Childhood Vaccination Schedule Research Articles

Hepatitis A virus infection and seroprevalence, Istanbul, Turkey, 2020-2023.

Hepatitis A infections continue to be a major global public health problem. The epidemiology and seroprevalence of hepatitis A virus (HAV) have important public health implications. This study aimed to retrospectively examine the hepatitis A cases and hepatitis A seroprevalence in our region in our hospital with the highest number of inpatient and outpatient cases in Istanbul. Determination of hepatitis A cases and seroprevalence. Cross-sectional. Tertiary care. A total of 39 385 individuals who were tested for Anti-HAV IgM and Anti-HAV Total (IgM+IgG) antibodies between May 2020 and September 2023 and were included in this study. Hepatitis A specific IgM and Total (IgM+IgG) antibodies were determined using the enzyme-linked immunosorbent assay method. Hepatitis A seroprevalence. 46 721. The study included a total of 46 721 samples from 39 385 individuals who were tested for hepatitis A serology. The median age of the 39385 individuals included in the study was 28 (interquartile range [IQR]; 22-46), with 58.74% being female and 4.07% (n=1163) being foreign nationals. Reactivity was detected in 91 of the 25 442 patients tested for HAV-IgM. Among these patients, 33 (0.13%) had acute hepatitis A infection, while 58 (0.23%) were considered false positives. Of the acute hepatitis A patients, 13 (0.09%) were women, and 22 (0.80%) were children. Acute hepatitis A was most commonly observed in the 6-9 and 15-18 age groups, with 7 cases each. The seroprevalence rate of hepatitis A was 67.23% among 33 683 individuals. Of those tested for HAV-Total, 13 132 (64.92%) were women, and 2533 (64.88%) were children. The lowest seroprevalence rate among age groups (35.91%) was in the 15-18 age year range, while the highest seroprevalence (98.34%) was detected in individuals aged 60 years and above. With a seroprevalence rate of 67.23%, our region is still considered a medium-endemic area for hepatitis A, and it is crucial to continue administering the HAV vaccine as currently included in the childhood vaccination schedule in our country. Additionally, the significantly low hepatitis A seropositivity, particularly in the 15-18 and 19-24 age groups, indicates the need to promote catch-up vaccination for young adults. Since our study covers a large population, it can serve as a guide regarding the serological status of hepatitis A in Istanbul. Since vaccination information for the study population was not available, it was not possible to distinguish between seropositivity due to vaccination or natural immunity. Despite being conducted in Istanbul, a cosmopolitan city, and in the largest city hospital, the results may not be representative of the entire country.

Correlation between vaccine hesitancy, vaccine reliability and perceptions of infectious diseases

Abstract Background Vaccine hesitancy is a delay in vaccine acceptance or refusal despite the availability of vaccination services. In recent years, the rise in vaccine hesitancy has attracted attention. This study aimed to evaluate the perception of vaccine hesitancy, vaccine safety, and infectious diseases among parents. Methods This cross-sectional study was conducted with 503 parents who applied to the pediatrics outpatient clinic of a university hospital. The questionnaire used in the study included questions on sociodemographic characteristics, factors related to vaccine hesitancy, The Vaccine Hesitancy Scale (VAS), the Vaccine Safety Scale (VSS), and the Perception Scale for Infectious Diseases (PPSID). Multivariate Linear Regression Analysis was used to find the variables associated with vaccine hesitancy. Results The mean age of the parents was 37.6±7.6 years. Parents’ scores on the ATS ranged from 17-85, with a mean score of 20.1±6.6 points. A moderate negative correlation was found between parents’ VAS and VSS scores, and between VAS and PPSID scores (r=-0.412, p < 0.001; r=-0.409, p < 0.001, respectively). According to the multivariate linear regression analysis the variables found to be associated with vaccine hesitancy, income status, maternal education level, child’s age group, having information about childhood vaccination schedule, child’s immunization status, the necessity of childhood vaccines, having sufficient information about the safety of vaccines, vaccine safety level, and infectious disease perception level were found to be significant predictors of vaccine hesitancy (F: 12,844, p ≤ 0.001, R2: 0.334). Conclusions This study determined that vaccine hesitancy was higher in families with lower income, who have not completed the schedule nor been vaccinated, doubt the necessity of vaccines to prevent infectious diseases, lack of knowledge about the reliability of vaccines, and whose children are still in primary school. Key messages • Health professionals have a critical role in reducing vaccine hesitancy. • It would be appropriate to plan face-to-face or online programs with parents.

Uncovering the health system burden of pneumococcal infections in adult and elderly populations

Abstract Background Health system resources dedicated to vaccination and infectious disease prevention are often directed towards infants and children, through extensive childhood vaccination schedules. This focus has led to the near eradication of several preventable childhood diseases and had positive impacts on population health, but despite this track record of success, the ability of our health systems to make vaccinations accessible throughout the full life course has been less consistent. This project aims to address this issue by providing new data about the burden that pneumococcal infections, which are vaccine-preventable, have on adult and elderly populations. Methods This research aims to uncover the health system burden of invasive pneumococcal disease and pneumococcal pneumonia at all levels of the health system in 5 EU countries (Austria, Belgium, France, Italy & Portugal). This involves a survey of managers and care providers working in hospitals, long-term care facilities, and primary care centres who may be affected by the health system impacts of pneumococcal infections. The survey covers several dimensions of health service delivery to collect a broad range of data on existing disruptions. The survey was translated into the study country languages and its formulation was further validated through interviews with experts in each study country to ensure that it can capture context-specific health system insights. The data collected through this survey will be further enhanced through a series of in-depth interviews before being synthesised, analysed and eventually published in a detailed report. Results Data collection begins as of 15 May 2024, and full results are expected to be published and available for the EPH Conference in November 2024. The results of this research will offer valuable evidence to public health professionals, health managers and policy-makers across Europe who are working to improve life-course access to pneumococcal vaccination. Key messages • Effective vaccination programmes for adult and elderly populations require expanding focus beyond childhood. • Data about the health system burden of pneumococcal infections in adult and elderly populations improves evidence-based decision-making and public health services.

Exploring the reasons for defaulting from childhood immunization: a qualitative study in Pakistan

BackgroundChildhood vaccination is widely recognized as the most effective means to prevent various diseases. However, a considerable amount of children still miss out on their vaccination schedules. Therefore, this study explores the reasons for defaulting from the expanded program on immunization in district Swat, Pakistan.MethodsA qualitative phenomenological approach was used. Data collection took place from March to September 2022. Thirty-six in-depth interviews were conducted with participants who had defaulter children. The collected qualitative data were analysed thematically to identify key patterns and themes related to the reasons for defaulting from childhood vaccination schedules.ResultsSix themes emerged, i.e., illness of the defaulter child at the scheduled time, perceived side effects of the vaccination, factors related to caregivers, myths and misconceptions, vaccinators attitudes and crowed vaccination centres, as well as poor immunization service arrangements. Four subthemes arose related to caregivers, such as lack of clear understanding about completion of vaccination, least priority for child’s vaccination, cultural restriction on mothers, and the loss of vaccination card.ConclusionAccording to the study’s findings, caregivers have their own perceptions regarding the non-completion of their children’s vaccination schedule. The childhood immunization defaulting arises from various factors including child illness, Adverse Events Following Immunization (AEFIs) concerns, misconceptions, improper injection techniques, and negative vaccinator attitudes. The vaccination completion rate may be increased if the concerns of the caregivers are appropriately addressed.

Cost minimization analysis of a hexavalent vaccine in Argentina

BackgroundArgentina currently uses a pentavalent vaccine containing diphtheria, tetanus, pertussis (whole cell), Haemophilus influenza type b and hepatitis B antigens, administered concomitantly with the inactivated polio vaccine (IPV) (DTwP-Hib-HB plus IPV) in its childhood vaccination schedule. However, hexavalent vaccines containing acellular pertussis antigens (DTaP-Hib-HB-IPV) and providing protection against the same diseases are also licensed, but are only available with a private prescription or for high-risk pre-term infants in the public health program. We analyzed the cost of switching from the current schedule to the alternative schedule with the hexavalent vaccine in Argentina, assuming similar levels of effectiveness.MethodsThe study population was infants ≤ 1 year of age born in Argentina from 2015 to 2019. The analysis considered adverse events, programmatic, logistic, and vaccine costs of both schemes from the societal perspective. The societal costs were disaggregated to summarize costs incurred in the public sector and with vaccination pre-term infants in the public sector. Costs were expressed in 2021 US Dollars (US$).ResultsAlthough the cost of vaccines with the alternative scheme would be US$39.8 million (M) more than with the current scheme, these additional costs are in large part offset by fewer adverse event-associated costs and lower programmatic costs such that the overall cost of the alternative scheme would only be an additional US$3.6 M from the societal perspective. The additional cost associated with switching to the alternative scheme in the public sector and with the vaccination of pre-term infants in the public sector would be US$2.1 M and US$84,023, respectively.ConclusionsThe switch to an alternative scheme with the hexavalent vaccine in Argentina would result in marginally higher vaccine costs, which are mostly offset by the lower costs associated with improved logistics, fewer separate vaccines, and a reduction in adverse events.

Immune response to co-administration of measles, mumps, and rubella (MMR), and yellow fever vaccines: a randomized non-inferiority trial among one-year-old children in Argentina

BackgroundIn yellow fever (YF) endemic areas, measles, mumps, and rubella (MMR), and YF vaccines are often co-administered in childhood vaccination schedules. Because these are live vaccines, we assessed potential immune interference that could result from co-administration.MethodsWe conducted an open-label, randomized non-inferiority trial among healthy 1-year-olds in Misiones Province, Argentina. Children were randomized to one of three groups (1:1:1): Co-administration of MMR and YF vaccines (MMR1YF1), MMR followed by YF vaccine four weeks later (MMR1YF2), or YF followed by MMR vaccine four weeks later (YF1MMR2). Blood samples obtained pre-vaccination and 28 days post-vaccination were tested for immunoglobulin G antibodies against measles, mumps, and rubella, and for YF virus-specific neutralizing antibodies. Non-inferiority in seroconversion was assessed using a -5% non-inferiority margin. Antibody concentrations were compared with Kruskal-Wallis tests.ResultsOf 851 randomized children, 738 were correctly vaccinated, had ≥ 1 follow-up sample, and were included in the intention-to-treat population. Non-inferior seroconversion was observed for all antigens (measles seroconversion: 97.9% in the MMR1YF1 group versus 96.3% in the MMR1YF2 group, a difference of 1.6% [90% CI -1.5, 4.7]; rubella: 97.9% MMR1YF1 versus 94.7% MMR1YF2, a difference of 3.3% [-0.1, 6.7]; mumps: 96.7% MMR1YF1 versus 97.9% MMR1YF2, a difference of -1.3% [-4.1, 1.5]; and YF: 96.3% MMR1YF1 versus 97.5% YF1MMR2, a difference of -1.2% [-4.2, 1.7]). Rubella antibody concentrations and YF titers were significantly lower following co-administration; measles and mumps concentrations were not impacted.ConclusionEffective seroconversion was achieved and was not impacted by the co-administration, although antibody levels for two antigens were lower. The impact of lower antibody levels needs to be weighed against missed opportunities for vaccination to determine optimal timing for MMR and YF vaccine administration.Trial RegistrationThe study was retrospectively registered in ClinicalTrials.gov (NCT03368495) on 11/12/2017.

Vaccine hesitancy among Ukrainian refugees.

On February 2022, Russia invaded Ukraine. Beyond Poland, Romania, Russia, several refugees reached Italy also. In the past, several factors contributed to low vaccination coverage in Ukraine and the occurrence of epidemic outbreaks. The purpose of our study was to analyze the main characteristics of Ukrainian refugees who accessed the Rozzano Vaccination Center (Italy), and the attitude towards proposed vaccinations. In March-July 2022, we conducted a cross-sectional study on Ukrainian refugees under the age of 18. On the basis of their vaccination certificates or antibody dosages, the doctor proposed to the parents (or legal guardians) any vaccinations to be carried out on the basis of the Italian childhood vaccination schedule. Refused or accepted vaccinations were registered and the data exported for statistical analysis. COVID-19 vaccination was excluded from the analysis. 27 refugees missed the appointment, so 79 Ukrainian refugees have been included in the study. Females represented the 51.90% of patients; the average age was 7.11 (sd 4.92) years. The most refused vaccinations were: HPV, MMR and men C. Significant differences due to age were found for Men C and Chickenpox acceptance. The efforts made to ensure complete care and to promote vaccination among refugees, offering them a complete evaluation of the vaccination status and the possibility of being vaccinated for free, seem to be insufficient to convince most refugees to get vaccinated.

Flexible analytic model to inform multi-stakeholder pediatric vaccine scheduling decisions

BackgroundPediatric immunization is important for preventing potentially life-threatening diseases in children. Over time, the number of recommended pediatric vaccines has increased and is likely to increase further as new vaccines are developed. Given the different number of doses for available vaccines and various constraints (e.g., the appropriate age for each dose of a vaccine or the time between doses), it is challenging to develop a recommended vaccination schedule or a catch-up schedule when a child falls behind on one or more vaccinations. MethodsWe developed an integer programming optimization model, enabled by Python programming and embedded into an Excel-based decision tool, to recommend childhood vaccination schedules or personalized catch-up schedules. The model recommends a vaccination schedule that balances the goal of being as close as possible to the clinically-indicated dosing schedules and the goal of minimizing clinic visits, and gives users the ability to trade off between these two goals. We illustrated the broad applicability of our proposed model with commonly-faced vaccine scheduling challenges in the United States. ResultsThe illustrative computational case study confirms our model’s ability to create personalized schedules based on each child’s age and vaccination history, and to adjust appropriately when a new vaccine becomes available. ConclusionsThe model presented in this paper fills the need for an easy-to-use tool to recommend vaccination schedules for de novo and catch-up purposes. It provides straightforward recommendations that can be easily used by physicians, is flexible to handle the requirements varying by region, and can be updated as new vaccines are approved for use.

Association of parent influenza vaccination and early childhood vaccinations using linked electronic health record data

IntroductionParent and child vaccination behavior is related for human papillomavirus (HPV) and flu vaccine. Thus, it is likely that parental vaccination status is also associated with their children’s adherence to guideline-concordant childhood vaccination schedules. We hypothesized that parent influenza (flu) vaccination would be associated with their child’s vaccination status at age two. MethodsWe used electronic health record data to identify children and linked parents seen in a community health center (CHC) within the OCHIN network (292 CHCs in 16 states). We randomly selected a child aged <2 years with ≥1 ambulatory visit between 2009-2018.Employing a retrospective, cohort study design, we used general estimating equations logistic regression to estimate the odds of a child being up-to-date on vaccinations based on their linked parents’ flu vaccination status. We adjusted for relevant parent and child covariates and stratified by mother only, father only, and two-parent samples. ResultsThe study included 40,007 family-units: mother only = 35,444, father only = 2,784, and two parents = 1,779. A higher percentage of children were fully vaccinated if their parent or parents received a flu vaccine. Children in the two-parent sample whose parents both received a flu vaccine had more than twice the odds of being fully vaccinated, and two and a half times the odds of being fully vaccinated except flu vaccine compared to children with two parents who did not receive a flu vaccine (covariate-adjusted odds ratio [aOR] = 2.39, 95% CI = 1.67, 3.43 and aOR = 2.54, 95% CI = 1.54, 4.19, respectively). ConclusionsParent flu vaccination is associated with routine child vaccination. Future research is needed to understand if this relationship persists over time and in different settings.

Attitudes towards mandatory vaccinations during the COVID-19 pandemic in Bulgaria

Abstract Background Vaccinations are an essential public health strategy to control preventable diseases. A much-discussed approach to increase coverage is mandatory vaccination; however, its legitimacy and effectiveness were put to question during the COVID-19 pandemic. As of March 1,2022, Bulgaria had one of Europe's lowest immunization coverage rates against COVID-19. Only 29.3% of Bulgarians had completed COVID-19 vaccination, compared to 71% in the EU and EEA, and the country ranked last in number of booster doses (9.9% vs 51.4 %). This study aims to investigate the public's attitudes toward proposed mandatory COVID-19 vaccination and toward the long-standing mandatory child immunization schedule in the context of the COVID-19 pandemic. Methods An online cross-sectional survey was conducted in April 2022 using a self-administered anonymous questionnaire to collect information on sociodemographic characteristics, vaccination status and attitudes toward mandatory vaccination to COVID-19 and the mandatory childhood immunization schedule. Results Out of 1433 reached respondents, 1200(84%) completed the survey. The largest relative share of respondents is between 35-44y-33.3%; 72.7% were women; mainly highly educated (50.8%), and vaccinated participants (59.3%). There is a significant and large difference between vaccinated and unvaccinated regarding the full support of mandatory COVID vaccinations (46.1% vs 1.8%), and regarding mandatory child vaccinations (77.9% vs 50.4%). Mandatory childhood vaccination schedules are supported by 88.7% of those in favor of obligatory COVID-19 vaccinations and 56% of those who oppose them (p &amp;lt; 0.001). Significance is preserved after adjustment for vaccination status. Conclusions Public health authorities need to develop well-organized vaccination campaigns in which accurate evidence-based information is adequately disseminated with respect to individuals’ autonomy. More research on the determinants of vaccination attitudes in Bulgaria is necessary. Key messages

Short report: Vaccine attitudes in the age of COVID-19 for a population of children with mitochondrial disease

BackgroundChildren with developmental disabilities are vulnerable to morbidity associated with COVID-19. AimsTo understand attitudes toward routine childhood vaccinations versus the COVID-19 vaccine in a population of families affected by mitochondrial disease (MtD), a form of developmental disability. Methods and proceduresAn online survey was administered via several advocacy groups for children with MtD. Outcomes and resultEighty-six percent of families reported being up to date with the childhood vaccine schedule and seventy percent reported that their affected child receives the annual flu shot. However, only fifty percent reported that the benefits of the COVID-19 vaccine outweighed the risk for their affected child. One quarter of families expressed concern that their child may become sick or deteriorate after the COVID-19 vaccine. In comparison to other routine childhood vaccines, families expressed less confidence in the COVID-19 vaccine. Conclusions and implicationsFamilies affected by this population of developmental disabilities are more comfortable with the vaccines included in the routine childhood immunization schedule than with the newly introduced COVID-19 vaccine, even despite this group’s vulnerability.

Calendario de vacunas en niños en un centro de atención primaria. Corrientes 2021.

Objective: Describe and identify the reasons why parents or guardians did not complete the childhood vaccination schedule in a Primary Health Care Center of the City of Corrientes in the year 2021. Methodology: Descriptive, cross-sectional study. Population: parents or guardians of children with incomplete schemes. Data collection through a survey validated in a pilot test. The data captured in a matrix were subjected to descriptive analysis. It was endorsed by the Ethics Committee. Results: The sample was integrated with 53 units of analysis. Mean age 28 years; 79% were mothers; 62% already had two or more children; 74% were single; 47% had not completed secondary or primary school; most were unemployed or received social plans. 66% thought that vaccines cured diseases; 89% prevented them and 89% thought they were safe. Sources of information: the medical and nursing team, 17% from family or friends, 30% on the internet or the media. In noncompliance reasons, the most frequent lack of vaccines (31%), parent or guardian work schedules (15%), infant diseases (10%). Conclusion: The information on vaccines was provided by the health team, families and the media. Although they claimed that they prevented diseases and were safe, many maintained that they cured diseases. Reasons for non-compliance were noted as lack of vaccines, work schedules of the interviewees and illnesses of the minor, time restrictions of the vaccination and those given by the pandemic.

Evaluation of Reasons for Partial Compliance and Non-compliance to the Routine Childhood Vaccination Schedule in Al-Russafa District

Objectives: To evaluate reasons for partial compliance and non-compliance to the routine childhood vaccination schedule in Al-Russafa district. Methodology: Descriptive study, using the evaluation approach, is carried throughout the present study to determine the reasons for the Routine Childhood Vaccination at health care sectors and primary health care centers at Al-Russafa District in Baghdad City, Convenient, non-probability, sample of (90) mother who are recruited from health care sectors at Al-Russafa District in Baghdad City. All mothers, who have participated in the study, have signed consent form for their agreements for the participation in the study. An interview-schedule is constructed for the purpose of the study. The study instrument is constructed through review of relevant literature. It is comprised of reasons responsible for partial compliance and Reasons for Non-compliance to the routine childhood vaccination schedule. Content validity and internal consistency reliability of the study instrument are determined through pilot study. Data are collected using the study instrument and the application of the structured interview as means of data collection. Data are analyzed through the application of the descriptive data analysis approach of frequency and percent. Results: The study depicts that mothers present different reasons for partial compliance and non-compliance for routine childhood vaccination schedule. Conclusion: Reasons for partial compliance for routine childhood vaccination schedule include that the child is ill and family problem including illness of mother, fear of side effects, the vaccination is postponed until another time in Al-Russafa districts. These reasons are identified as part of the obstacles, lack of information and lack of motivation reasons and reasons for non-compliance for routine childhood vaccination schedule include that the child is unvaccinated because of illness, fear of side effects after vaccination and the time for vaccination is not convenient in Al-Russafa districts in Baghdad City. These reasons are discovered as the main causes of the vaccination delay. Recommendations: The study recommends that routine childhood vaccination schedule should be seriously implemented and monitored. Further national studies can be conducted on such topic and on a wide-range scale. Keywords: Partial compliance, Non-compliance, Routine Childhood Vaccination Schedule

Looking ahead: Caregivers’ COVID-19 vaccination intention for children 5 years old and younger using the health belief model

COVID-19 vaccine hesitancy is a significant public health issue. While vaccines are not yet available for children, clinical trials are underway, and children will likely be an important factor in the U.S. reaching herd immunity. However, little research has been conducted to examine parents’ intention to vaccinate their young children for COVID-19. MethodAn online survey with a national U.S. sample of 682 primary caregivers of children under age six assessed variables associated with intention to accept the COVID-19 vaccine for their children from November 13, 2020, to December 8, 2020. ResultsCaregivers whose child received a recent influenza vaccine, as well as those with previous experience COVID-19, were more likely to express COVID-19 vaccination intention for their young child. Identifying as female was associated with lower COVID-19 vaccination intention, while identifying as Hispanic or Latino was associated with higher intention. Health Belief Model variables of perceived severity of COVID-19 for their child, as well as vaccine confidence, were positive predictors of COVID-19 vaccine intention and mediated the relationship between prior behavior, demographic variables, and intention. ConclusionsThe findings highlight the importance of early, proactive COVID-19 vaccination education efforts directed at caregivers, including those with young children. Vaccines for young children will likely become a necessary part of ending the pandemic’s impact in school settings. Operationally, COVID-19 vaccination may also become a part of childhood vaccination schedules. Understanding the beliefs and intentions of caregivers of young children before vaccinations are recommended for children will enable public health officials and medical practitioners to prepare in advance.

Pertussis in Asia: Recent country-specific data and recommendations

The Global Pertussis Initiative (GPI) Roundtable Meeting held in 2019, which preceded the COVID-19 pandemic, focused on the incidence, surveillance, and immunization practices for pertussis in the Asian region. Participants from China, India, Indonesia, Malaysia, Pakistan, Philippines, South Korea, Taiwan, and Thailand presented country-specific information on pertussis prevalence, diagnosis, surveillance, vaccine administration and schedules, maternal and neonatal disease rates, and policies and practice of vaccination during pregnancy. In recent years, many Asian countries have seen an increase in pertussis cases, although underreporting of the disease is a concern. Currently, most Asian countries have only passive surveillance for pertussis in place. There is a need for improved surveillance to determine the disease burden and justify vaccination policies and recommendations, such as essential vaccination, boosters, and vaccination during pregnancy. Better awareness of the disease in adolescents and adults is necessary, and infant and childhood vaccination schedules need to be improved in many countries. Differences between private versus public sector vaccination schedules and between whole-cell and acellular pertussis vaccines should continue to be examined. It can be anticipated that unmet needs in the prevention and management of pertussis will continue as the COVID-19 pandemic evolves and that key recommendations highlighted in this meeting report will be of ongoing importance.

The Childhood Vaccination Schedule and the Lack of Association With Type 1 Diabetes.

Safety studies assessing the association between the entire recommended childhood immunization schedule and autoimmune diseases, such as type 1 diabetes mellitus (T1DM), are lacking. To examine the association between the recommended immunization schedule and T1DM, we conducted a retrospective cohort study of children born between 2004 and 2014 in 8 US health care organizations that participate in the Vaccine Safety Datalink. Three measures of the immunization schedule were assessed: average days undervaccinated (ADU), cumulative antigen exposure, and cumulative aluminum exposure. T1DM incidence was identified by International Classification of Disease codes. Cox proportional hazards models were used to analyze associations between the 3 exposure measures and T1DM incidence. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were calculated. Models were adjusted for sex, race and ethnicity, birth year, mother's age, birth weight, gestational age, number of well-child visits, and study site. In a cohort of 584 171 children, the mean ADU was 38 days, the mean cumulative antigen exposure was 263 antigens (SD = 54), and the mean cumulative aluminum exposure was 4.11 mg (SD = 0.73). There were 1132 incident cases of T1DM. ADU (aHR = 1.01; 95% CI, 0.99-1.02) and cumulative antigen exposure (aHR = 0.98; 95% CI, 0.97-1.00) were not associated with T1DM. Cumulative aluminum exposure >3.00 mg was inversely associated with T1DM (aHR = 0.77; 95% CI, 0.60-0.99). The recommended schedule is not positively associated with the incidence of T1DM in children. These results support the safety of the recommended childhood immunization schedule.

Attitudes of Suburban Kansan Parents Regarding School-Required Immunizations and the Influences of the Coronavirus Pandemic.

IntroductionUnderstanding suburban, Kansas parental attitudes and adherence of recommended childhood vaccination schedules adopts a new level of importance in the era of the SARS-CoV-2019 (COVID-19) pandemic. With hopes for release of a safe and effective COVID-19 vaccine underway, understanding parental perception of vaccines is important to design successful vaccination interventions.MethodsA web-based, cross-sectional survey was administered to approximately 900 parents in Johnson County, Kansas during the summer of 2020. Pearson chi square and Mann-Whitney U tests were utilized to assess the attitudes of Kansas parents towards a potential addition of the influenza vaccine to the required list for K-12 students and furthermore, their general perception of vaccinations, and the impact of COVID-19 on those beliefs.ResultsA total of 179 parents responded. Fifty-one percent (n = 92) were in favor of adding the influenza vaccine to the mandatory list (Pro-Addition). Anti-Addition parents had significantly higher levels of distrust (2.1, p < 0.001) and were significantly more concerned about vaccine adverse effects. When presented with a hypothetical situation in which a “safe and effective” COVID-19 vaccine was available, 24% of Anti-Addition parents indicated they would receive the vaccine or obtain it for their children (21 people, p < 0.001).ConclusionsKansas suburban parents were split on their attitudes towards the addition of the influenza vaccine to the required list for children and the effects of the pandemic. Follow-up qualitative studies of Anti-Addition parents are critical for successful vaccine distribution and coverage in the communities.

Detecting adherence to the recommended childhood vaccination schedule from user-generated content in a US parenting forum.

Vaccine hesitancy is considered as one of the leading causes for the resurgence of vaccine preventable diseases. A non-negligible minority of parents does not fully adhere to the recommended vaccination schedule, leading their children to be partially immunized and at higher risk of contracting vaccine preventable diseases. Here, we leverage more than one million comments of 201,986 users posted from March 2008 to April 2019 on the public online forum BabyCenter US to learn more about such parents. For 32% with geographic location, we find the number of mapped users for each US state resembling the census population distribution with good agreement. We employ Natural Language Processing to identify 6884 and 10,131 users expressing their intention of following the recommended and alternative vaccination schedule, respectively RSUs and ASUs. From the analysis of their activity on the forum we find that ASUs have distinctly different interests and previous experiences with vaccination than RSUs. In particular, ASUs are more likely to follow groups focused on alternative medicine, are two times more likely to have experienced adverse events following immunization, and to mention more serious adverse reactions such as seizure or developmental regression. Content analysis of comments shows that the resources most frequently shared by both groups point to governmental domains (.gov). Finally, network analysis shows that RSUs and ASUs communicate between each other (indicating the absence of echo chambers), however with the latter group being more endogamic and favoring interactions with other ASUs. While our findings are limited to the specific platform analyzed, our approach may provide additional insights for the development of campaigns targeting parents on digital platforms.

1399. Parental Perceptions of the Childhood Vaccination Schedule and Combination Vaccines in the United States (US)

BackgroundTen different vaccine series are recommended by the US Advisory Committee on Immunization Practices from birth to 18 months. Combination vaccines can reduce the number of injections and visits required to complete the schedule in a timely manner. There is limited current information on parents’ perception of the vaccine schedule and combination vaccines.MethodsAn online survey was completed by 100 parents who had at least one child under 2 years, were involved in vaccination decisions, and had accompanied their child to a vaccination appointment. Parents who reported not ever vaccinating their children were excluded. Parents’ perception of, and adherence to, the recommended schedule, communication with providers, and knowledge of combination vaccines were collected. Descriptive analyses were performed.ResultsNinety-six percent of parents (mean age=30.7 years; range 19.0-50.0; 91% white) reported their provider as a source of vaccination information, followed by internet searches (63%), family and friends (45%). Most (84%) followed all their provider’s recommendations and trusted the information given to them (87%). State day care and pre-school requirements influenced vaccination decisions for nearly 80% of parents.Over 80% of parents thought it is important to protect against diseases covered by the vaccination schedule. One-third had at some time asked to delay or not administer vaccines; depending on the vaccine, up to 50% ultimately had their child vaccinated as recommended. Top reasons for delaying vaccination were to avoid crying and pain from multiple injections (82%), and the concern that too many vaccines would overwhelm the immune system (64%). Top reasons for refusal were religious views (57%) and the belief that the vaccine was not needed (52%).On average, parents would accept their child receiving 3 injections in one visit. Most parents were aware of combination vaccines (84%); however, one-third reported that their child had not received, or they were unaware of their child receiving, a combination vaccine.ConclusionProviders are in a strong position to influence vaccination decisions by parents. Whereas parents are motivated to avoid the pain of multiple injections, many are unaware that their children are receiving combination vaccines.DisclosuresTanaz Petigara, PhD, Merck & Co., Inc. (Employee, Shareholder) Xinyi Ng, PhD, Merck & Co., Inc. (Consultant) Ya-Ting Chen, PhD, Merck & Co., Inc. (Employee, Shareholder) Jyoti Aggarwal, MHS, Merck & Co., Inc. (Consultant) Jenna Bhaloo, MPH, Merck & Co., Inc. (Consultant) Michelle Goveia, MD, Merck & Co., Inc (Employee, Shareholder) David Johnson, MD, MPH, Sanofi Pasteur (Employee, Shareholder) Gary S. Marshall, MD, GlaxoSmithKline (Consultant, Scientific Research Study Investigator)Merck (Consultant, Scientific Research Study Investigator)Pfizer (Consultant, Scientific Research Study Investigator)Sanofi Pasteur (Consultant, Grant/Research Support, Scientific Research Study Investigator, Honorarium for conference lecture)Seqirus (Consultant, Scientific Research Study Investigator)

Using emergency department syndromic surveillance to investigate the impact of a national vaccination program: A retrospective observational study.

BackgroundRotavirus infection is a common cause of gastroenteritis in children worldwide, with a high mortality burden in developing countries, particularly during the first two years of life. Rotavirus vaccination was introduced into the United Kingdom childhood vaccination schedule in July 2013, with high coverage (>90%) achieved by June 2016. We used an emergency department (ED) syndromic surveillance system to assess the impact of the rotavirus vaccination programme, specifically through the demonstration of any immediate and continuing impact on ED gastroenteritis visits in England.MethodsThis retrospective, observational study used syndromic surveillance data collected from 3 EDs in the two years before (July 2011—June 2013) and 3 years post (July 2013—June 2016) introduction of rotavirus vaccination. The weekly levels of ED visits for gastroenteritis (by age group and in total) during the period before rotavirus vaccination was first described alongside the findings of laboratory surveillance of rotavirus during the same period. An interrupted time-series analysis was then performed to demonstrate the impact of rotavirus vaccination introduction on gastroenteritis ED visit levels.ResultsDuring the two years before vaccine introduction ED visits for gastroenteritis in total and for the 0–4 years age group were seen to rise and fall in line with the seasonal rotavirus increases reported by laboratory surveillance. ED gastroenteritis visits by young children were lower in the three years following introduction of rotavirus vaccination (reduced from 8% of visits to 6% of visits). These attendance levels in young children (0-4years) remained higher than in older age groups, however the previously large seasonal increases in children were greatly reduced, from peaks of 16% to 3–10% of ED visits per week.ConclusionsED syndromic surveillance demonstrated a reduction in gastroenteritis visits following rotavirus vaccine introduction. This work establishes ED syndromic surveillance as a platform for rapid impact assessment of future vaccine programmes.