Time Of Vaccination Research Articles

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.

Early childhood vaccination coverage and timeliness by macro-area of origin in children born to foreign women residing in Italy

ObjectivesCountry of origin might affect vaccine uptake in children born to immigrants. We aimed to evaluate differences in childhood vaccination coverage (VC) and timeliness by macro-area of origin of foreign mothers residing in Italy. Study designMulticentre retrospective birth cohorts. MethodsWe analysed data of 23,287 children born in 2009–2014 to foreign women in the cities of Rome, Turin and Treviso. We retrieved data through record-linkage of the population, vaccination and birth registries. We estimated VCs at different ages for vaccines against tetanus, measles and meningococcal group-C, using the Kaplan–Meier method. Factors associated with vaccine uptake were evaluated using multilevel Poisson models. ResultsEstimates of VC at any age and for all antigens were significantly lower in children born to women from Asia and higher in children born to women from Africa, as compared to other macro-areas. Similar differences by area of origin were observed for timeliness; independently of mother's sociodemographic characteristics and neonatal outcomes, the probability of delay vaccination after 2 years of age for each antigen was highest in children born to women from Asia. The risk of missed vaccination for all antigens was significantly higher in children born to younger and unemployed women. ConclusionsFactors related to area of origin (e.g., cultural habits, language skills) are likely to affect parents’ decision to vaccinate their children. These factors, as well as sociodemographic characteristics, should be adequately investigated and addressed to increase vaccine uptake in foreign children, especially those born to Asian women.

Vaccination coverage estimates and utilization patterns of inactivated enterovirus 71 vaccine post vaccine introduction in Ningbo, China

BackgroundIn China, enterovirus 71 (EV71) is the major etiological agents of hand foot mouth disease that poses severe risks to children’s health. Since 2015, three inactivated EV71 vaccines have been approved for use. Previous studies indicated the high willingness of EV71 vaccination in eastern China. However, few studies have assessed coverage and utilization patterns of EV71 vaccine in China.MethodsChildren born during 2012–2018 were sampled and their records were abstracted from Ningbo childhood immunization information management system. Descriptive statistics characterized the study population and assessed coverage and timeliness for EV71 vaccination. Simultaneous administration patterns as well as type of EV71 vaccine used were also evaluated. Bivariate and multivariable analysis was used to examine the relationship of socio-demographic characteristics with vaccination coverage and timeliness.ResultsOf 716,178 children living in Ningbo. One hundred seventy-two thousand two hundred thirty-six received EV71 vaccine with a coverage rate of 24.05% and only 8.61% received vaccination timely. 21.97% of children received the complete two dose EV71 series but only 6.49% completed timely. Vaccination coverage and timeliness increased significantly from 2012 birth cohort to 2018 birth cohort. Relatively higher coverage and timeliness were observed in resident children, Inner districts, high socioeconomic areas and large-scaled immunization clinics. Of 329,569 doses of EV71 vaccine, only 5853(1.78%) doses were administered at the same day as other vaccines.ConclusionsThere is a need for increasing EV71 vaccination coverage and timeliness as well as eliminating disparities among different populations. Our study highlights the importance of simultaneous administration to increasing coverage and timeliness of EV71 vaccination.

Mobile nudges and financial incentives to improve coverage of timely neonatal vaccination in rural areas (GEVaP trial): A 3-armed cluster randomized controlled trial in Northern Ghana.

BackgroundDespite progress in vaccination coverage, timeliness of childhood vaccination remains a challenge in many settings. We aimed to assess if mobile phone-based reminders and incentives to health workers and caregivers could increase timely neonatal vaccination in a rural, low-resource setting.MethodsWe conducted an open-label cluster randomized controlled 1:1:1 trial with three arms in 15 communities in Northern Ghana. Communities were randomized to 1) a voice call reminder intervention; 2) a community health volunteer (CHV) intervention with incentivized rewards; 3) control. In the voice call reminder arm, a study staff member made voice calls to mothers shortly after birth to encourage vaccination and provide personalized information about available vaccination services. In the incentive arm, CHVs promoted infant vaccination and informed women with recent births about available vaccination opportunities. Both CHVs and women were provided small monetary incentives for on-time early infant vaccination in this arm, delivered using mobile phone-based banking applications. No study activities were conducted in control communities. A population-based survey compared vaccination coverage across arms in the pre-intervention and intervention periods. The primary endpoint was completion of at least one dose of Polio vaccine within 14 days of life and BCG vaccination within 28 days of life.ResultsSix-hundred ninety births were identified; 106, 88, and 88 from pre-intervention and 150, 135, and 123 in the intervention period, in the control, voice call reminder and CHV incentive arms, respectively. In adjusted intent-to-treat analysis, voice call reminders were associated with 10.5 percentage point (95% CI: 4.0, 17.1) higher coverage of on-time vaccination, while mobile phone-based incentives were associated with 49.5 percentage point (95% CI: 26.4, 72.5) higher coverage.ConclusionCommunity-based interventions using mobile phone technologies can improve timely early vaccination coverage. A CHV approach with incentives to community workers and caregivers was a more effective strategy than voice call reminders. The impact of vaccination “nudges” via voice calls may be constrained in settings where network coverage and phone ownership are limited.Trial registrationThis trial was registered at ClinicalTrials.gov; NCT03797950.

New Vaccine Introduction and Childhood Vaccination Timeliness in Two Urban, Informal Settlements in Nairobi, Kenya.

New vaccine introduction accompanied by social mobilization activities could contribute to improved routine immunization timeliness. This study assesses the impact of Kenya's introduction of pneumococcal conjugate vaccine (PCV) on the timeliness of routine childhood vaccination in two informal, urban settlements in Nairobi. Data collected from 2007 to 2015 as part of a demographic surveillance system were used to estimate annual vaccination delays of ≥ 4 weeks among children aged 12-23 months in the period before and after the introduction of PCV in Kenya. Binomial segmented regression models using generalized estimating equations examined the association between vaccine introduction and timeliness of routine immunization. Over half of all children vaccinated in the two urban areas received one or more doses ≥ 4 weeks after the recommended age. The timeliness of routine immunization showed slight improvements or nonsignificant changes during the years following PCV introduction compared with the preceding years (adjusted prevalence ratio [aPR]: 0.67, 95% CI: 0.45-0.99 for Bacille Calmette-Guerin receipt; aPR: 0.59, 95% CI: 0.41-0.83 for third dose Pentavalent receipt; aPR: 1.19, 95% CI: 0.99-1.42 for measles). However, as of 2015, delayed vaccination remained prevalent in children, particularly among the poorest residing in the settlements. Many sub-Saharan African countries have introduced new life-saving vaccines into their routine childhood immunization schedule. Additional evidence regarding the positive or neutral influence of new vaccine introduction on the performance of delivery systems provides further justification to sustain the inclusion of these more costly vaccines in the immunization schedule.

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

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

Review on immunogenicity, safety and social value of combined vaccines for children used both at home and abroad

Combined vaccines contain two or more antigens. Research suggested that combined vaccines could prevent multi diseases and reduce the frequency of vaccination. This article focus on combined vaccines for children used both at home and abroad, such as diphtheria-pertussis-tetanus vaccine (DTaP), measles-rubella-mumps vaccine (MMR), etc. and summarizes their immunogenicity, safety and social values, including benefits to families, vaccination workers and health services, to provide evidence for promoting the research, development and use of combined vaccines in China. We found that combined vaccines can not only ensure the immunogenicity and safety, but also give convenient and lower cost vaccination to families, and using combined vaccines can improve the work efficiency of vaccination workers, reduce the impact of the epidemic on immunization services and improve vaccination coverage and timeliness. At present, the promotion of combined vaccines in China is restricted by many technical bottlenecks, high prices, and low awareness among people. It is recommended that research on the safety, effectiveness and health economics of combined vaccines should be strengthened, and the value of combined vaccines should be scientifically evaluated; the public's awareness and trust in combined vaccines should be enhanced, as well as the development and application of multi-linked multivalent vaccines should be promoted. The government should improve regulations to assist the development and application of combined vaccines.

Timeliness of Early Childhood Vaccinations and Undervaccination Patterns in Montana

Early childhood vaccination rates are lower in rural areas than those in urban areas of the U.S. This study's objective is to quantify vaccine timeliness and the prevalence of undervaccination patterns in Montana and to measure the associations between timeliness and series completion by age 24 months. Using records from January 2015 to November 2019 in Montana's centralized immunization information system, days undervaccinated were calculated for the combined 7-vaccine series. Undervaccination patterns indicative of certain barriers to vaccination, including parental vaccine hesitancy, were identified. Using multivariable log-linked binomial regression, the association between timing of vaccine delay and not completing the combined 7-vaccine series by age 24 months was assessed. Analyses were conducted in March 2020-August 2020. Among 31,422 children, 38.0% received all vaccine doses on time; 24.3% received all doses, but some were received late; and 37.7% had not completed the combined 7-vaccine series. Approximately 18.7% had an undervaccination pattern suggestive of parental vaccine hesitancy, and 19.7% started all series but were missing doses needed for multidose series completion. Although falling behind on vaccinations at any age was associated with failing to complete the combined 7-vaccine series, being late at age 12-15 months had the strongest association (adjusted prevalence ratio=3.73, 95% CI=3.56, 3.91) compared with being on time at age 12-15 months. Fewer than 2 in 5 Montana children were fully vaccinated on time for the combined 7-vaccine series. To increase vaccination rates, initiatives to increase vaccine confidence and remind parents to complete vaccine series are needed.

Timeliness, completeness, and timeliness-and-completeness of serial routine vaccinations among rural children in Southwest China: A multi-stage stratified cluster sampling survey

IntroductionVaccination coverage is widely used as metric of vaccination programme performance. However, VPDs outbreaks were reported in areas with high vaccination coverage. Timeliness and completeness have been considered more important assessment indicators of routine vaccination than overall vaccination coverage, but little is known in rural China. This study aimed to assess the timeliness and completeness of serial routine vaccinations among children in rural Southwest China. MethodsA multi-stage stratified cluster survey was conducted among 1062 children aged 18–48 months in rural Guangxi. Vaccination status was obtained from child’s vaccination certificate. We calculated timely vaccination coverage, complete vaccination coverage, timely-and-complete vaccination coverage and 95% CI for routine vaccination through weighted estimation analysis. Weighted Kaplan-Meier analyses were applied to estimate the median delay periods for each dose of serial routine vaccines, including one-dose BCG, three-dose HepB, three-dose OPV, four-dose DTP, two-dose MCV, two-dose JEV and two-dose MPV-A. Complete coverage, and timely-and-complete coverage for combined 5-vaccine series were calculated. ResultsFor each dose of routine vaccines, overall vaccination coverages were over 90%, but timely vaccination coverage ranged from the lowest of 44.4% for JEV1 to the highest of 92.5% for MPV-A1. For multi-dose routine vaccines, complete vaccination coverages varied from the lowest of 92.9% for MCV to the highest of 100% for HepB, and timely-and-complete vaccination coverages were lower than 80%, ranging from the lowest of 30% for JEV to the highest of 77.2% for MPV-A. For combined 5-vaccine series, complete coverage was 77%, while timely-and-complete coverage was 12.1%. MPV-A1 had the longest median delay of 176 days, but BCG and HepB1 had the shortest of 1 day. ConclusionsThe overall coverages of serial routine vaccinations were high, but the timeliness and completeness were poor. Relevant agencies of vaccination service should address timeliness-and-completeness into the assessment indicators of routine vaccination service quality.

Using immunisation caregiver journey interviews to understand and optimise vaccination uptake: lessons from Sierra Leone

Quantitative and qualitative assessments have revealed diverse factors that influence the uptake of childhood immunisation services and shed light on reasons for vaccination delays and refusals. UNICEF and partner organisations...

Temporal Trends in Undervaccination: A Population-Based Cohort Study

Monitoring the trends in undervaccination, including that because of parental vaccine refusal or delay, can inform public health responses directed at improving vaccine confidence and vaccination coverage. A retrospective cohort study was conducted in the Vaccine Safety Datalink. The cohort included all children born in 2004-2017 with ≥3 well-child visits between ages 2 and 23 months. Using electronic health record-based vaccination data, the average days undervaccinated was calculated for each child. Undervaccination patterns were assessed through age 23 months. Temporal trends were inspected for inflection points and were analyzed using linear regression. Nested within the cohort study, a survey was conducted to compare parent reports of vaccine refusal or delay with observed vaccination patterns. Data were analyzed in 2020. The study cohort consisted of 808,170 children. The percentage of children with average days undervaccinated=0 (fully vaccinated, no delays) rose from a nadir of 47.1% for the birth year 2008 to 68.4% for the birth year 2017 (ptrend<0.001). The percentage with no vaccines rose from 0.35% for the birth year 2004 to 1.28% for the birth year 2017 (ptrend<0.001). Consistent vaccine limiting was observed in 2.04% for the birth year 2017. Omission of measles, mumps, and rubella vaccine peaked at 4.76% in the birth year 2007 and declined thereafter (ptrend<0.001). On the parent survey (response rate 60.2%), a high proportion of parents of the most undervaccinated children reported refusing or delaying vaccines. In a 14-year cohort study, vaccination timeliness has improved. However, the small but increasing number of children who received no vaccines by age 23 months warrants additional attention.

Immunisation Coverage Annual Report 2019.

Australian Immunisation Register data have been analysed for children aged < 5 years, focusing on changes in vaccination coverage at standard age milestones (12, 24 and 60 months) between 2018 and 2019. 'Fully vaccinated' coverage in 2019 increased by 0.1-0.4% at the three age milestones to 94.3% at 12 months, 90.2% at 24 months (in the context of additional antigens required at 24 months) and 94.2% at 60 months. Rotavirus vaccine coverage (2 doses) increased from 90.9% in 2018 to 91.9% in 2019. 'Fully vaccinated' coverage in Aboriginal and Torres Strait Islander (hereafter respectfully referred to as Indigenous) children increased by 0.5-1.1% in 2019, reaching 92.9% at 12 months, 88.9% at 24 months and 96.9% at the 60 months (2.7 percentage points higher than in children overall). Recorded influenza vaccination coverage in children aged 6 months to < 5 years increased by 11.4 percentage points to 42.7% in Indigenous children in 2019, and by 15.6 percentage points to 41.8% in children overall. Longstanding issues with timeliness of vaccination in Indigenous children persisted, although the disparity between Indigenous and non-Indigenous children in on-time coverage (within 30 days of due date), for vaccines due at 4 months of age, decreased from 10.4-10.7 to 9.6-9.8 percentage points between 2018 and 2019. The timeliness of 'fully vaccinated' coverage was also examined at earlier age milestones (3 months after due date of last scheduled vaccine) of 9, 15, 21 and 51 months, by Indigenous status, socioeconomic status and remoteness of area of residence. Coverage in children living in the least-advantaged residential area quintile was 2.6-2.7% lower than that for those living in the most-advantaged quintile at the 9-, 15- and 21-month milestones, although these disparities were 0.5-1.5 percentage points lower than in 2018. Coverage at the earlier milestones in Indigenous children in remote areas was 1.5-6.7% percentage points lower than that for Indigenous children in major cities and regional areas, although there were some improvements since 2018. Importantly, although Indigenous children had lower coverage for the second dose of measles-mumps-rubella vaccine at 24 months (92.7% versus 93.3% overall), coverage increased to 98.8% at 60 months; coverage was also high overall at 96.4%, above the 95% target critical to measles control. In conclusion, this report demonstrates continuing improvements across a range of immunisation indicators in Australia in 2019. However, some issues with timeliness persist, particularly in Indigenous and socioeconomically disadvantaged children. New coverage targets for earlier protection in the first 2 years of life may be indicated, along with a review of current 'fully vaccinated' assessment algorithms, particularly at the 60-month age milestone.

Immunisation Coverage Annual Report 2019

Australian Immunisation Register data have been analysed for children aged &lt; 5 years, focusing on changes in vaccination coverage at standard age milestones (12, 24 and 60 months) between 2018 and 2019. ‘Fully vaccinated’ coverage in 2019 increased by 0.1–0.4% at the three age milestones to 94.3% at 12 months, 90.2% at 24 months (in the context of additional antigens required at 24 months) and 94.2% at 60 months. Rotavirus vaccine coverage (2 doses) increased from 90.9% in 2018 to 91.9% in 2019. ‘Fully vaccinated’ coverage in Aboriginal and Torres Strait Islander (hereafter respectfully referred to as Indigenous) children increased by 0.5–1.1% in 2019, reaching 92.9% at 12 months, 88.9% at 24 months and 96.9% at the 60 months (2.7 percentage points higher than in children overall). Recorded influenza vaccination coverage in children aged 6 months to &lt; 5 years increased by 11.4 percentage points to 42.7% in Indigenous children in 2019, and by 15.6 percentage points to 41.8% in children overall. Longstanding issues with timeliness of vaccination in Indigenous children persisted, although the disparity between Indigenous and non-Indigenous children in on-time coverage (within 30 days of due date), for vaccines due at 4 months of age, decreased from 10.4–10.7 to 9.6–9.8 percentage points between 2018 and 2019. The timeliness of ‘fully vaccinated’ coverage was also examined at earlier age milestones (3 months after due date of last scheduled vaccine) of 9, 15, 21 and 51 months, by Indigenous status, socioeconomic status and remoteness of area of residence. Coverage in children living in the least-advantaged residential area quintile was 2.6–2.7% lower than that for those living in the most-advantaged quintile at the 9-, 15- and 21-month milestones, although these disparities were 0.5–1.5 percentage points lower than in 2018. Coverage at the earlier milestones in Indigenous children in remote areas was 1.5–6.7% percentage points lower than that for Indigenous children in major cities and regional areas, although there were some improvements since 2018. Importantly, although Indigenous children had lower coverage for the second dose of measles-mumps-rubella vaccine at 24 months (92.7% versus 93.3% overall), coverage increased to 98.8% at 60 months; coverage was also high overall at 96.4%, above the 95% target critical to measles control. In conclusion, this report demonstrates continuing improvements across a range of immunisation indicators in Australia in 2019. However, some issues with timeliness persist, particularly in Indigenous and socioeconomically disadvantaged children. New coverage targets for earlier protection in the first 2 years of life may be indicated, along with a review of current ‘fully vaccinated’ assessment algorithms, particularly at the 60-month age milestone.

Circulation of Bordetella pertussis in vaccinated Cambodian children: A transversal serological study

BackgroundThe Cambodia pertussis immunization schedule includes three doses given at age 6, 10 and 14 weeks using a whole-pertussis vaccine. No booster doses are included. Pertussis biological diagnosis is unavailable in Cambodia and its burden remains unclear. This study aimed to provide accurate data on pertussis serological status of Cambodian children and adolescents, and to evaluate vaccination timeliness. MethodsFully vaccinated children aged 3–15 years were recruited at the Rabies Prevention Center, Institut Pasteur in Cambodia, Phnom Penh. Capillary blood samples and information on pertussis vaccination history were collected. Anti-pertussis toxin (PT) IgG titers were quantified by ELISA. ResultsCompliance with the national immunization schedule was 95.1%. Initiation of vaccination after 8 weeks of age was observed for 29.0% of the children, but was less frequent in the youngest children (13.0%) compared with the oldest ones (46.4%). Rate of children exhibiting anti-PT IgG varied across age groups, and increased from 35.7% to 55.0% in 3–5 and 12–15 years age groups, respectively. ConclusionPertussis circulates among vaccinated Cambodian children and adolescents. These data support the need for public health authorities to strengthen pertussis surveillance and use local epidemiological data to make evidence-based decision for the establishment of an optimal vaccination strategy.

Vaccine coverage among children with epilepsy in two Canadian provinces: A Canadian immunization research network study

ObjectivesChildren with epilepsy are at increased risk of complications from vaccine-preventable infections, yet information on vaccine coverage in these children is scarce. We aimed to compare vaccine coverage among children with epilepsy to children without epilepsy. Study designWe conducted a retrospective cohort study including all 2005–2013 births in Manitoba and Ontario, Canada, creating two cohorts: 2-year-olds and 7-year-olds (followed to age 2 and 7 years). We split each cohort into epilepsy and non-epilepsy subcohorts. We assessed vaccination coverage based on provincial schedules and determined timeliness of MMR (measles, mumps, rubella) dose 1 (recommended at 12 months) and DTaP (diphtheria, tetanus, pertussis) dose 4 (recommended at 18 months). We used logistic regression to calculate adjusted odds ratios (aORs) of the association between epilepsy and vaccination, combining both provincial estimates using random effects meta-analysis. ResultsWe included 16,558 2-year-olds (Manitoba, 653; Ontario, 15,905) and 13,004 7-year-olds (Manitoba, 483; Ontario, 12,521) with epilepsy. At age 2 years, the aOR for up-to-date vaccination among children with versus without epilepsy was 0.9 (95% confidence interval 0.8–1.1); at age 7 years it was 1.0 (0.9–1.1). Infants diagnosed with epilepsy before age 6 months were less likely to be up-to-date at age 2 years (0.9; 0.8–0.9), although this difference disappeared by age 7 years. Vaccine timeliness was similar between children with and without epilepsy for MMR dose 1 and DTaP dose 4. ConclusionsOverall, this study suggests that children with epilepsy are not significantly under-vaccinated compared to their peers without epilepsy. As children with epilepsy are at a higher risk of complications from vaccine-preventable diseases, vaccination in children with epilepsy should be optimized, especially early in life, as these children may not be able to rely on herd protection.

Implementing WHO guidance on conducting and analysing vaccination coverage cluster surveys: Two examples from Nigeria.

In 2015, the World Health Organization substantially revised its guidance for vaccination coverage cluster surveys (revisions were finalized in 2018) and has since developed a set of accompanying resources, including definitions for standardized coverage indicators and software (named the Vaccination Coverage Quality Indicators-VCQI) to calculate them.-The current WHO vaccination coverage survey manual was used to design and conduct two nationally representative vaccination coverage surveys in Nigeria-one to assess routine immunization and one to measure post-measles campaign coverage. The primary analysis for both surveys was conducted using VCQI. In this paper, we describe those surveys and highlight some of the analyses that are facilitated by the new resources. In addition to calculating coverage of each vaccine-dose by age group, VCQI analyses provide insight into several indicators of program quality such as crude coverage versus valid doses, vaccination timeliness, missed opportunities for simultaneous vaccination, and, where relevant, vaccination campaign coverage stratified by several parameters, including the number of previous doses received. The VCQI software furnishes several helpful ways to visualize survey results. We show that routine coverage of all vaccines is far below targets in Nigeria and especially low in northeast and northwest zones, which also have highest rates of dropout and missed opportunities for vaccination. Coverage in the 2017 measles campaign was higher and showed less geospatial variation than routine coverage. Nonetheless, substantial improvement in both routine program performance and campaign implementation will be needed to achieve disease control goals.

Tracking Demographic Movements and Immunization Status to Improve Children's Access to Immunization (TDM-IAI): Protocol for a Field-Based Randomized Controlled Trial.

BackgroundIn Cameroon, the coverage, completeness, and timeliness of the Expanded Programme on Immunization (EPI) vaccines administration in children have remained heterogeneous and below the national and districts targets in several districts. In an effort to solve this problem, many interventions have been tested but none has shown significant improvement of the situation.ObjectiveThis trial aims to test whether involving Community Volunteers to assess children vaccination status and demographic movements and using recorded data to plan catch-up immunization sessions can improve children vaccination timeliness, completeness and coverage.MethodsCommunities of the Foumban Health district, West region of Cameroon will be selected and assigned to either intervention or control groups using a restricted randomization of 2. In the intervention group, one Community Volunteer per community will be trained to visit households and record EPI-targeted children in a register, record their demographic movements, and assess their immunization status monthly for a year. The information recorded will be snapped and sent to the competent health center immunization team through WhatsApp. These will be used to plan and implement monthly community catch up immunization sessions in collaboration with the community volunteer. In the control group, the routine immunization sessions will be conducted with health centers organizing either weekly vaccination sessions for communities situated not farther than 5 kilometers away from the health facility or monthly vaccination sessions in communities situated more than 5 kilometers away from the health center. Baseline, mid-term and end-line surveys will be conducted to assess and compare immunization coverage, timeliness, and completeness.ResultsFunded in 2018, data collection started in 2018 and has been completed. Data analysis and reporting are ongoing.ConclusionsThis trial is expecting to test an innovative approach to improving children’s immunization timeliness, completeness and coverage of immunization by tracking EPI targeted population vaccination status and denominator at household level and building collaboration between the community and health facilities vaccination teams to organize monthly community-based response vaccination sessions. This intervention is expected to improve children sustainable access to EPI vaccination as it offers assessing and responding to their immunization needs at monthly basis using low cost local human resources.Trial RegistrationPan African Clinical Trials Registry ID PACTR201808527428720; tinyurl.com/u058qnseInternational Registered Report Identifier (IRRID)DERR1-10.2196/21734

Timeliness of Vaccination among Children Attending Immunization Clinic at a Tertiary Hospital in South-East Nigeria.

Timely vaccination of children is one of the most cost-effective interventions that ensure childhood survival. We determined the proportion of children who received timely vaccination and examined the factors associated with timely receipt of Bacillus Calmette Guerin (BCG) and third dose of pentavalent vaccine (Penta 3). We conducted a cross-sectional survey among 599 caregivers-infant pair aged less than 24months, attending the immunization clinic of a tertiary hospital in Nigeria, selected using systematic sampling methods. Using a structured questionnaire, we access the proportion of children who received timely vaccination, the relationship between the timely receipt of BCG, Penta 3 vaccine and infant/caregiver characteristics was examined using chi-square and multiple logistic regression at a 5% level of significance. The mean age of the respondents was 30.1±5.0 years. The majority (73.8%) had attained tertiary education, lived in an urban setting (90.9%), had received antenatal care during pregnancy (99.3%) and was delivered in a hospital (97.0%). About half of the children (52.9%) were male. About 18% of the caregivers reported missing scheduled immunization visits, due to forgetfulness (18%), child illness (14%) and being busy (5%). About 88% (482) of the children got their BCG vaccines on time, 91.1% got timely OPV0, however, only 29.5% of the newborns got HBV0 within 24 hours of birth. Only 65.7% and 65.0% received the timely measles-containing vaccine and yellow fever vaccine. None of the factors examined predicted timely receipt of BCG and Penta 3 vaccines. Interventions that remind caregivers about the immunization schedules, could improve timely vaccination.

DTaP combination vaccine use and adherence: A retrospective cohort study

Despite universal recommendation of the 4-dose diphtheria, tetanus, and pertussis (DTaP) vaccine series, coverage and timeliness in the US remain suboptimal. DTaP-containing combination vaccines (i.e. quadrivalent and pentavalent) are presumed to improve vaccine coverage rates and timeliness, but research supporting this claim is limited. We sought to investigate the associations between DTaP-containing vaccine use and adherence to the recommended DTaP immunization schedule among children in the US. Using a large claims database, we identified privately insured children born between 2009 and 2016 that received ≥1 DTaP-containing vaccine and had ≥24 months of enrollment from birth, excluding those with DTaP vaccinations not aligned with approved dose indications. Children were classified by DTaP-containing vaccine receipt: combination vaccines only, stand-alone vaccines only, or a mixture of both. Outcome measures included: 1) completion of the 4-dose series and 2) timely receipt of doses. Outcomes were adjusted for gender, birth year, race, and socioeconomic status. The study cohort contained 412,441 children. Of these, 40.5% (167,084) received combination vaccines only, 14.9% (61,342) received stand-alone vaccines only, and 44.6% (184,015) received a mixture of both. Combination vaccine recipients were nearly 3 times as likely to complete the 4-dose series (OR 2.93 (95% CI: 2.88, 2.99)) and for all doses received, more than 4 times as likely to receive doses on time (OR 4.12 (4.04, 4.21), relative to stand-alone vaccine recipients. Significance disparities in adherence were also observed, where minorities were up to 30% less likely (OR 0.70 (0.68, 0.71)) to complete the 4-dose series and up to 27% less likely (OR 0.73 (0.72, 0.75)) to receive doses on time, relative to white children. Our findings demonstrated that adherence to the recommended DTaP immunization schedule was significantly greater among combination vaccine recipients, relative to stand-alone recipients. Further research is needed to investigate underlying causes of disparities in adherence.

Timeliness of childhood vaccinations in the Philippines

Timeliness of vaccinations is rarely part of monitoring in a routine immunization program. We reviewed infant immunization and conducted caregiver interviews in three regions in the Philippines from January to October 2016. We randomly selected thirty public health centers, one for each region. We defined timeliness of the receipt of antigen as within 4 weeks after the recommended age at vaccination. We assessed a total of 986 infants for timeliness of vaccination. The median age of receipt of vaccine was at 2.7 weeks (BCG), 10.1 weeks (Penta 1), and 21.7 weeks (Penta 3) compared to the recommended 0, 6, and 14 weeks of age, respectively. We found timely receipt only in 74.4% for BCG, 70.3% for Penta 1, and 39.1% for Penta 3 recipients. Thus, alongside declining immunization coverage, the infants in the Philippines had substantial delays in vaccine receipt.