Time Of Vaccination Research Articles

Childhood vaccination timeliness following maternal migration to an informal urban settlement in Kenya

IntroductionTimely receipt of recommended vaccines is a proven strategy to reduce preventable under-five deaths. Kenya has experienced impressive declines in child mortality from 111 to 43 deaths per 1000 live births between 1980 and 2019. However, considerable inequities in timely vaccination remain, which unnecessarily increases risk for serious illness and death. Maternal migration is a potentially important driver of timeliness inequities, as the social and financial stressors of moving to a new community may require a woman to delay her child’s immunizations. This analysis examined how maternal migration to informal urban settlements in Nairobi, Kenya influenced childhood vaccination timeliness. MethodsData came from the Nairobi Urban Health and Demographic Surveillance System, 2002–2018. Migration exposures were migrant status (migrant, non-migrant), migrant origin (rural, urban), and migrant type (first-time, circular [previously resided in settlement]). Age at vaccine receipt (vaccination timeliness) was calculated for all basic vaccinations. Accelerated failure time models were used to investigate relationships between migration exposures and vaccination timeliness. Confounding was addressed using propensity score weighting. ResultsOver one-third of the children of both migrants and non-migrants received at least one dose late or not at all. Unweighted models showed the children of migrants had shorter time to OPV1 and DPT1 vaccine receipt compared to the children of non-migrants. After accounting for confounding only differences in timeliness for DPT1 remained, with the children of migrants receiving DPT1 significantly earlier than the children of non-migrants. Timeliness was comparable among migrants with rural and urban origins and among first-time and circular migrants. ConclusionAlthough a substantial proportion of children in Nairobi’s informal urban settlements do not receive timely vaccination, this analysis found limited evidence that maternal migration and migration characteristics were associated with delays for most doses. Future research should seek to elucidate potential drivers of low vaccination timeliness in Kenya.

Vaccination rates and adherence in premature infants before and after pneumococcal conjugate vaccine schedule change for term infants – A claims database analysis in Germany

BackgroundIn 2015, the German Standing Committee on Vaccination (STIKO) changed the pneumococcal conjugate vaccination (PCV) schedule for mature infants from a 3+1scheme (2, 3, 4, and 11–14 months of age) to a 2+1scheme (2, 4, and 11–14 months of age). For premature infants, the 3+1scheme remained. The aim of this study was to assess vaccination rates, completeness, and timeliness for PCV in premature infants before and after the modified recommendation. MethodsA retrospective claims data analysis using the “Institut für angewandte Gesundheitsforschung Berlin” Research Database was conducted. Premature infants born in 2013 and 2016 with an individual follow-up of 24 months were included. Hexavalent combination (HEXA) vaccination with a consistent 3+1recommendation for mature and premature infants was analyzed as reference vaccination. ResultsAfter 24 months, the PCV rate for at least one dose remained stable in premature newborns of 2016 compared to 2013, while the HEXA vaccination rate increased slightly. However, a significant decrease of a completed PCV schedule (4 doses) in premature infants was noted, whereas the completeness of HEXA vaccination did not change. The timeliness of PCV in premature newborns increased for the first and the booster PCV, while the timeliness of HEXA immunization did not change from 2013 to 2016. ConclusionAlthough STIKO still recommends a 3+1PCV schedule for premature infants in Germany, premature infants were vaccinated according to the changed recommendations for mature born infants. A substantial share of premature infants remained unvaccinated, and their vaccinations were often delayed.

Acceptability of mobile-phone reminders for routine childhood vaccination appointments in Nigeria \u2013 a systematic review and meta-analysis

BackgroundMobile-phone reminders have gained traction among policymakers as a way to improve childhood vaccination coverage and timeliness. However, there is limited evidence on the acceptability of mobile-phone reminders among patients and caregivers. This systematic review and meta-analysis aimed to evaluate the ownership of mobile-phone device and the willingness to receive mobile-phone reminders among mothers/caregivers utilizing routine childhood immunization services in Nigeria.MethodMEDLINE, Scopus, CINAHL, CNKI, AJOL (African Journal Online), and Web of Science were systematically searched for studies on the acceptability of mobile-phone reminders for routine immunization appointments among mothers/caregivers in Nigeria. Studies were assessed for methodological quality using the Newcastle Ottawa Scale and JBI critical appraisal checklists. Meta-analysis was conducted using random-effects model to generate pooled estimates (proportion) of mothers who owned at least one mobile phone and proportion of mothers willing to receive mobile-phone reminders.ResultsSixteen studies (13 cross-sectional and three interventional) involving a total of 9923 mothers across 15 states and the Federal Capital Territory Abuja met inclusion criteria. Pooled estimates showed that the proportion of mothers who owned at least one mobile phone was 96.4% (95% CI = 94.1–98.2%; I2 = 96.3%) while the proportion of mothers willing to receive mobile-phone reminders was 86.0% (95% CI = 79.8–91.3%, I2 = 98.4%). Most mothers preferred to receive text message reminders at least 24 h before the routine immunization appointment day, and in the morning hours. Approximately 52.8% of the mothers preferred to receive reminders in English, the country’s official language.ConclusionCurrent evidence suggests a high acceptability for mobile-phone reminder interventions to improve routine childhood immunization coverage and timeliness. Further studies, however, are needed to better understand unique regional preferences and assess the operational costs, long-term effects, and risks of this intervention.Systematic review protocol registrationPROSPERO CRD42021234183.

Determinants of factors affecting vaccination status of under-five children attending immunoprophylaxis clinic in a tertiary care hospital in central India

Background: Immunization is a key to child survival. Immunization is one of the foremost effective and cost-effective ways to protect children’s lives and futures. Despite clear evidence that vaccines save lives and control disease, millions of young children around the world are missing out, putting them and their communities at risk of disease and deadly outbreaks. This is unacceptable in the present era, where affordable, lifesaving vaccines exist. This study aims to study factors influencing timeliness of vaccination and to assess reasons for delay in immunization.Methods: A Cross-sectional study was conducted among mother/caretaker and children (under five years age) attending immunoprophylaxis clinic at a tertiary health care hospital in central India. Total 171 study subjects accompanied by mother/caretaker are included in the study. Analysis was done using SPSS version 20.0. Chi square test and Fischer’s exact test were used to find the association between characteristics of study subjects and obstetric variables with delayed vaccination.Results: Delayed Vaccination is present in 119 (69.6%) of study subjects. Among the reasons for delayed vaccination, majority were parent related reasons which was present among 84 (70.5%) of study subjects. The association of higher birth order with delayed vaccination was found to be statistically significant.Conclusions: The overall delayed vaccination was present in 69.6% of children and high birth order (3 or more) has a significant association with delayed immunization.

Vaccination information fathers receive during pregnancy and determinants of infant vaccination timeliness

ABSTRACT The information fathers receive about infant vaccination may influence their decision to vaccinate. We describe fathers’ sources of vaccination information and paternal determinants of timely infant vaccinations. Participants were from a child cohort study in New Zealand. The child cohort was established by enrolling pregnant women and their partners. During pregnancy, fathers (n = 4017) of the cohort children born 2009–2010 described information sources that encouraged or discouraged infant vaccination. The National Immunization Register provided infant vaccination data. Independent associations of the vaccination information received by fathers with the timeliness of their infant’s vaccination were determined using multivariable logistic regression. Associations were described using adjusted odds ratios and 95% confidence intervals. One-third of fathers (1430/4017 [36%]) recalled receiving vaccination information, 64% of which encouraged vaccination. Most infants (2900/4017 [72%]) received all their vaccinations on time, however only 58% of Māori infants were vaccinated on time. Paternal determinants of vaccination timeliness were the father receiving discouraging or conflicting information about vaccination, father’s ethnicity, father’s vaccination hesitancy, and whether the mother received vaccination information. To improve vaccination uptake and timeliness, a vaccination conversation with mothers, fathers and whānau could be included in routine antenatal care, informing and supporting decision-making, and addressing concerns. Vaccination education should address present and historic distrust of the health system. Framing vaccination within a Māori model of health and including fathers and whānau in decision-making will address vaccination inequities in New Zealand.

Reaching zero-dose children in India: progress and challenges ahead

Reaching zero-dose children in India: progress and challenges ahead

Age-appropriate vaccination coverage and its determinants in children aged 12\u201336\u2009months in Nepal: a national and subnational assessment

BackgroundVaccination is one of the effective ways to develop immunity against potential life-threatening diseases in children in early age. This study is focused on analysing the age-appropriate vaccination coverage at national and subnational levels and identify the factors associated with age-appropriate coverage in Nepal.Methods460 children aged 12–36 months were included in the study. The data was obtained from Nepal Demographic and Health Survey (NDHS) 2016–17. Age-appropriate coverage of Bacillus Calmette-Guerin vaccine (BCG), oral polio vaccine (OPV) doses 1–3, pentavalent vaccine (PE) doses 1–3, and first dose of measles, mumps, and rubella vaccine (MMR) were estimated using Kaplan Meier method. Multilevel logistic regression with random intercept was used to identify the factors associated with age-appropriate vaccination.ResultsThe crude coverage of the vaccines included in the study ranged from 91.5% (95% CI, 88.5–93.7) for PE3 to 97.8% (95.8–98.7) for BCG. Although the crude coverage of all the vaccines was above 90%, the age-appropriate coverage was significantly low, ranging from 41.5% (36.5–46.6) for PE3 to 73.9% (69.2–78.1) for PE1. Furthermore, high disparity in timely vaccination coverage was observed at regional level. Compared to the age-appropriate vaccination coverage in other provinces, Province 2 had the lowest coverage of all, followed by that in Province 6. The timeliness of vaccination was significantly associated with subnational regions i.e., provinces and the season of childbirth.ConclusionAlthough the immunization program in Nepal has achieved the target of 90% crude coverage of all the childhood vaccines, the age-appropriate coverage is significantly low which undermines the effectiveness of the vaccines administered. Thus, along with crude coverage, timeliness of the vaccines administered should be taken into consideration and thoroughly monitored at national and subnational levels. Provincial government should formulate tailored strategies to ensure the timely administration of the childhood vaccines.

Adherence to the paediatric immunisation schedule in England

Both adequate coverage and adherence to paediatric immunisation schedules are required for optimal protection against vaccine preventable diseases. We studied the timeliness of routine paediatric vaccinations according to the NHS’s immunisation schedule and potential factors of schedule adherence. Immunisation data was obtained from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC). We collected vaccine types, doses, and dates for all routine paediatric vaccines between 2008 and 2018: DTaP/IPV/Hib/HepB, DTaP/IPV/Hib, DTaP/IPV, dTaP/IPV, Td/IPV, MMR, PCV, MenB, MenC, MenACWY, Hib/MenC, RV, HPV. Adherence to the immunisation schedule was calculated for each vaccine and dose. Differences in adherence between genders, NHS regions, and IMD quintiles were analysed. Our study included 6′257′828 vaccinations in 1′005′827 children. Seventy-five percent of first doses were administered within one (for vaccines scheduled in the first year of life) or two months (for vaccines scheduled later in life) following the recommended age, 19% too late and 6% too early. About half of the subsequent doses were given timely. The time between first and second doses was too short for 36% of vaccinations while 13% of second doses were administered too long after the first dose. Third doses were administered timely for 45%, too short for 37%, and too long for 18% of vaccinations. Differences in immunisation schedule adherence between girls and boys were negligible, except for HPV, and differences between the four main NHS regions were small. Overall, immunisation schedule adherence improved slightly with decreasing deprivation according to the Index of Multiple Deprivation. Efforts are required to improve the timeliness of paediatric vaccinations and to assure adequate protection against vaccine preventable diseases. We propose developing a compound measure combining coverage and adherence to provide a better indication of the protection against vaccine preventable diseases in a community.

Pertussis Disease and Antenatal Vaccine Effectiveness in Australian Children.

Population-level studies of severe pertussis extending beyond infancy are sparse, and none in the context of antenatal vaccination. We compared hospitalized pertussis cases from birth to 15 years of age before and after introduction of antenatal immunization. Active surveillance of laboratory-confirmed pertussis hospitalizations in a national network of pediatric hospitals in Australia January 2012 to June 2019. Impact of maternal vaccination was assessed by vaccine effectiveness (VE) in cases and test-negative controls with <2 months of age and by before-after comparison of age distribution of cases. Among cases eligible for one or more vaccine doses, we examined proportions age-appropriately immunized and with comorbidities by age group. Among 419 eligible cases, the proportion <2 months of age significantly decreased from 33.1% in 2012 to 2014 compared with 19.6% in 2016 to 2019 when mothers of only 4 of 17 (23.5%) cases <2 months of age had received antenatal vaccination. VE was estimated to be 84.3% (95% CI, 26.1-96.7). Across all years (2012-2019), of 55 cases 4-11 months of age, 21 (38%) had ≥2 vaccine doses, whereas among 155 cases ≥12 months of age, 122 (85.2%) had ≥3 vaccine doses. Prevalence of comorbidities (primarily cardiorespiratory) increased from 5 (2.1%) <6 months of age to 36 (24.2%) ≥12 months of age (P < 0.001), with 6/16 (38%) cases ≥12 months of age who required intensive care having comorbidities. Below the age of 12 months, prevention of severe pertussis will be maximized by high maternal antenatal vaccine uptake and timeliness of infant vaccine doses. Despite full immunization, we found children ≥12 months of age accounted for 27% of hospitalizations <15 years, with 24% having comorbities, suggesting new vaccine strategies, such as additional doses or more immunogenic vaccines, require evaluation.

The Transition to an Entirely Digital Immunization Registry in Ha Noi Province and Son La Province, Vietnam: Readiness Assessment Study.

BackgroundVietnam is one of the first low- to middle-income countries to develop and implement a national-scale electronic immunization registry. This system was finalized into the National Immunization Information System (NIIS) and scaled up to a national-level system in 2017. As a result, immunization coverage and the timeliness of vaccinations have drastically improved. The time spent on planning and reporting vaccinations has drastically reduced; as a result, vaccination planning and reporting has become more accurate and effective. However, to date, end users have been tasked with managing both the NIIS and paper-based systems in parallel until a formal assessment of the readiness to fully transition to the NIIS is conducted.ObjectiveThis study aims to evaluate the readiness to move to an entirely digital NIIS in 2 provinces of Vietnam—Ha Noi and Son La.MethodsAll health facilities were surveyed to assess their infrastructure, capacity, and need for human resources. NIIS end users were observed and interviewed to evaluate their NIIS knowledge and skill sets. Data from immunization cards and facility paper-based logbooks were compared with data from the NIIS, and vaccine stocks at selected facilities were tallied and compared with data from the NIIS.ResultsOf the 990 health facilities evaluated, most used the NIIS to enter and track immunizations (987/990, 99.7%) and vaccine stocks (889/990, 90.8%). Most had stable electricity (971/990, 98.1%), at least 1 computer (986/990, 99.6%), and ≥2 trained NIIS end users (825/990, 83.3%). End users reported that the NIIS supported them in managing and reporting immunization data and saving them time (725/767, 94.5%). Although many end users were able to perform basic skills, almost half struggled with performing more complex tasks. Immunization data were compiled from the NIIS and immunization cards (338/378, 89.4%) and paper-based logbooks (254/269, 94.4%). However, only 54.5% (206/378) of immunization IDs matched, 57% (13/23) of Bacillus Calmette-Guérin vaccination records were accurate, and 70% (21/30) of the facilities had consistent physical vaccine stock balances. The feedback received from NIIS end users suggests that more supportive supervision, frequent refresher training for strengthening their skill sets, and detailed standardized guides for improving data quality are needed.ConclusionsThe readiness to transition to a digital system is promising; however, additional resources are required to address the timeliness, completeness, and accuracy of the data.

Assessing Vaccine Coverage and Timeliness in Bamako, Mali after the Introduction of Rotavirus Vaccine: A Modified Immunization Cluster Survey.

ABSTRACT.Vaccine coverage and timeliness are critical metrics for evaluating the performance of immunization programs. Following the introduction of rotavirus vaccine in Bamako, Mali, we conducted two cluster surveys spaced approximately 1 year apart to evaluate these metrics among children 9 to 20 months of age. Using the child’s immunization card or the medical record at the center of administration, each selected child’s immunization status was determined at 9 and 12 months of age. Deviations from the WHO-recommended immunization schedule were described by the median delay and fraction of children receiving doses outside of recommended age ranges. Overall, 1,002 children were enrolled in the two surveys combined; 80.1% of children born 7 to 12 months after introduction (survey 1) received three doses of pentavalent rotavirus vaccine (ROTA3) by 9 months of age, which increased to 86.1% among children born 17 to 26 months after introduction (survey 2). Concomitantly, coverage with the third dose of diphtheria-pertussis-tetanus-containing vaccine (DPT3) by age 9 months was 86.5% (survey 1) and 88.9% (survey 2); by age 12 months, 61.3% and 72.4% of children, respectively, had received all scheduled immunizations. The median delay in ROTA3 and DPT3 administration were similar at about 3.4 weeks. Within 3 years of introduction, coverage of rotavirus vaccine among Bamako infants achieved coverage similar to DPT3 and is approaching the Global Vaccine Action Plan goal of 90% coverage by 2020. However, timeliness of coverage remains a concern.

A hospital-based cross-sectional study for assessment of immunization status of children in western Maharashtra, India

Background: Immunization against vaccine-preventable diseases is a fundamental right of children and a way to reduce childhood mortality and morbidity; thus, it is a way to improve the health of the community. Delayed vaccination increases the susceptibility of a child to vaccine-preventable diseases and also affects herd immunity. So this study was undertaken to assess the immunization status of children attending a tertiary care hospital that caters to urban as well as rural populations, focusing on the timeliness of vaccination, and to explore the predictors of vaccination delay. Materials and Methods: A cross-sectional study was carried out among 302 immunization attendees of 12–23 months of age in the immunization outpatient department of a tertiary care hospital. Parents were interviewed, and vaccination dates were obtained from vaccination cards and assessed for vaccination delay. Results: From a total of 302 children of age 12 to 23 months who enrolled in the study, 165 (54.64%) children were vaccinated on time and 137 (45.36%) children had vaccination delays. When assessing vaccination delay, 24 (7.95%), 44 (14.57%), and 118 (39.07%) children were found to have vaccination delay for Bacille Calmette-Guerin (BCG), pentavalent vaccine (PENTA1), and magnetic resonance imaging (MR1), respectively. Out of them, 49 (16.22%) children had vaccination delay for more than one vaccine. Age at first pregnancy, place of delivery, gender, birth order, and birth weight of the child were found to be statistically significant for delayed vaccination. Conclusion: Delays in vaccination can be addressed by offering mobile vaccination clinic facilities to migrant people as well as raising community knowledge about the importance of timely child vaccination through the targeted approach: Information, Education, and Communication (IEC) activities.

Childhood immunisation timeliness and vaccine confidence by health information source, maternal, socioeconomic, and geographic characteristics in Albania

BackgroundAlbania is facing decreasing childhood immunisation coverage and delay in timeliness of vaccination despite a growing economy and universal health insurance. Our aim is to estimate childhood immunisation timeliness and vaccine confidence associated with health information source, maternal, socioeconomic, and geographic characteristics in Albania.MethodsWe used the 2017–2018 Albania Demographic and Health Survey to analyse childhood immunisation timeliness and vaccine confidence among 2113 and 1795 mothers of under-5-year-old children respectively using simple and multivariable logistic regression.ResultsAmong mothers of under-5-year-old children in Albania, 78.1% [95% CI: 74.3, 81.5] never postponed or rejected childhood vaccines. Immunisation delay was reported by 21.3% [18.0, 25.1] of mothers, but a majority (67.0%) were caused by the infant’s sickness at the time of vaccination, while a minority (6.1%) due to mothers’ concerns about vaccine safety and side effects. Vaccine confidence was high among the mothers at 92.9% [91.0, 94.4] with similar geographical patterns to immunisation timeliness. Among 1.3% of mothers who ever refused vaccination of their children, the main concerns were about vaccine safety (47.8%) and side effects (23.1%). With respect to childhood immunisation timeliness, after controlling for other background characteristics, mothers whose main health information source was the Internet/social media had 34% (adjusted odds-ratio AOR = 0.66 [0.47, 0.94], p = 0.020) lower odds in comparison to other sources, working mothers had 35% (AOR = 0.65 [0.47, 0.91], p = 0.013) lower odds in comparison to non-working mothers, mothers with no education had 86% (AOR = 0.14 [0.03, 0.67], p = 0.014) lower odds compared to those who completed higher education, and mothers living in AL02-Qender and AL03-Jug regions had 62% (AOR = 0.38 [0.23, 0.63], p < 0.0001) and 64% (AOR = 0.36 [0.24, 0.53], p < 0.0001) lower odds respectively in comparison to those residing in AL01-Veri region (p < 0.0001). With respect to vaccine confidence, mothers whose main health information source was the Internet/social media had 56% (AOR = 0.44 [0.27, 0.73], p = 0.002) lower odds in comparison to other sources, single mothers had 92% (AOR = 0.08 [0.01, 0.65], p = 0.019) lower odds compared to those married/living with a partner, mothers of specific ethnicites (like Roma) had 61% (AOR = 0.39 [0.15, 0.97], p = 0.042) lower odds in comparison to mothers of Albanian ethnicity, and mothers living in AL03-Jug region had 67% (AOR = 0.33 [0.19, 0.59], p ≤ 0.0001) lower odds compared to mothers residing in AL01-Veri region.ConclusionsReinforcement of scientific evidence-based online communication about childhood immunisation in combination with tracking and analysis of vaccine hesitancy sentiment and anti-vaccination movements on the Internet/social media would be beneficial in improving immunisation timeliness and vaccine confidence in Albania. Since parents tend to search online for information that would confirm their original beliefs, traditional ways of promoting vaccination by healthcare professionals who enjoy confidence as trusted sources of health information should be sustained and strengthened to target the inequities in childhood immunisation timelines and vaccine confidence in Albania.

In-hospital and web-based intervention to counteract vaccine hesitancy in very preterm infants\u2019 families: a NICU experience

BackgroundVaccine hesitancy is a global problem, carrying significant health risks for extremely vulnerable population as that of preterm infants. Social media are emerging as significant tools for public health promotion. Our aim was to evaluate both the coverage and the timeliness of routine immunizations in a cohort of preterm infants (< 33 weeks of gestational age) at 24 months of age whose families have been subjected to in-hospital and web-based interventions to counteract vaccine hesitancy.MethodsFor a period of 2 years parents of preterm infants were instructed during their follow up visits by a member of the NICU team to get correct informations about vaccines from a social network page. Vaccination rates of preterm infants were assessed at 24 months of chronological age with an electronic database and compared to both general population and historical cohort.ResultsCoverage and timeliness of vaccinations at 24 months of age of 170 preterm infants were analyzed in December 2019. Gestational age and birth weight median (IQR) were, respectively, 31.0 (5.0) weeks and 1475.0 (843.8) g. Coverage rates were similar to those of the regional population (p > 0.05), while timeliness of administration was significantly delayed compared to the recommended schedule (p < 0.001). Age of administration was not correlated with either body weight and gestational age at birth (Spearman rank, p > 0.05). DTaP-IPV-HBV-Hib 2nd and 3rd doses, MMR and Varicella vaccines coverage data were higher compared to historical cohort (p < 0.05).ConclusionIncreasing vaccine confidence through web-based interventions could have a positive impact on vaccination acceptance of parents of preterm infants, although timeliness results still delayed. There is a strong need to develop different and effective vaccination strategies to protect this very vulnerable population.

Duration of protection against Bordetella pertussis infection elicited by whole-cell and acellular vaccine priming in Polish children and adolescents

BackgroundIn the context of reported resurgence of pertussis in the last decade, researchers hypothesized that acellular (aP) pertussis vaccines elicit a shorter-lived protection compared to whole-cell (wP) pertussis vaccines. However, in the studies seeking to demonstrate this hypothesis, exposure to each vaccine type was not concurrent, and contradictory epidemiologic modeling questioned its validity. The context of pertussis vaccination history in Poland, with both vaccine types used concurrently in comparable proportions, provided an opportunity to investigate this hypothesis. We sought to compare waning of protection by primary series vaccine type by measuring anti-pertussis toxin antibody concentrations as proxy for recent infection. Materials and methodsSerological samples from 2,745 children and adolescents aged ≥5 years and <16 years and with completed 5-dose pertussis vaccination series were tested by ELISA for pertussis toxin (PT) antibodies. Participants were stratified by type of priming vaccine (wP or aP). Vaccination timeliness and priming-specific trends in anti-PT antibody levels by time since last vaccine dose were analyzed. ResultsA total of 1,161 (42.5%) children received wP vaccines, and 1,314 (48.1%) received aP vaccines for their primary series and toddler booster. Overall, 53.57% of the subjects received doses 2–4 in a timely manner, while only 41.52% received all 5 doses at the recommended intervals. Using GMCs or seropositivity measures, both priming groups showed a re-increase in anti-PT antibody levels signing infection in recent years from 8 years after the school-entry booster onward. Comparisons did not show any significant differences between the two groups in the timing or intensity of this re-increase. ConclusionOur results clearly confirm that vaccine-elicited immunity against pertussis wanes among adolescents even after a complete infant, toddler and school-entry vaccination series. The timing and intensity of the waning of protection appear similar with whole-cell as with acellular pertussis vaccines.

473Preventable pertussis burden in Australia within the first year of life by improving vaccination timeliness

Abstract Background Previous Australian studies have shown that on-time Diphtheria-Tetanus-Pertussis (DTP) vaccination coverage is 50-60% in certain subpopulations. We estimated the potentially preventable burden of pertussis if, 1) the full primary course and, 2) each dose was given on-time. Methods Perinatal, immunisation, pertussis notification, and death data were linked for 1,412,984 infants born in two Australian states in 2000-2012. A DTP dose administered &amp;gt;15 days after the recommended age was categorised as delayed. For aim 1, pertussis rates up to 1-year of age were compared in infants with ≥1 dose delayed versus all doses on-time, using Poisson regression methods. For aim 2, the expected number of cases preventable by each dose was calculated as the product of the number of cases observed during the period of delay and (1 – dose-specific vaccine effectiveness). Results 58% of infants had all primary DTP doses on time. We estimated that 85 (95% CI: 61-109) cases per 100,000 infants, aged 39-days to 1-year, could have been prevented if all infants had been vaccinated on time; 77% of these infants had received ≥1 DTP dose within the first year of life. Estimated preventable burden attributable to delayed DTP1 (58/100,000) was higher than for DTP2 (26/100,000) and DTP3 (15/100,000). Conclusions and Key messages Poor vaccine timeliness, especially delayed DTP1, is a key contributor to the residual burden of pertussis. These findings can inform cost-benefit analyses of targeted programs and public health messaging to reduce delays.

1159Inequities in on-time childhood vaccination: Evidence from sub-Saharan Africa

Abstract Introduction Vaccination coverage has improved over the past decade but inequalities persist; the poorest, least educated, and rural communities are left behind. Programming has focused on increasing coverage and reaching the hardest to reach children but vaccination timeliness is equally important as delays leave children vulnerable to infections. This study examines the levels and inequities of on-time vaccination in the sub-Saharan African (SSA) region. Methods: The most recent Demographic and Health Surveys or Multiple Indicator Clusters Surveys since 2000 from SSA were used to assess on-time vaccination and inequalities by household wealth, maternal education, and place of residence. Inequalities were quantified using slope index of inequality and concentration index. Results The analysis included 153,632 children aged 12-36 months from 40 SSA countries. Median on-time vaccination coverage was below 50% in all four sub-regions. Differences in on-time vaccination were observed by place of residence in Southern (20.8 pp, 95%CI (0.8; 40.8)), West (17.5 pp, 95%CI (5.1; 29.9)), and Eastern (20.9 pp, 95%CI (6.5; 35.2)) regions. Wealth-related inequities were observed in Southern (22.6 pp, 95%CI (4.0; 41.2)), West (30.6 pp, 95%CI (19.1; 42.1)), and Eastern (26.1 pp, 95%CI (8.2; 44.0)) regions. Significant education-related differences in on-time vaccination were observed in West (20.7 pp, 95%CI (10.9; 30.5)), and Eastern (21.2 pp, 95%CI (7.0; 35.4)) regions. Conclusions On-time vaccination coverage was low in all sub-regions and nearly all countries. Inequalities in on-time immunization by household wealth, place of residence, and education existed in most countries. Concrete strategies to improve levels of timeliness are needed

Linked vaccination coverage surveys plus serosurveys among Ethiopian toddlers undertaken three years apart to compare coverage and serologic evidence of protection in districts implementing the RED-QI approach

In low and middle-income countries, estimating the proportion of vaccinated toddlers in a population is important for controlling vaccine-preventable diseases by identifying districts where immunization services need strengthening. Estimates measured before and several years after specific interventions can assess program performance. However, employing different methods to derive vaccination coverage estimates often yield differing results. MethodsLinked vaccination coverage surveys and seroprotection surveys performed among ~300 toddlers 12–23 months of age in districts (woredas), one per region, of Ethiopia (total, ~900 toddlers) in 2013 to estimate the proportion vaccinated with tetanus toxoid (a proxy for pentavalent vaccine) and measles vaccine. The surveys were followed by implementation of the Reaching Every District using Quality Improvement (RED-QI) approach to strengthen the immunization system.Linked coverage/serosurveys were repeated in 2016 to assess effects of the interventions on vaccination coverage. Indicators included “documented coverage” (vaccination card and/or health facility register records) and “crude coverage” (documented plus parent/caretaker recall for children without cards). Seroprotection thresholds were IgG-ELISA tetanus antitoxin ≥0.05 IU/ml and plaque reduction neutralization (PRN) measles titers ≥120 mIU/ml. FindingsImproved markers in 2016 over 2013 include coverage of pentavalent vaccination, vaccination timeliness, and fewer missed opportunities to vaccinate. In parallel, tetanus seroprotection increased in the 3 woredas from 59.6% to 79.1%, 72.9% to 83.7%, and 94.3 to 99.3%. In 2015, the Ethiopian government conducted supplemental measles mass vaccination campaigns in several regions including one that involved a project woreda and the campaign overlapped with the RED-QI intervention timeframe; protective measles PRN titers there rose from 31.0% to 50.0%. InterpretationThe prevalence of seroprotective titers of tetanus antitoxin (stimulated by tetanus toxoid components within pentavalent vaccine) provides a reliable biomarker to identify children who received pentavalent vaccine. In the three study woredas, the RED-QI intervention appeared to improve immunization service delivery, as documented by enhanced pentavalent vaccine coverage, vaccination timeliness, and fewer missed vaccination opportunities. A measles mass vaccination campaign was followed by a markedly increased prevalence of measles PRN antibodies. Collectively, these observations suggest that wider implementation of RED-QI can strengthen immunization, and periodic linked vaccination surveys/serosurveys can monitor changes.

Improving vaccination coverage and timeliness through periodic intensification of routine immunization: evidence from Mission Indradhanush.

Only an estimated 62% of Indian children under the age of 2 years are fully immunized. We examined the association between India's Mission Indradhanush (MI)—a periodic intensification of the routine immunization program—which was implemented in phases across districts between March 2015 and July 2017, and routine vaccination coverage and timeliness among children. We used data from a 2015 to 2016 national survey of children (n = 29,532) and employed difference‐in‐difference regressions to examine binary indicators of receipt of 11 vaccines and whether vaccines were received at recommended ages. The full immunization rate was 27% higher among children under 2 years old residing in MI phase 1 and 2 districts (intervention group) as compared with those residing elsewhere (control group). The rate of receiving all vaccines at recommended ages was 8% higher in the intervention group. Receiving doses of oral polio vaccine (OPV) birth dose, OPV dose 1 (OPV1), OPV2, OPV3, bacillus Calmette–Guérin, and hepatitis B birth dose vaccines were 9%, 9%, 11%, 16%, 5%, and 19% higher in the intervention group than the control group, respectively. More research is required on the cost‐effectiveness of investing in MI‐type programs as compared with routine immunization.

Assessment of the timeliness of vaccination against pertussis in children of the first year of life and the reasons for the violation of the vaccination schedule

The maximum incidence of pertussis in young children confirms the importance of their timely immunization.The goal is – to study the timeliness of vaccination against whooping cough, causes of violation of the vaccination schedule in young children, the effect of recombinant interferon-a on the post-vaccination period.Materials and methods: the vaccination history and data on the course of the post-vaccination period after immunization with DPT and DaPT vaccines of 469 children at the age of 3–24 months were studied.Results. The analysis showed that 14,9% of the observed children were not vaccinated against whooping cough in a timely manner. Of these: 34,3% had a written refusal to vaccinate (5.1% of the total number of observed children), in 32,8% of cases, the vaccination schedule was violated due to late arrival of parents, 32,9% of children by the start of immunization had medical challenges, and only half of them had justified contraindications. Non-serious side effects associated with immunization were observed in 11.3% of cases, statistically more often with DTP (22,0%) compared with DaPT (5.,5%). General and local reactions, in general, were recorded on DPT (6,9% and 15,1%, respectively) and less often developed with the use of DaPT (1,0% and 4,5%, respectively). Within 1 month after immunization, 16,2% of the observed children had an acute respiratory viral infection of varying severity. Those who did not receive antiviral therapy more often carried the disease in a moderate and severe form, which in all cases led to the postponement of the administration of the second and third doses of the vaccine.Conclusion. To increase the timeliness of vaccination of children against whooping cough, medical professionals should persistently remind parents about the timing of turnout for the next vaccination, when making medical withdrawals, be guided by modern methodological documents and instructions for vaccines. The use of antiviral and immunomodulatory effects of IFN-alpha drugs allows us to comply with the recommended schedule for vaccination of children with a high risk of SARS in the post-vaccination period.