and 1,8% of Ho Chi Minh City's population leaving the city. The overall fully vaccinated rate of children from 2016 to 2020 is 86,9%. The second measles coverage rate and diphtheria pertussis tetanus 4th dose (DPT4) coverage rate for children born in 2016-2020 was 78,1% and 72,4%. The DPT4 missed dose rate increased from 14,2% to 24,6% and the second measles missed shot rate increased from 8,9% to 19,5%. Under the impact of the COVID-19 pandemic, the vaccination coverage rate by age group decreased during the COVID-19 epidemic stages. After the epidemic, it recovered but the rate was not high. Conclude: There was a fluctuation in HCM population when retrospectively examining data at 2 points of time. The rate of vaccination coverage of children under and over 1 year old does not meet the target. The missed dose percentage of vaccines for children under 1 year old is low (diphtheria pertussis tetanus 1st dose (DPT1)-measles 1 or DPT1-3), while the proportion of missed is high in DPT3-DPT4 and Measles 1-Measles 2. The retrospective cross-sectional study only used retrospective data up to September 2022, so it is hard to illustrate a clear recovery after the COVID-19 pandemic. More time is needed for the observation.

Re-evaluating the impact and cost-effectiveness of pneumococcal conjugate vaccine introduction in 112 low-income and middle-income countries in children younger than 5 years: a modelling study

Streptococcus pneumoniae has been estimated to cause 9·18 million cases of pneumococcal pneumonia, meningitis, and invasive non-pneumonia non-meningitis disease and 318 000 deaths among children younger than 5 years in 2015. We estimated the potential impact and cost-effectiveness of pneumococcal conjugate vaccine (PCV) introduction. We updated our existing pseudodynamic model to estimate the impact of 13-valent PCV (PCV13) in 112 low-income and middle-income countries by adapting our previously published pseudodynamic model with new country-specific evidence on vaccine coverage, burden, and post-introduction vaccine impact from WHO-UNICEF estimates of national immunisation coverage and a global burden study. Deaths, disability-adjusted life-years (DALYs), and cases averted were estimated for children younger than 5 years born between 2000 and 2030. We used specific PCV coverage in each country and a hypothetical scenario in which coverage increased to diphtheria-tetanus-pertussis (DTP) levels. We conducted probabilistic uncertainty analyses. Using specific vaccine coverage in countries, we estimated that PCV13 could prevent 697 000 (95% credibility interval 359 000-1 040 000) deaths, 46·0 (24·0-68·9) million DALYs, and 131 (89·0-172) million cases in 112 countries between 2000 and 2030. PCV was estimated to prevent 5·3% of pneumococcal deaths in children younger than 5 years during 2000-30. The incremental cost of vaccination would be I$851 (510-1530) per DALY averted. If PCV coverage were increased to DTP coverage in 2020, PCV13 could prevent an additional 146 000 (75 500-219 000) deaths. The inclusion of real-world evidence from lower-income settings revealed that delays in PCV roll-out globally and low PCV coverage have cost many lives. Countries with delays in vaccine introduction or low vaccine coverage have experienced many PCV-preventable deaths. These findings underscore the importance of rapidly scaling up PCV to achieve high coverage and maximise vaccine impact. Bill & Melinda Gates Foundation and Gavi, the Vaccine Alliance.

The recombinant shingles vaccine is associated with lower risk of dementia

There is emerging evidence that the live herpes zoster (shingles) vaccine might protect against dementia. However, the existing data are limited and refer only to the live vaccine, which is now discontinued in the United States and many other countries in favor of a recombinant vaccine. Whether the recombinant shingles vaccine protects against dementia remains unknown. Here we used a natural experiment opportunity created by the rapid transition from the use of live to the use of recombinant vaccines to compare the risk of dementia between vaccine types. We show that the recombinant vaccine is associated with a significantly lower risk of dementia in the 6 years post-vaccination. Specifically, receiving the recombinant vaccine is associated with a 17% increase in diagnosis-free time, translating into 164 additional days lived without a diagnosis of dementia in those subsequently affected. The recombinant shingles vaccine was also associated with lower risks of dementia than were two other vaccines commonly used in older people: influenza and tetanus–diphtheria–pertussis vaccines. The effect was robust across multiple secondary analyses, and was present in both men and women but was greater in women. These findings should stimulate studies investigating the mechanisms underpinning the protection and could facilitate the design of a large-scale randomized control trial to confirm the possible additional benefit of the recombinant shingles vaccine.

Child COVID-19 vaccine uptake among participants of the 2015 Pelotas (Brazil) Birth Cohort Study

ObjectiveTo analyze COVID-19 vaccine uptake in children and to investigate factors associated with two outcomes variables: (a) not even beginning; (b) not completing the COVID-19 vaccine series. MethodsWe used data of children aged 6–7 years from the 2015 Pelotas c Birth Cohort Study. COVID-19 vaccination status was collected from immunization cards and National Immunization Program Information System. Adjusted analyses were performed using a hierarchical model to identify factors associated with the two study outcomes. ResultsAmong 3867 children, 20.7 % (95 % CI, 19.5 %–22.0 %) did not even begin the 2-dose primary COVID-19 vaccine series, and 28.2 % (95 % CI, 26.6 %–29.8 %) did not complete the series with the second dose. Children not even beginning the COVID-19 vaccine series were more likely to have a White mother, not to have obesity, to have a history of COVID-19 infection, to have received non-recommended drugs for COVID-19, to be afraid of needles, and to have an incomplete diphtheria-tetanus-pertussis (DTP) and poliovirus immunization schedule. Not completing the 2-dose series was associated with lower maternal age and education, mother’s self-identification as White or Brown, lower household income, lack of access to health services, not having completed the DTP and poliovirus immunization schedule and living with a person with a history of infection with COVID-19. ConclusionThe results highlight a vaccine-hesitant parents’ group who chose not beginning the COVID-19 vaccine series of their children and, another group of parents who failure to complete the child’s series due to difficulty accessing health services.

Association of COVID-19 Vaccination With Changes in Smell and Taste.

Since the introduction of vaccines for severe acute respiratory syndrome coronavirus 2in the United States, there has been significant vaccine hesitancy, in part due to fear of adverse effects. We sought to investigate the rates of smell and taste changes after COVID-19 vaccination compared to other common vaccines. Our study cohort included individuals identified by Current Procedural Terminology code in the TriNetX database receiving the COVID-19 first series, COVID-19 booster, influenza, tetanus, diphtheria, pertussis (TDAP), or pneumococcal vaccines between December 15, 2020, and August 15, 2023. After 1:1 propensity score matching, postvaccination incidence of disturbance of smell and taste was significantly less likely after COVID-19 first series vaccine compared to influenza (odds ratios, OR: 0.27 [95% confidence interval, CI: 0.20-0.36]), TDAP (OR: 0.35 [95% CI: 0.26-0.47]), and pneumococcal vaccines (OR: 0.17 [95% CI: 0.09-0.32]). Similarly, incidence of disturbance of smell and taste was significantly less likely after COVID-19 booster vaccine compared to the influenza (OR: 0.60 [95% CI: 0.48-0.76]), TDAP (OR: 0.63 [95% CI: 0.47-0.85]), and pneumococcal vaccines (OR: 0.44 [95% CI: 0.28-0.68]). This study builds upon the literature demonstrating the safety of COVID-19 vaccination.

Childhood vaccination trends during 2019 to 2022 in Tanzania and the impact of the COVID-19 pandemic

ABSTRACT The COVID-19 pandemic has significantly disrupted healthcare systems at all levels globally, notably affecting routine healthcare services, such as childhood vaccination. This study examined the impact of these disruptions on routine childhood vaccination programmes in Tanzania. We conducted a longitudinal study over four years in five Tanzanian regions: Mwanza, Dar es Salaam, Mtwara, Arusha, and Dodoma. This study analyzed the trends in the use of six essential vaccines: Bacille Calmette-Guérin (BCG), bivalent Oral Polio Vaccine (bOPV), Diphtheria Tetanus Pertussis, Hepatitis-B and Hib (DTP-HepB-Hib), measles-rubella (MR), Pneumococcal Conjugate Vaccine (PCV), and Rota vaccines. We evaluated annual and monthly vaccination trends using time-series and regression analyses. Predictive modeling was performed using an autoregressive integrated moving average (ARIMA) model. A total of 32,602,734 vaccination events were recorded across the regions from 2019 to 2022. Despite declining vaccination rates in 2020, there was a notable rebound in 2021, indicating the resilience of Tanzania’s immunization program. The analysis also highlighted regional differences in vaccination rates when standardized per 1000 people. Seasonal fluctuations were observed in monthly vaccination rates, with BCG showing the most stable trend. Predictive modeling of BCG indicated stable and increasing vaccination coverage by 2023. These findings underscore the robustness of Tanzania’s childhood immunization infrastructure in overcoming the challenges posed by the COVID-19 pandemic, as indicated by the strong recovery of vaccination rates post-2020. We provide valuable insights into the dynamics of vaccination during a global health crisis and highlight the importance of sustained immunization efforts to maintain public health.

Exploring the “Urban Advantage” in Access to Immunization Services: A Comparison of Zero-Dose Prevalence Between Rural, and Poor and Non-poor Urban Households Across 97 Low- and Middle-Income Countries

Urban children are more likely to be vaccinated than rural children, but that advantage is not evenly distributed. Children living in poor urban areas face unique challenges, living far from health facilities and with lower-quality health services, which can impact their access to life-saving vaccines. Our goal was to compare the prevalence of zero-dose children in poor and non-poor urban and rural areas of low- and middle-income countries (LMICs). Zero-dose children were those who failed to receive any dose of a diphtheria-pertussis-tetanus (DPT) containing vaccine. We used data from nationally representative household surveys of 97 LMICs to investigate 201,283 children aged 12–23 months. The pooled prevalence of zero-dose children was 6.5% among the urban non-poor, 12.6% for the urban poor, and 14.7% for the rural areas. There were significant differences between these areas in 43 countries. In most of these countries, the non-poor urban children were at an advantage compared to the urban poor, who were still better off or similar to rural children. Our results emphasize the inequalities between urban and rural areas, but also within urban areas, highlighting the challenges faced by poor urban and rural children. Outreach programs and community interventions that can reach poor urban and rural communities—along with strengthening of current vaccination programs and services—are important steps to reduce inequalities and ensure that no child is left unvaccinated.

Persistence and heterogeneity of the effects of educating mothers to improve child immunisation uptake: Experimental evidence from Uttar Pradesh in India

Childhood vaccinations are among the most cost-effective health interventions. Yet, in India, where immunisation services are widely available free of charge, a substantial proportion of children remain unvaccinated. We revisit households 30 months after a randomised experiment of a health information intervention designed to educate mothers on the benefits of child vaccination in Uttar Pradesh, India. We find that the large short-term effects on the uptake of diphtheria–pertussis–tetanus and measles vaccination were sustained at 30 months, suggesting the intervention did not simply bring forward vaccinations. We apply causal forests and find that the intervention increased vaccination uptake, but that there was substantial variation in the magnitude of the estimated effects. We conclude that characterising those who benefited most and conversely those who benefited least provides policy-makers with insights on how the intervention worked, and how the targeting of households could be improved.

Non-specific protection against severe COVID-19 associated to typhoid fever and DTP vaccination

Trained immunity (TRAIM) or the enhanced non-specific immune response after primary stimulation by infection or vaccination is a recent but well-recognized concept. To verify its predictions, our objective was to determine the effects of two bacterial vaccines, typhoid fever (TFV) and diphtheria-tetanus-pertussis (DTP) on the infection, hospitalization and death frequencies associated to COVID-19 in a retrospective study on subjects vaccinated or not with TFV and DTP in the 4 years prior to the start of COVID-19 pandemia in the Basque Country (Spain). The studied outcome records were split into two periods according to COVID-19 vaccination, the pre-vaccination (ACV) from March to December 2020 and the post-vaccination (PCV) from September 2021 to June 2022). In total, 13,673 subjects were vaccinated against TFV and 42,997 against DTP.A total of 2,005,084 individual records were studied in the ACV period and 1,436,693 in the PCV period. The proportion of infection, hospitalization and death associated to COVID-19 among controls in ACV was 4.97 %, 7.14 % and 3.54 %, respectively vs. 7.20 %, 2.24 % and 0.10 % among TFV subjects. Regarding DTP, the proportions were 4.97 %, 7.12 % and 3.58 % for controls and 5.79 %, 5.79 % and 0.80 % for vaccinees. In the PCV period, the proportion of infection, hospitalization and death among controls was 21.89 %, 2.62 % and 0.92 %, respectively vs. 31.19 %, 0.76 %, 0.00 % among TFV. For DTP, infection, hospitalization and death proportions were 21.89 %, 2.62 % and 0.92 %, respectively, among controls vs. 32.03 %, 1.85 % and 0.24 % among vaccinated subjects. The corresponding combined ACV and PCV odds ratios (OR) for SARS-CoV2 infection were 1.505 (95%CI 1.455–1.558; p < 0.0001; reduction −41.85 %) and 1.633 (95%CI 1.603–1.662; p < 0.0001; reduction −51.74 %), for TFV and DTP, respectively. Regarding COVID-19 associated hospitalization, the OR were 0.295 (95%CI 0.220–0.396; p = 0.0001; reduction 69.74 %) and 0.667 (95%CI 0.601–0.741; p = 0.0001; reduction 32.44 %), for TFV and DTP, respectively). COVID-19 associated death OR were 0.016 (95%CI 0.002–0.113, p < 0.0001; reduction 98.38 %) and 0.212 (95%CI 0.161–0.280; p = 0.0001; reduction 78.52 %), for TFV and DTP, respectively. We conclude that TRAIM effects by TFV and DTP vaccination in the four years prior to the pandemic SARS-CoV2 were supported by slightly increased infection rates, but strongly reduced COVID-19 associated hospitalization and death rates.

Factors Influencing DPT Immunization Completion among Children: Insights from Nakawa Division, Kampala, Uganda

This study investigates the factors influencing DPT (Diphtheria, Pertussis, Tetanus) immunization completion among children aged 4–23 months in Nakawa Division, Kampala, Uganda. Utilizing a descriptive cross-sectional design with both qualitative and quantitative methodologies, data were collected from 271 participants using researcher-guided questionnaires. The analysis revealed a high DPT immunization completion rate of 94%, meeting WHO targets. Significant factors associated with completion included caretaker age, religion, and attitude toward vaccine safety and acceptability, as well as health service factors like distance to the facility, ANC attendance, convenience of immunization days, and vaccine availability. However, child-related factors such as age, gender, and birth order showed no significant association. These findings underscore the importance of targeted interventions to address caregiver perceptions and improve health service delivery for sustained immunization coverage. Keywords: Diphtheria; Pertussis-Tetanus (Pertussis is commonly known as whooping cough); DPT Immunization; Completion Status; Nakawa Division, Kampala-Uganda.

Global vaccine coverage and childhood survival estimates: 1990-2019.

To quantify the association between reduction in child mortality and routine immunization across 204 countries and territories from 1990 to 2019. We used child mortality and vaccine coverage data from the Global Burden of Disease Study. We used a modified child survival framework and applied a mixed-effects regression model to estimate the reduction in deaths in children younger than 5years associated with eight vaccines. Between 1990 and 2019, the diphtheria-tetanus-pertussis (DTP), measles, rotavirus and Haemophilus influenzae type b vaccines were significantly associated with an estimated 86.9 (95% confidence interval, CI: 57.2 to 132.4) million fewer deaths in children younger than 5years worldwide. This decrease represented a 24.2% (95% CI: 19.8 to 28.9) reduction in deaths relative to a scenario without vaccines. The DTP and measles vaccines averted 46.7 (95% CI: 30.0 to 72.7) million and 37.9 (95% CI: 25.4 to 56.8) million deaths, respectively. Of the total reduction in child mortality associated with vaccines, 84.2% (95% CI: 83.0 to 85.1) occurred in 73 countries supported by Gavi, the Vaccine Alliance, with an estimated 45.4 (95% CI: 29.8 to 69.2) million fewer deaths from 2000 to 2019. The largest reductions in deaths associated with these four vaccines were in India, China, Ethiopia, Pakistan and Bangladesh (in order of the size of reduction). Vaccines continue to reduce childhood mortality significantly, especially in Gavi-supported countries, emphasizing the need for increased investment in routine immunization programmes.

Генотипическая характеристика штаммов Bordetella pertussis — кандидатов для получения коклюшного компонента вакцинных препаратов (сообщение I)

Vaccination is an effective means of preventing pertussis infection. The purpose of this work was to improve vaccines available in the Russian Federation in general and actualize vaccine strains used for the production thereof in particular. We studied B. pertussis strains isolated in Moscow, Voronezh, Novosibirsk, Ulyanovsk and Chelyabinsk regions, and eight production strains part of the adsorbed diphtheria-pertussis-tetanus (DPT) vaccine. Multilocus antigenic sequence typing (MAST) and whole genome multilocus sequence typing (wgMLST) were used for genotyping. We studied cultural morphological, enzymatic, serological, and genotypic properties of the candidate B. pertussis strains, and compared their genotypic properties to those of B. pertussis vaccine strains from the current composition of the DPT vaccine. Candidate strains belong to four genotypes: ptxА1/ptxВ2/ptxС2/ptxР3/fim2-2/fim3-2/prn2, ptxА1/ptxВ2/ptxС2/ptxР3/fim2-2/fim3-2/prn9, ptxА1/ptxВ2/ptxС2/ptxР3/fim2-1/fim3-1/prn1 and ptxА1/ptxВ2/ptxС2/ptxР3/fim2-2/fim3-1/prn2. Current vaccine strains were from other six genotypes: ptxА2/ptxВ1/ptxС1/ptxР1/fim2-1/fim3-1/prn1, ptxА2/ptxВ2/ptxС1/ptxР2/fim2-1/fim3-1/prn1, ptxА4/ptxВ1/ptxС1/ptxР2/fim2-1/fim3-1/prn1, ptxА2/ptxВ2/ptxС1/ptxР1/fim2-1/fim3-1/prn1, ptxА4/ptxВ2/ptxС1/ptxР2/fim2-1/fim3-1/prn1 and ptxА1/ptxВ2/ptxС1/ptxР1/fim2-1/fim3-1/prn1. With the help of wgMLST, we established affiliation of all candidate strains of B. pertussis to ST2.

Exploring trends and determinants of basic childhood vaccination coverage: Empirical evidence over 41 years.

Vaccination is widely considered to be one of the most important prevention measures as a health strategy. This paper examines trends in basic childhood vaccination coverage and which country and time-dependent determinants may have influenced childhood immunization rates (1-dose BCG, 1- and 3-dose DTP (diphtheria, tetanus, pertussis), 1-dose measles, and 3-dose polio) between 1980 and 2020 across 94 countries. We identify economic, inequality, demographic, health, education, labor market, environmental, and political stability factors of immunization. To do this, we use data from the annual WHO and United Nations International Children's Emergency Fund (UNICEF) coverage estimates. The empirical analysis consists of generalized estimating equation models to assess relationships between immunization rates and socioeconomic factors. Additionally, we follow the Barro and Sala-i-Martín approach to identify conditional convergence. Our findings show the strongest positive statistically significant association between immunization rates and GDP per capita, as well as births attended by skilled health staff. Moreover, our research demonstrates conditional convergence, indicating that countries converge towards different steady states. The present study brings new insights to investigating the determinants of childhood vaccination coverage and provides significant implications for health policies.

Child immunization status according to number of siblings and birth order in 85 low- and middle-income countries: a cross-sectional study

Identification of unvaccinated children is important for preventing deaths due to infections. Number of siblings and birth order have been postulated as risk factors for zero-dose prevalence. We analysed nationally representative cross-sectional surveys from 85 low and middle-income countries (2010-2020) with information on immunisation status of children aged 12-35 months. Zero-dose prevalence was defined as the failure to receive any doses of DPT (diphtheria-pertussis-tetanus) vaccine. We examined associations with birth order and the number of siblings, adjusting for child's sex, maternal age and education, household wealth quintiles and place of residence. Poisson regression was used to calculate zero-dose prevalence ratios. We studied 375,548 children, of whom 13.7% (n=51,450) were classified as zero-dose. Prevalence increased monotonically with birth order and with the number of siblings, with prevalence increasing from 11.0% for firstborn children to 17.1% for birth order 5 or higher, and from 10.5% for children with no siblings to 17.2% for those with four or more siblings. Adjustment for confounders attenuated but did not eliminate these associations. The number of siblings remained as a strong risk factor when adjusted for confounders and birth order, but the reverse was not observed. Among children with the same number of siblings, there was no clear pattern in zero-dose prevalence by birth order; for instance, among children with two siblings, the prevalence was 13.0%, 14.7%, and 13.3% for firstborn, second, and third-born, respectively. Similar results were observed for girls and boys. 9513 families had two children aged 12-35 months. When the younger sibling was unvaccinated, 61.9% of the older siblings were also unvaccinated. On the other hand, when the younger sibling was vaccinated, only 5.9% of the older siblings were unvaccinated. The number of siblings is a better predictor than birth order in identifying children to be targeted by immunization campaigns. Zero-dose children tend to be clustered within families. Gavi, the Vaccine Alliance.

The 2020 immunization programme landscape: Piloting an assessment metric to evaluate the maturity of national immunization programmes across the life course

BackgroundThe World Health Organization (WHO) encourages countries to provide appropriate vaccinations for children, adolescents, and relevant adult populations. Childhood programme have been the focus of global investments, but recent pandemics have increasingly demonstrated the value of life course vaccination. Our objective is to compare national life course immunization programmatic maturity prior to mass COVID-19 vaccine introduction, the largest adult vaccination programme, globally. As coverage estimates (typically used to assess childhood programmes) are not available for adult vaccinations, this analysis pilots a standardized quantitative metric of programmatic maturity. MethodsThrough consultation with vaccination experts, we developed a standardized approach to assess national immunization programme maturity across the life course. In accordance with expert input, five vaccines were selected to represent delivery across the life course: diphtheria tetanus toxoid and pertussis (DTP); measles (MCV) second dose; human papillomavirus (HPV) final dose; pneumococcal conjugate (PCV) final dose; and seasonal influenza annual dose. Experts recommended inclusion of the following indicators for each vaccine: a legal mandate (national policy), experience delivering the vaccine (programme duration), and vaccine use (uptake for relevant populations). We developed a metric accordingly that provides up to 5 points per vaccine (“vaccine specific maturity score”) which when summed forms the “life course maturity score”, with a maximum score of 25. We analysed the prevalence of national policies, experience, and use by region and World Bank income group. ResultsMore than 55% of the 194 WHO Member States had childhood vaccine policies for all three of the vaccines considered (DTP, MCV, and PCV) compared to 60% for HPV (proxy for adolescent vaccination programme) and 52% for seasonal influenza (proxy for adult vaccination programme). Childhood vaccination programmes (e.g., MCV and DTP) had the highest vaccine specific maturity scores, while seasonal influenza and HPV vaccination programmes had much lower scores. The national life course maturity scores ranged from 1 to 23, with a global median of 12 (IQR: 8; 16). DiscussionThe piloted metric provides an overview of the maturity of life course immunization programmes. The metric is structured to be a flexible, rapid resource that can be used to assess other combinations of vaccines across the life course. The findings from this paper provide a baseline of immunization programme maturity for childhood, adolescent, and adult vaccination programmes immediately prior to the COVID-19 vaccine introduction. This maturity score, or adaptations of this approach, could be used to monitor the trajectory of national immunization programme maturity across the life course in the years ahead.

Evolution in key indicators of maternal and child health across the wealth gradient in 41 sub-Saharan African countries, 1986–2019

BackgroundAggregate trends can be useful for summarizing large amounts of information, but this can obscure important distributional aspects. Some population subgroups can be worse off even as averages climb, for example. Distributional information can identify health inequalities, which is essential to understanding their drivers and possible remedies.MethodsUsing publicly available Demographic and Health Survey (DHS) data from 41 sub-Saharan African countries from 1986 to 2019, we analyzed changes in coverage for eight key maternal and child health indicators: first dose of measles vaccine (MCV1); Diphtheria-Pertussis-Tetanus (DPT) first dose (DPT1); DPT third dose (DPT3); care-seeking for diarrhea, acute respiratory infections (ARI), or fever; skilled birth attendance (SBA); and having four antenatal care (ANC) visits. To evaluate whether coverage diverged or converged over time across the wealth gradient, we computed several dispersion metrics including the coefficient of variation across wealth quintiles. Slopes and 5-year moving averages were computed to identify overall long-term trends.ResultsAverage coverage increased for all quintiles and indicators, although the range and the speed at which they increased varied widely. There were small changes in the wealth-related gap for SBA, ANC, and fever. The wealth-related gap of vaccination-related indicators (DPT1, DPT3, MCV1) decreased over time. Compared to 2017, the wealth-gap between richest and poorest quintiles in 1995 was 7 percentage points larger for ANC and 17 percentage points larger for measles vaccination.ConclusionsMaternal and child health indicators show progress, but the distributional effects show differential evolutions in inequalities. Several reasons may explain why countries had smaller wealth-related gap trends in vaccination-related indicators compared to others. In addition to service delivery differences, we hypothesize that the allocation of development assistance for health, the prioritization of vaccine-preventable diseases on the global agenda, and indirect effects of structural adjustment programs on health system-related indicators might have played a role.

Missed opportunities: Reducing zero dose children among the urban poor after COVID, Mumbai India, 2022

Reaching urban poor populations poses challenges for equitable immunization coverage. Furthermore, COVID disrupted routine immunization services. In Mumbai, India, first dose diphtheria tetanus pertussis containing vaccine (DTPCV1)coverage dropped from 88% (2019) to 76% (2021).We identified and characterized 125 zero-dose (those withoutDTPCV1)migrant children in urban Mumbai in October 2022.Almost half were born elsewhere than Mumbai; 53% resided at their present location for less than a year. More than half were 12–59 months of age, well-beyond the age for first routine childhood immunizations.Three of four zero dose children had received birth dose vaccination in the hospital; but failed to receive DTPCV1. Vaccine hesitancy, awareness gaps and operational issues were common reasons for non-vaccination. Despite frequent visits to health facilities for illness,only a third of facility staff asked or advised parents about vaccination.Missed opportunities were much more common in private than government facilities.For the vast majority (88%), residential sites were included in local routine immunization micro-plans and distances to immunization sites were short (less than 1 km for 94 % of families).However, planned session frequency was inadequate half of the time.Expanded efforts to reach migrant urban poor children are needed to ensure vaccine equity.