Development and evaluation of virtual simulation games to increase the confidence and self-efficacy of healthcare learners in vaccine communication, advocacy, and promotion.

BACKGROUND: Although healthcare providers (HCPs) are the most trusted source of vaccine information, there is a paucity of easily accessible, multidisciplinary educational tools on vaccine communication for them. Virtual simulation games (VSGs) are innovative yet accessible and effective tools in healthcare education. The objectives of our study were to develop VSGs to increase HCP confidence and self-efficacy in vaccine communication, advocacy, and promotion, and evaluate the VSGs' effectiveness using a pre-post self-assessment pilot study. METHODS: A multidisciplinary team of experts in medicine, nursing, pharmacy, and simulation development created three VSGs for HCP learners focused on addressing conversations with vaccine hesitant individuals. We evaluated the VSGs with 24 nursing students, 30 pharmacy students, and 18 medical residents who completed surveys and 6-point Likert scale pre-post self-assessments to measure changes in their confidence and self-efficacy. RESULTS: There were no significant differences in baseline confidence and self-efficacy across the three HCP disciplines, despite varied levels of education. Post-VSG confidence and self-efficacy (median: 5) were significantly higher than pre-VSG (median: 4-5) for all three HCP disciplines (P ≤ 0.0005), highlighting the effectiveness of the VSGs. Medical residents reported significantly lower post-VSG confidence and self-efficacy than nursing and pharmacy learners despite completing the most significant amount of education. CONCLUSIONS: Following the completion of the VSGs, learners in medicine, nursing, and pharmacy showed significant improvement in their self-assessed confidence and self-efficacy in holding vaccine conversations. The VSGs as an educational tool, in combination with existing clinical immunization training, can be used to increase HCP confidence and engagement in vaccine discussions with patients, which may ultimately lead to increased vaccine confidence among patients.

Characterizing the Pain Experience of Children With Acute Gastroenteritis Based on Identified Pathogens.

OBJECTIVES: Pain is common with acute gastroenteritis (AGE) yet little is known about the severity associated with specific enteropathogens. We sought to explore the correlation of pain severity with specific enteropathogens in children with AGE. METHODS: Participants were prospectively recruited by the Alberta Provincial Pediatric EnTeric Infection TEam at 2 pediatric emergency departments (EDs) (December 2014-August 2018). Pain was measured (by child and/or caregiver) using the 11-point Verbal Numerical Rating Scale. RESULTS: We recruited 2686 participants; 46.8% (n = 1256) females, with median age 20.1 months (interquartile range 10.3, 45.3). The mean highest pain scores were 5.5 [standard deviation (SD) 3.0] and 4.2 (SD 2.9) in the 24 hours preceding the ED visit, and in the ED, respectively. Prior to ED visit, the mean highest pain scores with bacterial detection were 6.6 (SD 2.5), compared to 5.5 (SD 2.9) for single virus and 5.5 (SD 3.1) for negative stool tests. In the ED, the mean highest pain scores with bacterial detection were 5.5 (SD 2.7), compared to 4.1 (SD 2.9) for single virus and 4.2 (SD 3.0) for negative stool tests. Using multivariable modeling, factors associated with greater pain severity prior to ED visit included older age, fever, illness duration, number of diarrheal or vomiting episodes in the preceding 24 hours, and respiratory symptoms, but not enteropathogen type. CONCLUSION: Children with AGE experience significant pain, particularly when the episode is associated with the presence of a bacterial enteric pathogen. However, older age and fever appear to influence children's pain experiences more than etiologic pathogens.

Parents' perceptions on COVID-19 vaccination as the new routine for their children ≤ 11 years old.

Canadian children 5-11 years old became eligible for COVID-19 vaccination on November 19, 2021, with eligibility for younger children expected later. We aimed to descriptively assess parents' COVID-19 vaccine intentions and acceptability of future doses, including co-administration and annual vaccination for their children. We conducted a cross-sectional Canadian online survey of parents from October 14-November 12, 2021, just prior to authorization of the pediatric formulation of the BNT162b2 COVID-19 vaccine for children aged 5-11 years. We assessed parents' intention to vaccinate their children aged 5-11 years, 2-4 years, and 6-23 months; reasons for their intention; and preferences for delivery and access to vaccines. Of 1129 parents, 56% intended to vaccinate their child aged 5-11 years against COVID-19; intentions were lower for children aged 6-23 months (41.9%) and 2-4 years (45.4%). Most parents who intended to vaccinate supported co-administration with routine (61.1%) or influenza (55.4%) vaccines, administration at school (63.6%), receipt of booster doses of COVID-19 vaccine (57.8%), and annual vaccination (56.4%) for their child. Despite parents' high COVID-19 vaccination uptake for themselves (88.8%), intentions for children aged 5-11 years was low. Currently, 56.9% of Canadian children aged 5-11 years have received one dose of a COVID-19 vaccine, and only 37.1% are fully vaccinated. Given that intentions for children <5 years was lower than those 5-11 years, we can also expect low uptake in this group. Parents' preferences regarding delivery and access to COVID-19 vaccination should be considered by public health officials when planning vaccination strategies for children.

Measuring inequalities in COVID-19 vaccination uptake and intent: results from the Canadian Community Health Survey 2021.

BACKGROUND: By July 2021, Canada had received enough COVID-19 vaccines to fully vaccinate every eligible Canadian. However, despite the availability of vaccines, some eligible individuals remain unvaccinated. Differences in vaccination uptake can be driven by health inequalities which have been exacerbated and amplified by the pandemic. This study aims to assess inequalities in COVID-19 vaccination uptake and intent in adults 18 years or older across Canada by identifying sociodemographic factors associated with non-vaccination and low vaccination intent using data drawn from the June to August 2021 Canadian Community Health Survey (CCHS). METHODS: The CCHS is an annual cross-sectional and nationally representative survey conducted by Statistics Canada, which collects health-related information. Since September 2020, questions about the COVID-19 pandemic are asked. Adjusted logistic regression models were fitted to examine associations between vaccination uptake or intent and sociodemographic and health related variables. Region, age, gender, level of education, Indigenous status, visible minority status, perceived health status, and having a regular healthcare provider were considered as predictors, among other factors. RESULTS: The analysis included 9,509 respondents. The proportion of unvaccinated was 11%. Non-vaccination was associated with less than university education (aOR up to 3.5, 95% CI 2.1-6.1), living with children under 12 years old (aOR 1.6, 95% CI 1.1-2.4), not having a regular healthcare provider (aOR 1.6, 95% CI 1.1-2.2), and poor self-perceived health (aOR 1.8, 95% CI 1.3-2.4). Only 5% of the population had low intention to get vaccinated. Being unlikely to get vaccinated was associated with the Prairies region (aOR 2.2, 95% CI 1.2-4.1), younger age groups (aOR up to 4.0, 95% CI 1.3-12.3), less than university education (aOR up to 3.8, 95% CI 1.9-7.6), not being part of a visible minority group (aOR 3.0, 95% CI 1.4-6.4), living with children under 12 years old (aOR 1.8, 95% CI 1.1-2.9), unattached individuals (aOR 2.6, 95% CI 1.1-6.1), and poor self-perceived health (aOR 2.0, 95% CI 1.3-2.9). CONCLUSIONS: Disparities were observed in vaccination uptake and intent among various sociodemographic groups. Awareness of inequalities in COVID-19 vaccination uptake and intent is needed to determine the vaccination barriers to address in vaccination promotion strategies.

Transition to endemic: acceptance of additional COVID-19 vaccine doses among Canadian adults in a national cross-sectional survey.

BACKGROUND: Additional doses of COVID-19 vaccine have been proposed as solutions to waning immunity and decreased effectiveness of primary doses against infection with new SARS-CoV-2 variants. However, the effectiveness of additional vaccine doses relies on widespread population acceptance. We aimed to assess the acceptance of additional COVID-19 vaccine doses (third and annual doses) among Canadian adults and determine associated factors. METHODS: We conducted a national, cross-sectional online survey among Canadian adults from October 14 to November 12, 2021. Weighted multinomial logistic regression analyses were used to identify sociodemographic and health-related factors associated with third and annual dose acceptance and indecision, compared to refusal. We also assessed influences on vaccine decision-making, and preferences for future vaccine delivery. RESULTS: Of 6010 respondents, 70% reported they would accept a third dose, while 15.2% were undecided. For annual doses, 64% reported acceptance, while 17.5% were undecided. Factors associated with third dose acceptance and indecision were similar to those associated with annual dose acceptance and indecision. Previous COVID-19 vaccine receipt, no history of COVID-19 disease, intention to receive an influenza vaccine, and increasing age were strongly associated with both acceptance and indecision. Chronic illness was associated with higher odds of acceptance, while self-reported disability was associated with higher odds of being undecided. Higher education attainment and higher income were associated with higher odds of accepting additional doses. Minority first language was associated with being undecided about additional doses, while visible minority identity was associated with being undecided about a third dose and refusing an annual dose. All respondents reported government recommendations were an important influence on their decision-making and identified pharmacy-based delivery and drop-in appointments as desirable. Co-administration of COVID-19 and influenza vaccines was viewed positively by 75.5% of the dose 3 acceptance group, 12.3% of the undecided group, and 8.4% of the refusal group. CONCLUSIONS: To increase acceptance, targeted interventions among visible minority and minority language populations, and those with a disability, are required. Offering vaccination at pharmacies and through drop-in appointments are important to facilitate uptake, while offering COVID-19/influenza vaccine co-administration may have little benefit among those undecided about additional doses.

Sociodemographic Disparities in COVID-19 Vaccine Uptake and Vaccination Intent in Canada.

Introduction: This study's objective was to examine sociodemographic disparities in COVID-19 vaccine uptake and vaccination intent in the Canadian provinces by identifying factors associated with vaccine uptake in seniors prioritized for vaccination at the time of the survey and vaccination intent in all adults. Data and methods: A cross-sectional survey of Canadian adults was conducted in all provinces from mid-April to mid-May 2021. In addition to sociodemographic characteristics, respondents (n=10,678) provided information on their COVID-19 vaccination status or their intent to get vaccinated. Logistic regression models were fitted using sociodemographic factors as explanatory variables and vaccination status (unvaccinated vs at least one dose) or vaccination intent (unlikely versus likely or already vaccinated) as outcomes. To account for vaccine prioritization groups, multiple regression models were adjusted for province of residence, age, Indigenous identity and health care worker status. Results: Seniors with a lower household income (less than $60,000) and those living in smaller communities (fewer than 100,000 inhabitants) had higher odds of being unvaccinated. Among Canadian adults, the odds of being unlikely to get vaccinated were higher for males (adjusted odds ratio [AOR] 1.3), individuals younger than 60 (AOR between 3.3 and 5.1), non-health care workers (AOR 3.3), those with less than a high school education (AOR 3.4) or a household income of less than $30,000 (AOR 2.7) and individuals who do not identify as South Asian, Chinese, Black, Filipino, Arab, Latin American, Southeast Asian, West Asian, Korean or Japanese (AOR 1.7). Interpretation: COVID-19 vaccine uptake (80%) and vaccination intent (95%) were high among Canadians; however, relative disparities were observed among specific groups. Continued efforts targeted toward these groups are essential in reducing potential inequity in access or service provision.

Association of COVID-19 Vaccination in Pregnancy With Adverse Peripartum Outcomes.

Importance: There is limited comparative epidemiological evidence on outcomes associated with COVID-19 vaccination during pregnancy; monitoring pregnancy outcomes in large populations is required. Objective: To evaluate peripartum outcomes following COVID-19 vaccination during pregnancy. Design, Setting, and Participants: Population-based retrospective cohort study in Ontario, Canada, using a birth registry linked with the provincial COVID-19 immunization database. All births between December 14, 2020, and September 30, 2021, were included. Exposures: COVID-19 vaccination during pregnancy, COVID-19 vaccination after pregnancy, and no vaccination. Main Outcomes and Measures: Postpartum hemorrhage, chorioamnionitis, cesarean delivery (overall and emergency cesarean delivery), admission to neonatal intensive care unit (NICU), and low newborn 5-minute Apgar score (<7). Linear and robust Poisson regression was used to generate adjusted risk differences (aRDs) and risk ratios (aRRs), respectively, comparing cumulative incidence of outcomes in those who received COVID-19 vaccination during pregnancy with those vaccinated after pregnancy and those with no record of COVID-19 vaccination at any point. Inverse probability of treatment weights were used to adjust for confounding. Results: Among 97 590 individuals (mean [SD] age, 31.9 [4.9] years), 22 660 (23%) received at least 1 dose of COVID-19 vaccine during pregnancy (63.6% received dose 1 in the third trimester; 99.8% received an mRNA vaccine). Comparing those vaccinated during vs after pregnancy (n = 44 815), there were no significantly increased risks of postpartum hemorrhage (incidence: 3.0% vs 3.0%; aRD, -0.28 per 100 individuals [95% CI, -0.59 to 0.03]; aRR, 0.91 [95% CI, 0.82-1.02]), chorioamnionitis (0.5% vs 0.5%; aRD, -0.04 per 100 individuals [95% CI, -0.17 to 0.09]; aRR, 0.92 [95% CI, 0.70-1.21]), cesarean delivery (30.8% vs 32.2%; aRD, -2.73 per 100 individuals [95% CI, -3.59 to -1.88]; aRR, 0.92 [95% CI, 0.89-0.95]), NICU admission (11.0% vs 13.3%; aRD, -1.89 per 100 newborns [95% CI, -2.49 to -1.30]; aRR, 0.85 [95% CI, 0.80-0.90]), or low Apgar score (1.8% vs 2.0%; aRD, -0.31 per 100 newborns [95% CI, -0.56 to -0.06]; aRR, 0.84 [95% CI, 0.73-0.97]). Findings were qualitatively similar when compared with individuals who did not receive COVID-19 vaccination at any point (n = 30 115). Conclusions and Relevance: In this population-based cohort study in Ontario, Canada, COVID-19 vaccination during pregnancy, compared with vaccination after pregnancy and with no vaccination, was not significantly associated with increased risk of adverse peripartum outcomes. Study interpretation should consider that the vaccinations received during pregnancy were primarily mRNA vaccines administered in the second and third trimester.

Attribution of Pediatric Acute Gastroenteritis Episodes and Emergency Department Visits to Norovirus Genogroups I and II.

BACKGROUND: Norovirus is a leading cause of acute gastroenteritis. With vaccines in development, population-based estimates of norovirus burden are needed to identify target populations, quantify potential benefits, and understand disease dynamics. METHODS: We estimated the attributable fraction (AF) for norovirus infections in children, defined as the proportion of children testing positive for norovirus whose gastroenteritis was attributable to norovirus. We calculated the standardized incidence and emergency department (ED) visit rates attributable to norovirus using provincial gastroenteritis visit administrative data. RESULTS: From 3731 gastroenteritis case patients and 2135 controls we determined that the AFs were 67.0% (95% confidence interval [CI], 31.5%-100%) and 91.6% (88.8%-94.4%) for norovirus genogroups I (GI) and II (GII), respectively. Norovirus GII AF varied by season but not age. We attributed 116 episodes (95% CI, 103-129) and 59 (51-67) ED visits per 10 000 child-years to norovirus GII across all ages, accounting for 20% and 18% of all medically attended gastroenteritis episodes and ED visits, respectively. CONCLUSIONS: In children, a large proportion of norovirus GII detections reflect causation, demonstrating significant potential for norovirus GII vaccines. Seasonal variation in the norovirus GII AF may have implications for understanding the role asymptomatic carriage plays in disease dynamics.

Characterizing Pain in Children with Acute Gastroenteritis Who Present for Emergency Care.

OBJECTIVE: To characterize the pain experienced by children with acute gastroenteritis (AGE) in the 24 hours before emergency department (ED) presentation. Secondary objectives included characterizing ED pain, discharge recommendations, overall analgesic use, and factors that influenced analgesic use and pain severity. STUDY DESIGN: A prospective cohort was recruited from 2 pediatric EDs (December 2014 to September 2017). Eligibility criteria included <18 years of age, AGE (≥3 episodes of diarrhea or vomiting in the previous 24 hours), and symptom duration <7 days at presentation. RESULTS: We recruited 2136 patients, median age 20.8 months (IQR 10.4, 47.4) and 45.8% (979/2136) female. In the 24 hours before enrollment, most caregivers reported moderate (28.6% [610/2136, 95% CI 26.7-30.5]) or severe (46.2% [986/2136, CI 44.0-48.3]) pain for their child. In the ED, they reported moderate (31.1% [664/2136, 95% CI 29.1-33.1]) or severe ([26.7% [571/2136, 95% CI 24.9-28.7]) pain; analgesia was provided to 21.2% (452/2131). The most common analgesics used in the ED were acetaminophen and ibuprofen. At discharge, these were also most commonly recommended. Factors associated with greater analgesia use in the ED were high pain scores during the index visit, having a primary care physician, earlier presentation to emergency care, fewer diarrheal episodes, presence of fever, and hospitalization at index visit. CONCLUSIONS: Most caregivers of children presenting to the ED with AGE reported moderate or severe pain, both before and during their visit. Future research should focus on the development of effective, safe, and timely pain management plans.

The impact of varicella vaccination on paediatric herpes zoster epidemiology: a Canadian population-based retrospective cohort study.

The impact of universal varicella vaccination on herpes zoster (HZ) risk in unvaccinated and vaccinated children, and its long-term influence on HZ epidemiology, remains unknown. We conducted a retrospective cohort study using population-based administrative health data for children born between 1993 and 2018 (n = 924,124). We calculated age-specific cumulative HZ incidence rates by vaccination status for cohorts born before (1993-1999) and after (2000-2018) programme implementation; results were used to calculate relative risk of HZ by age group, vaccination status and vaccine availability period. Annual HZ incidence rates were calculated for 1993-2018. HZ risk was higher among unvaccinated children compared to vaccinated children across age groups; 64% higher before universal vaccination (RR: 0.36, 95% CI: 0.33, 0.39), and 32% higher after universal vaccination (RR: 0.68, 95% CI: 0.64, 0.73). Among unvaccinated children, HZ risk was 60% lower after vaccine programme implementation (RR: 0.40, 95% CI: 0.38, 0.43). Two-dose receipt corresponded with a 41% lower risk of HZ compared to one-dose receipt (RR: 0.59, 95% CI: 0.53, 0.65). Crude annual HZ incidence rates declined 64% after programme implementation, with decreases observed across age groups. Universal varicella vaccination programme implementation corresponds to decreased paediatric HZ incidence across age groups, in both vaccinated and unvaccinated individuals. Results from this study can be used to help inform varicella vaccination programme decision-making in other countries.

A Web Application About Herd Immunity Using Personalized Avatars: Development Study.

BACKGROUND: Herd immunity or community immunity refers to the reduced risk of infection among susceptible individuals in a population through the presence and proximity of immune individuals. Recent studies suggest that improving the understanding of community immunity may increase intentions to get vaccinated. OBJECTIVE: This study aims to design a web application about community immunity and optimize it based on users' cognitive and emotional responses. METHODS: Our multidisciplinary team developed a web application about community immunity to communicate epidemiological evidence in a personalized way. In our application, people build their own community by creating an avatar representing themselves and 8 other avatars representing people around them, for example, their family or coworkers. The application integrates these avatars in a 2-min visualization showing how different parameters (eg, vaccine coverage, and contact within communities) influence community immunity. We predefined communication goals, created prototype visualizations, and tested four iterative versions of our visualization in a university-based human-computer interaction laboratory and community-based settings (a cafeteria, two shopping malls, and a public library). Data included psychophysiological measures (eye tracking, galvanic skin response, facial emotion recognition, and electroencephalogram) to assess participants' cognitive and affective responses to the visualization and verbal feedback to assess their interpretations of the visualization's content and messaging. RESULTS: Among 110 participants across all four cycles, 68 (61.8%) were women and 38 (34.5%) were men (4/110, 3.6%; not reported), with a mean age of 38 (SD 17) years. More than half (65/110, 59.0%) of participants reported having a university-level education. Iterative changes across the cycles included adding the ability for users to create their own avatars, specific signals about who was represented by the different avatars, using color and movement to indicate protection or lack of protection from infectious disease, and changes to terminology to ensure clarity for people with varying educational backgrounds. Overall, we observed 3 generalizable findings. First, visualization does indeed appear to be a promising medium for conveying what community immunity is and how it works. Second, by involving multiple users in an iterative design process, it is possible to create a short and simple visualization that clearly conveys a complex topic. Finally, evaluating users' emotional responses during the design process, in addition to their cognitive responses, offers insights that help inform the final design of an intervention. CONCLUSIONS: Visualization with personalized avatars may help people understand their individual roles in population health. Our app showed promise as a method of communicating the relationship between individual behavior and community health. The next steps will include assessing the effects of the application on risk perception, knowledge, and vaccination intentions in a randomized controlled trial. This study offers a potential road map for designing health communication materials for complex topics such as community immunity.

Systematic review searches must be systematic, comprehensive, and transparent: a critique of Perman et al.

A high quality systematic review search has three core attributes; it is systematic, comprehensive, and transparent. The current over-emphasis on the primacy of systematic reviews over other forms of literature review in health research, however, runs the risk of encouraging publication of reviews whose searches do not meet these three criteria under the guise of being systematic reviews. This correspondence comes in response to Perman S, Turner S, Ramsay AIG, Baim-Lance A, Utley M, Fulop NJ. School-based vaccination programmes: a systematic review of the evidence on organization and delivery in high income countries. 2017; BMC Public Health 17:252, which we assert did not meet these three important quality criteria for systematic reviews, thereby leading to potentially unreliable conclusions. Our aims herein are to emphasize the importance of maintaining a high degree of rigour in the conduct and publication of systematic reviews that may be used by clinicians and policy-makers to guide or alter practice or policy, and to highlight and discuss key evidence omitted in the published review in order to contextualize the findings for readers. By consulting a research librarian, we identified limitations in the search terms, the number and type of databases, and the screening methods used by Perman et al. Using a revised Ovid MEDLINE search strategy, we identified an additional 1016 records in that source alone, and highlighted relevant literature on the organization and delivery of school-based immunization program that was omitted as a result. We argue that a number of the literature gaps noted by Perman et al. may well be addressed by existing literature found through a more systematic and comprehensive search and screening strategy. We commend both the journal and the authors, however, for their transparency in supplying information about the search strategy and providing open access to peer reviewer and editor's comments, which enabled us to understand the reasons for the limitations of that review.

Risk of febrile seizures after first dose of measles-mumps-rubella-varicella vaccine: a population-based cohort study.

BACKGROUND: The combination measles-mumps-rubella-varicella (MMRV) vaccine currently used in Canada (Priorix-Tetra) may increase the risk of febrile seizures relative to the separate vaccines (MMR and varicella) previously administered. We determined the risk of febrile seizure after the first dose of MMRV, as well as any additional risk for children at high risk for seizures because of pre-existing medical conditions. METHODS: In this retrospective, population-based cohort study, we compared the risk of seizures after the first dose of MMRV with the risk after same-day administration of separate MMR and varicella vaccines (MMR+V) in children 12 to 23 months of age in the province of Alberta. We deterministically linked vaccination data to health service utilization data for seizures. We used Poisson regression, with adjustment for age and calendar year, to determine the risk for the full cohort and for high-risk children. RESULTS: The risk of seizures 7 to 10 days after vaccination was twice as high with MMRV as with MMR+V (relative risk [RR] 1.99, 95% confidence interval [CI] 1.30-3.05). The excess absolute risk of seizures was 3.52 seizures per 10 000 doses of MMRV relative to MMR+V. In high-risk children, the risk was not differentially higher for MMRV (RR 1.30, 95% CI 0.60-2.79). INTERPRETATION: Despite an increased risk of febrile seizures following MMRV (compared with MMR+V), the absolute level of risk was small. Policy-makers need to balance these findings with the potential benefits of administering the combination vaccine or determine whether the choice of vaccine rests with clinicians and/or parents.

The pot calling the kettle black: the extent and type of errors in a computerized immunization registry and by parent report.

BACKGROUND: Accurate classification of children's immunization status is essential for clinical care, administration and evaluation of immunization programs, and vaccine program research. Computerized immunization registries have been proposed as a valuable alternative to provider paper records or parent report, but there is a need to better understand the challenges associated with their use. This study assessed the accuracy of immunization status classification in an immunization registry as compared to parent report and determined the number and type of errors occurring in both sources. METHODS: This study was a sub-analysis of a larger study which compared the characteristics of children whose immunizations were up to date (UTD) at two years as compared to those not UTD. Children's immunization status was initially determined from a population-based immunization registry, and then compared to parent report of immunization status, as reported in a postal survey. Discrepancies between the two sources were adjudicated by review of immunization providers' hard-copy clinic records. Descriptive analyses included calculating proportions and confidence intervals for errors in classification and reporting of the type and frequency of errors. RESULTS: Among the 461 survey respondents, there were 60 discrepancies in immunization status. The majority of errors were due to parent report (n = 44), but the registry was not without fault (n = 16). Parents tended to erroneously report their child as UTD, whereas the registry was more likely to wrongly classify children as not UTD. Reasons for registry errors included failure to account for varicella disease history, variable number of doses required due to age at series initiation, and doses administered out of the region. CONCLUSIONS: These results confirm that parent report is often flawed, but also identify that registries are prone to misclassification of immunization status. Immunization program administrators and researchers need to institute measures to identify and reduce misclassification, in order for registries to play an effective role in the control of vaccine-preventable disease.

Patterns in COVID-19 vaccination among children aged 5-11 years in Alberta, Canada: Lessons for future vaccination campaigns.

Objectives: In Alberta, Canada, the COVID-19 vaccination program for children aged 5-11 years was launched on November 26, 2021. Our objectives were to determine the cumulative vaccine coverage, stratified by age, during the first thirteen months of vaccine availability, and investigate factors associated with vaccine uptake. Study design: This retrospective cohort study used population-based administrative health data. Methods: We determined cumulative vaccine coverage among 5-11 year olds, stratified by year of age, during the first thirteen months of vaccine availability and used a modified Poisson regression to evaluate factors associated with vaccine uptake. Results: Of 377,103 eligible children, 44.8 % (n = 168,761) received one or more doses of COVID-19 vaccine during the study period (9.7 % received only one dose, while 35.1 % received 2 doses). Almost 90 % of initial doses were received within the first two months of vaccine availability. We found a step-wise relationship between increasing child age and higher vaccine coverage. Conclusions: Plateaued vaccine uptake indicates a need to adapt programmatic efforts to encourage parents to act on positive vaccination intentions, and reach the large contingent of parents who have reported that they remain undecided. In order to promote vaccine uptake, messaging around vaccine safety and need should be tailored to child age, rather than uniformly applied across the 5-11 year age range.

Human papillomavirus vaccine coverage among immigrant adolescents in Alberta: a population-based cohort study.

BACKGROUND: Little is known about human papillomavirus (HPV) vaccination among immigrant children in Canada. We conducted a study in Alberta, Canada to assess HPV vaccine coverage among school-aged immigrant children compared with non-immigrant children. METHODS: This cohort study analysed population-based linked administrative health data to measure HPV vaccine coverage for 346 749 school-aged children, including 31 656 immigrants. Coverage was examined at 12 y of age from 2008 to 2018 for females, and from 2014 to 2018 for males and both sexes combined; vaccine series completion was considered receipt of three doses, with initiation (one or more dose) as a supplementary analysis. Multivariable logistic regression examined the association of vaccine coverage with migration status, adjusting for sociodemographic variables. RESULTS: Between 2014 and 2018, HPV vaccination coverage among immigrant children at age 12 y was significantly higher (52.58%) compared with non-immigrant children (47.41%). After controlling for place of residence, income quintile, biological sex and year, immigrant children had 1.10 greater odds (95% confidence interval 1.07 to 1.14) of receiving three doses of HPV vaccine compared with non-immigrant children. Immigrants from Asia and Africa had the highest coverage (60.25-68.78%), while immigrants from North America, Oceania and South America had the lowest coverage (39.97-48.36%). CONCLUSIONS: It is encouraging that immigrant children had higher HPV vaccine coverage compared with non-immigrants. Among immigrants, routine immunization promotion strategies should be tailored based on the country of origin.

Sex Differences in the Immunogenicity and Efficacy of Seasonal Influenza Vaccines: A Meta-analysis of Randomized Controlled Trials.

Background: Sex impacts individuals' response to vaccination. However, most vaccine studies do not report these differences disaggregated by sex. The aim of this study was to assess sex differences in the immunogenicity and efficacy of influenza vaccine. Methods: We performed a meta-analysis using phase 3 randomized controlled trial data conducted between 2010 and 2018. Using hemagglutination inhibition antibody titers for each strain, differences in geometric mean ratios (GMRs) were calculated by sex. Risk ratios (RRs) comparing seroconversion proportions were pooled for females and males using random-effects models. Vaccine efficacy (VE) was assessed. Data were analyzed by age group (18-64 vs ≥65 years). Results: A total of 33 092 healthy adults from 19 studies were included for immunogenicity analysis, and 6740 from 1 study for VE. Whereas no sex differences in immunogenicity were found in adults <65 years old, older females had a significantly greater chance to seroconvert compared to older males for all strains: RRH1N1 = 1.17 [95% confidence interval {CI}, 1.12-1.23]; RRH3N2 = 1.09 [95% CI, 1.05-1.14]; RRVictoria = 1.23 [95% CI, 1.14-1.31]; RRYamagata = 1.22 [95% CI, 1.14-1.30]. GMRs were also higher in older females for all strains compared to older males. VE in preventing laboratory-confirmed influenza was higher in older females compared to older males with VEs of 27.32% (95% CI, 1.15%-46.56%) and 6.06% (95% CI, -37.68% to 35.90%), respectively. Conclusions: Our results suggest a higher immunogenicity and VE in females compared to males in older adults. These differences in immunogenicity and VE support the disaggregation of vaccine data by sex in clinical trials and observational studies. Clinical Trials Registration: CRD42018112260.

Impact of maternal depression and anxiety on immunization status of children: a prospective cohort study.

BACKGROUND: Maternal depression and anxiety can have a detrimental impact on birth outcomes and healthy child development; there is limited knowledge on its influence on immunization schedule adherence. Therefore, the objectives of this study were to determine the impact of maternal depression and anxiety in the perinatal period on prolonged vaccine delay of childhood vaccines. METHODS: In this prospective cohort study, we analyzed linked survey and administrative data of 2,762 pregnant women in Calgary, Alberta, Canada. Data were collected at two time-points: prenatal (< 25 weeks of gestation) and postpartum (4 months postpartum). We used multivariable logistic regression to examine the association between depression and anxiety with prolonged immunization delay, adjusting for covariates. RESULTS: In multivariable analysis, maternal depression at either time point was not associated with prolonged delay for DTaP-IPV-Hib (OR 1.16, 95% CI 0.74-1.82), MMR/MMRV (OR 1.03, 95% CI 0.72-1.48), or all routine childhood vaccines combined (OR 1.32, 95% CI 0.86-2.04). Maternal anxiety at either time point was also not associated with prolonged delayed for DTaP-IPV-Hib (OR 1.08, 95% CI 0.77-1.53), MMR/MMRV (OR 1.07, 95% CI 0.82-1.40), or all vaccines combined (OR 1.00, 95% CI 0.80-1.26). In both the depression and anxiety models, children of Canadian-born mothers had higher odds of prolonged delay, as did those with low-income mothers. CONCLUSION: Health care providers can be reassured that maternal depression and anxiety do not appear to influence maternal commitment to routine immunization. Findings suggested that low income and household moves may influence adherence to vaccine schedules and health care providers may want to provide anticipatory guidance to these families.

Intersecting Inequities in COVID-19 Vaccination: A Discourse Analysis of Information Use and Decision-Making Among Ethnically Diverse Parents in Canada.

BACKGROUND: Little is known about how intersecting social privilege and disadvantage contribute to inequities in COVID-19 information use and vaccine access. This study explored how social inequities intersect to shape access to and use of COVID-19 information and vaccines among parents in Canada. METHODS: We conducted semi-structured interviews on COVID-19 vaccination information use with ethnically diverse parents of children ages 11 to 18 years from April to August 2022. We purposefully invited parents from respondents to a national online survey to ensure representation across diverse intersecting social identities. Five researchers coded transcripts in NVivo using a discourse analysis approach informed by intersectionality. Our analysis focused on use of vaccine information and intersecting privileges and oppressions, including identifying with equity-denied group(s). RESULTS: Interview participants (N = 48) identified as ethnically diverse non-Indigenous (n = 40) and Indigenous (n = 8) Peoples from seven Canadian provinces. Racialized minority or Indigenous participants reflected on historical and contemporary events of racism from government and medical institutions as barriers to trust and access to COVID-19 information, vaccines, and the Canadian healthcare system. Participants with privileged social locations showed greater comfort in resisting public health measures. Despite the urgency to receive COVID-19 vaccines, information gaps and transportation barriers delayed vaccination among some participants living with chronic medical conditions. CONCLUSION: Historicization of colonialism and ongoing events of racism are a major barrier to trusting public health information. Fostering partnerships with trusted leaders and/or healthcare workers from racialized communities may help rebuild trust. Healthcare systems need to continuously implement strategies to restore trust with Indigenous and racialized populations.

"I try to take all the time needed, even if i do not have it!": Knowledge, attitudes, practices of perinatal care providers in canada about vaccination.

Objective: Successful clinical conversations about vaccination in pregnancy (pertussis, COVID-19, and influenza) are key to improving low uptake rates of both vaccination in pregnancy and infancy. The purpose of this study was to understand Canadian perinatal care providers' knowledge, attitudes, and practices around vaccination in pregnancy. Methods: Qualitative interviews with 49 perinatal care providers (nurse practitioner, general practitioner, registered nurse, registered midwife, obstetrician-gynecologist, and family physicians) in 6 of 13 provinces and territories were deductively coded using directed content analysis [1] and analyzed according to key themes. Results: Participants detailed their professional training and experiences, patient community demographics, knowledge of vaccines, views and beliefs about vaccination in pregnancy, and attitudes about vaccine counselling. Providers generally described having a good range of information sources to keep vaccine knowledge up to date. Some providers lacked the necessary logistical setups to administer vaccines within their practice. Responses suggest diverging approaches to vaccine counselling. With merely hesitant patients, some opted to dig in and have more in-depth discussions, while others felt the likelihood of persuading an outright vaccine-refusing patient to vaccinate was too low to be worthwhile. Conclusion: Provider knowledge, attitudes, and practices around vaccination varied by professional background. To support perinatal providers' knowledge and practices, clinical guidelines should detail the importance of vaccination relative to other care priorities, emphasize the positive impact of engaging hesitant patients in vaccine counselling.