Julie Bettinger

Faculty of Medicine

Research Classification

Public and population health

Research Interests

Epidemiology

Vaccination

Infectious diseases

Health Promotion

Community Health / Public Health

Infectious disease epidemiology

vaccine clinical trials

Vaccine hesitancy

vaccine programs

vaccine safety

Relevant Thesis-Based Degree Programs

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Affiliations to Research Centres, Institutes & Clusters

BC Children's Hospital Research Institute

Biography

Research Methodology

Graduate Student Supervision

Doctoral Student Supervision

Dissertations completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest dissertations.

Do fathers care? Measuring mother's and father's perceptions of father's involvement in caring for young children in South Africa (2017)

Fathers can be an important source of support for children. However, in South Africa, many children do not reside with their biological father and little is known about fathers’ involvement in children’s care. A questionnaire that reliably measures fathers’ involvement and is adaptable to varied residential arrangements would facilitate future population-level research. We explored whether children who reside with their biological father have better health than children whose fathers live elsewhere. We also assessed whether a questionnaire adapted from surveys in the United States would reliably measure South African fathers’ involvement in caring for infants. With data from the 1998 Demographic and Health Survey, we used multilevel logistic regression to estimate associations between father-child co-residence status and four child health outcomes: breastfeeding for ≥6 months; immunization completeness; recent acute respiratory infection; and recent diarrhea. We found that children with non-co-resident fathers were not at higher risk of these health outcomes. As part of a separate longitudinal cohort study in the Western Cape, we had a sample of mothers complete questionnaires about their infants’ fathers’ care involvement when infants were 2 weeks, 16 weeks and 6 months old. Using Item Response Theory models we estimated the distribution of the fathers’ levels of involvement in five hypothetically distinct modes of care. We used total information functions to assess the precision of father involvement estimates. Most fathers were reportedly spending time with infants, doing routine care activities and providing financially. Fewer fathers were involved in important care decisions or doing household chores. For most fathers in the sample, the questionnaire gave precise estimates of involvement in three modes of care: Accessibility, Direct Caregiving, and Practical Support for Mother. In contrast, items measuring Material Provisioning and Responsibility gave imprecise estimates for the majority of fathers. Our findings reinforce existing evidence that co-residence status is an inadequate proxy for care involvement. Future population-level research into fathers’ influences on children’s health should directly measure fathers’ care practices. With further validation, the questionnaire assessed in this study could be used to measure the more direct modes of infant care.

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The pattern and pathways of infectious morbidity in South African HIV exposed uninfected infants (2016)

Background: Universal infant morbidity risk factors (poor birth outcomes, suboptimal breastfeeding, poverty) occur more frequently in HIV exposed uninfected (HEU) than HIV unexposed uninfected (HUU) infants. HEU infants’ unique exposures, including in utero exposure to HIV products and maternal immune compromise, may potentiate HEU infants’ infectious morbidity risk. The primary objective was to determine whether HEU infants experience greater infectious morbidity than HUU infants through HIV exposure-specific pathways beyond universal infant morbidity risk factors. Methods: This prospective cohort study identified low risk HIV-infected and HIV-uninfected mothers and their term newborns from a single community midwife unit in Kraaifontein, South Africa. The primary outcome, at least one infectious cause hospitalization or death before six months of age, was classified according to modified WHO case-definitions and compared between HEU and HUU infants. Complete outcome determination on all infants was possible through linkage with the electronic provincial hospital administration system and mortality registry. Adjusted odds ratios (aOR) were calculated by multivariable logistic regression including stratified analyses conditioned on breastfeeding. Results: One hundred and seventy six (94 HEU, 82 HUU) mother-infant pairs were included. HIV-infected mothers were older (median 27.8 vs. 24.7 years, p0.01) and HEU infants less often breastfed (35/94 (37%) vs. 81/82 (99%), p0.001). The groups were similar on maternal education, antenatal course, household characteristics, birth weight, gestational age and immunizations. Incidence rate ratio of all-cause sick clinic visits in HEU compared to HUU infants was 0.82 (95% CI 0.58,1.16). The primary outcome occurred in 17 (18%) HEU and 10 (12%) HUU infants (p=0.38), giving an aOR of 1.45 (95% CI 0.44,4.55). In stratified analysis comparing only infants with any breastfeeding, HEU infants had an aOR for a very severe infectious cause hospitalization or death of 4.2 (95% CI 1.00,19.2, p=0.05). Seven of 17(41%) HEU and 1/10 (10%) HUU primary outcome events occurred after 90 days of age (p=0.07). Conclusion: Amongst term infants with similar social circumstances, a higher probability of very severe infectious morbidity was observed in breastfed HEU compared to breastfed HUU infants. HEU infant risk may be driven through HIV exposure-specific pathways unrelated to universal infant morbidity risk factors.

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Master's Student Supervision

Theses completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest theses.

Seasonal influenza vaccine safety in children and pregnant people: cross-sectional analysis from 2013/2014 to 2019/2020 (2022)

Introduction: The Canadian National Vaccine Safety (CANVAS) network collects seasonal influenza vaccine safety data from adults and children across Canada each year. Health events are evaluated between a vaccinated group and an unvaccinated group using data from online surveys. This thesis aims to describe the rate of severe health events and the most severe symptoms following seasonal influenza vaccination compared to an unvaccinated group of children and pregnant people. In addition, it aims to determine the agreement between symptoms reported in the online survey and a follow-up telephone report. Methods: Uncorrelated data from the CANVAS network were analyzed from 2013/2014 to 2019/2020. The outcome of interest was a severe health event that prevented/stopped daily activities, missed school, or required medical consultation. Incidence rate ratios and logistic regressions were conducted for both groups of interest to determine the association between vaccination status and severe health events. The sensitivity, specificity, and kappa estimate were calculated to determine the agreement for the most severe symptom, diagnosis, and treatment. Results: The unadjusted rate ratio for severe health events in children who received the inactivated influenza vaccine (IIV) compared to unvaccinated children was 1.22 (1.10, 1.34). However, no differences were observed in children who received the live attenuated influenza vaccine (LAIV) compared to an unvaccinated child group. The adjusted odds ratio (OR) for severe health events in children who received IIV compared to unvaccinated children was 1.11 (1.00, 1.25), and 1.11 (0.95, 1.29) in children who received LAIV compared to unvaccinated children. The agreement between child responses in the self-report online survey and the telephone report was moderate-to-high in both vaccinated and unvaccinated participants combined. The unadjusted rate ratio for severe health events in vaccinated pregnant people compared to unvaccinated pregnant people was 1.00 (0.64, 1.58). The adjusted OR for severe health events in vaccinated compared to unvaccinated pregnant people was 0.95 (0.59, 1.53). Conclusion: The findings show no association between the seasonal influenza vaccine and severe health events in children and pregnant people in Canada. There was moderate to high agreement of child responses between the online survey and the telephone report.

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Investigating the association of receipt of seasonal influenza vaccine with occurrence of anesthesia/paresthesia, headaches and generalized convulsive seizures for all ages, Canada 2012/13-2016/17 (2019)

Introduction/background: Concern about adverse events following immunization (AEFI) is frequently cited by both those who receive vaccines and those who decline to receive vaccines. Neurological adverse events are especially concerning. Our aim is to detect associations for occurrence of anesthesia/paresthesia (numbness, tingling, pins and needles, decreased sensation, or burning sensations anywhere in the body), severe headaches, and generalized convulsive seizures (GCS) in the presence and absence of seasonal influenza vaccination.Methods: Data were analyzed from the Canadian National Vaccine Safety Network that annually collects safety data during the seasonal influenza vaccination campaign. Events were self-reported and prevented daily activity, led to absenteeism, or required medical attention. Controls were previous year vaccinees; events in controls were collected prior to the start of influenza vaccination each year. Total sample size for investigating anesthesia/paresthesia was 107,565 from 2012-2016, and 97,420 for investigating severe headaches and GCS from 2013-2016. Multivariable logistic regression was used to determine the association between seasonal influenza vaccination and occurrence of anesthesia/paresthesia or severe headaches adjusted for gender, age group, reporting center, and year. Fisher’s exact test was used to measure risk of occurrence of GCS.Results: 104 (0.10%) participants reported anesthesia/paresthesia; 63 (0.09%) versus 41 (0.11%) in vaccinees and controls, respectively. Severe headaches were reported by 1,361 (1.40%) participants; 907 (1.48%) versus 454 (1.26%) in vaccinees and controls, respectively. Adjusted OR of anesthesia/paresthesia among those with seasonal influenza vaccination was 0.89 (95% CI = 0.60, 1.32), and of severe headaches was 1.21 (95% CI = 1.08, 1.36). No specific vaccine product was associated with this increased risk. Three participants were identified with GCS; difference in proportions between groups was not statistically significant (p = 0.301).Conclusions: Results are reassuring on the safety of seasonal influenza vaccines. Anesthesia/paresthesia was rare (≥ 0.01 and 0.1%), while severe headaches were common (≥ 1% and 10%), and GCS was a very rare ( 0.01%) AEFI. No associations were found for anesthesia/paresthesia and GCS. There was a higher risk of severe headaches that merits counseling at the time of vaccination. Ongoing monitoring is crucial to maintaining confidence in seasonal influenza vaccination safety.

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