Perspectives on COVID-19 vaccination and vaccine passports in a diverse urban adolescent population: a youth participatory mixed-methods study

Purpose Disparities in youth COVID-19 vaccine acceptance and uptake have been documented in several countries, yet few studies have explored the attitudes and perceptions underlying vaccine-related decision-making among adolescent populations with unique socio-cultural, environmental, and/or structural contexts that may influence vaccine uptake. Methods This study used data from surveys and semi-structured interviews collected between January and March 2022 as part of an ongoing community-based research project in two ethnoculturally diverse, lower-income neighbourhoods of Montreal, Canada. Youth researchers designed and conducted interviews with unvaccinated adolescents and thematic analysis was employed to explore attitudes and perceptions underlying vaccine-related decisions and opinions about vaccine passports. Survey data were used to describe sociodemographic and psychological determinants of COVID-19 vaccination. Results Among 315 survey participants aged 14-17 years, most (74%) were fully vaccinated against COVID-19. Prevalence ranged from 57% among Black adolescents to 91% among South and/or Southeast Asian adolescents (34% difference, 95% CI: 20-49). Qualitative and quantitative findings highlighted several misconceptions about the safety, effectiveness, and necessity of COVID-19 vaccines and adolescents' desire for trusted sources of information to address their concerns. Vaccine passports likely increased uptake;yet adolescents were strongly resistant to the policy, and, for some, it may have fuelled distrust of government and scientific institutions. Conclusion Strategies that increase the trustworthiness of institutions and foster genuine partnership with underserved youth may improve vaccine confidence and help ensure an effective, pro-equity recovery from COVID-19.

Pre-Omicron seroprevalence, seroconversion, and seroreversion of infection-induced SARS-CoV-2 antibodies among a cohort of children and teenagers in Montréal, Canada.

OBJECTIVES: To use serological testing to assess the pre-Omicron seroprevalence, seroconversion, and seroreversion of infection-induced SARS-CoV-2 antibodies in children and adolescents in Montréal, Canada. DESIGN: This analysis is from a prospective cohort study of children aged 2-17 years (at baseline) that included blood spots for antibody detection. The serostatus of participants was determined by enzyme-linked immunosorbent assays using the receptor-binding domain from the spike protein and the nucleocapsid protein as antigens. We estimated seroprevalence, seroconversion rates, and the likelihood of seroreversion at 6 months and 1 year. RESULTS: The baseline (October 2020 to April 2021) seroprevalence was 5.8% (95% confidence interval [CI] 4.8-7.1), which increased to 10.5% (May to September 2021) and 11.0% (November 2021 to March 2022) for the respective follow-ups (95% CI 8.6-12.7; 95% CI 8.8-13.5). The crude rate of seroconversion over the study period was 12.8 per 100 person-years (95% CI 11.0-14.7). The adjusted hazard rates of seroconversion by child characteristics showed higher rates in children who were female, whose parent identified as a racial or ethnic minority, and in households with incomes in the lowest tercile of our study population. The likelihood of remaining seropositive at 6 months was 68% (95% CI 60-77%) and dropped to 42% (95% CI 32-56%) at 1 year. CONCLUSION: Serological studies continue to provide valuable contributions for infection prevalence estimates and help us better understand the dynamics of antibody levels after infection.

Using human-centred design to tackle COVID-19 vaccine hesitancy for children and youth: a protocol for a mixed-methods study in Montreal, Canada.

INTRODUCTION: To successfully combat COVID-19 vaccine hesitancy and increase uptake, research has demonstrated that interventions are most effective when tailored to meet local needs through active engagement and co-development with communities. This mixed-methods project uses a human-centred design (HCD) approach to understand local perspectives of COVID-19 vaccine hesitancy and develop strategies to enhance vaccine confidence for children and adolescents. METHODS AND ANALYSIS: Project ECHO (Étude Communautaire sur l'Hésitation vaccinale contre la COVID-19) combines population-based surveys of parents and adolescents with community-based participatory action research to design and pilot strategies to enhance COVID-19 vaccine confidence in two underserved and ethnoculturally diverse neighbourhoods of Montreal, Canada. Two surveys conducted 6 months apart through primary and secondary schools are used to monitor vaccine acceptance and its social determinants among children and youth. Analyses of survey data include descriptive and inferential statistical approaches. Community-led design teams of parents and youth from the two participating neighbourhoods, supported by academic researchers, design thinking experts and community partners, use an HCD approach to: (1) gather data to understand COVID-19 vaccine decision-making among parents and youth in their community and frame a design challenge (inspiration phase); (2) develop an intervention to address the design challenge (ideation phase) and (3) pilot the intervention (implementation phase). Strategies to evaluate the community-led interventions will be co-developed during the implementation phase. ETHICS AND DISSEMINATION: This study has been approved by the research ethics boards of the Sainte-Justine University Hospital Centre and the University of Montreal. Community design teams will be involved in the dissemination of findings and the design of knowledge translation initiatives that foster dialogue related to COVID-19 vaccination for children and adolescents among community, school and public health stakeholders. Findings will be disseminated through peer-reviewed publications, conference presentations, community forums, policy briefs, and social media content.

Seroprevalence of SARS-CoV-2 Antibodies Among Children in School and Day Care in Montreal, Canada.

Importance: Quebec prioritized in-person learning after the first wave of the COVID-19 pandemic, with school closures being implemented temporarily in selected schools or in hot-spot areas. Quebec's decision to keep most schools open was controversial, especially in Montreal, which was the epicenter of Canada's first and second waves; therefore, understanding the extent to which children were infected with SARS-CoV-2 provides important information for decisions about school closures. Objective: To estimate the seroprevalence of SARS-CoV-2 antibodies in children and teenagers in 4 neighborhoods of Montreal, Canada. Design, Setting, and Participants: This cohort study (the Enfants et COVID-19: Étude de séroprévalence [EnCORE] study) enrolled a convenience sample of children aged 2 to 17 years between October 22, 2020, and March 22, 2021, in Montreal, Canada. Exposures: Potential exposure to SARS-CoV-2. Main Outcomes and Measures: The main outcome was seroprevalence of SARS-CoV-2 antibodies, collected using dried blood spots (DBSs) and analyzed with a research-based enzyme-linked immunosorbent assay (ELISA). Parents also completed an online questionnaire that included questions on self-reported COVID-19 symptoms and tests, along with sociodemographic questions. Results: This study included 1632 participants who provided a DBS sample from 30 day cares, 22 primary schools, and 11 secondary schools. The mean (SD) age of the children who provided a DBS sample was 9.0 (4.4) years; 801 (49%) were female individuals, with 354 participants (22%) from day cares, 725 (44%) from primary schools, and 553 (34%) from secondary schools. Most parents had at least a bachelor's degree (1228 [75%]), and 210 (13%) self-identified as being a racial or ethnic minority. The mean seroprevalence was 5.8% (95% CI, 4.6%-7.0%) but increased over time from 3.2% (95% CI, 0.7%-5.8%) in October to November 2020 to 8.4% (95% CI, 4.4%-12.4%) in March to April 2021. Of the 95 children with positive SARS-CoV-2 antibody results, 78 (82%) were not tested or tested negative with reverse transcription-polymerase chain reaction (RT-PCR) testing, and all experienced mild (49 [52%]) or no clinical symptoms (46 [48%]). The children of parents who self-identified as belonging to a racial and ethnic minority group were more likely to be seropositive compared with children of White parents (adjusted seroprevalence ratio, 1.9; 95% CI, 1.1-2.6). Conclusions and Relevance: These results provide a benchmark of the seroprevalence status in Canadian children. The findings suggest that there was more transmission occurring in children compared with what was being detected by RT-PCR, although children experienced few or mild symptoms. It will be important to continue monitoring the serological status of children, particularly in the context of new COVID-19 variants of concern and in the absence of mass vaccination campaigns targeting young children.

Social inequalities in COVID-19 vaccine acceptance and uptake for children and adolescents in Montreal, Canada

Background The success of current and prospective COVID-19 vaccine campaigns for children and adolescents will in part depend on the willingness of parents to accept vaccination. This study examined social determinants of parental COVID-19 vaccine acceptance and uptake for children and adolescents. Methods We used cross-sectional data from an ongoing COVID-19 cohort study in Montreal, Canada and included all parents of 2 to 18-year-olds who completed an online questionnaire between May 18 and June 26, 2021 (n = 809). We calculated child age-adjusted prevalence estimates of vaccine acceptance by parental education, race/ethnicity, birthplace, household income, and neighbourhood, and used multinomial logistic regression to estimate adjusted prevalence differences (aPD) and ratios (aPR). Social determinants of vaccine uptake were examined for the vaccine-eligible sample of 12 to 18 year-olds (n = 306). Results Intention to vaccinate children against COVID-19 was high, with only 12.4% of parents unlikely to have their child vaccinated. Parents with younger children were less likely to accept vaccination, as were those from lower-income households, racialized groups, and those born outside Canada. Children from households with annual incomes <$100,000 had 18.4 percent lower prevalence of being vaccinated/very likely vaccinated compared to household incomes ≥$150,000 (95% CI: 10.1 to 26.7). Racialized parents reported greater unwillingness to vaccinate vs. White parents (aPD = 10.3;95% CI: 1.5, 19.1). Vaccine-eligible adolescents from the most deprived neighbourhood were half as likely to be vaccinated compared to those from the least deprived neighbourhood (aPR = 0.48;95% CI: 0.18 to 0.77). Interpretation. This study identified marked social inequalities in COVID-19 vaccine acceptance and uptake for children and adolescents. Efforts are needed to reach disadvantaged and marginalized populations with tailored strategies that promote informed decision making and facilitate access to vaccination.

Seroprevalence of anti-SARS-CoV-2 antibodies among school and daycare children and personnel: protocol for a cohort study in Montreal, Canada.

INTRODUCTION: Further evidence is needed to understand the contribution of schools and daycares for the spread of COVID-19 in the context of diverse transmission dynamics and continually evolving public health interventions. The Enfants et COVID-19: Étude de séroprévalence (EnCORE) study will estimate the seroprevalence and seroconversion of SARS-CoV-2 among school and daycare children and personnel. In addition, the study will examine associations between seroprevalence and sociodemographic characteristics and reported COVID-19 symptoms and tests, and investigates changes in health, lifestyle and well-being outcomes. METHODS AND ANALYSIS: This study includes children and personnel from 62 schools and daycares in four neighbourhoods in Montreal, Canada. All children aged 2-17 years attending one of the participating schools or daycares and their parents are invited to participate, as well as a sample of personnel members. Participants respond to brief questionnaires and provide blood samples, collected via dried blood spot, at baseline (October 2020-March 2021) and follow-up (May-June 2021). Questionnaires include sociodemographic and household characteristics, reported COVID-19 symptoms and tests, potential COVID-19 risk factors and prevention efforts and health and lifestyle information. Logistic regression using generalised estimating equations will be used to estimate seroprevalence and seroconversion, accounting for school-level clustering. ETHICS AND DISSEMINATION: This study was approved by the research ethics boards of the Université de Montréal (CERSES) and the Centre Hospitalier Universitaire Sainte-Justine. Results will contribute to our knowledge about SARS-CoV-2 transmission in schools and daycares and will be made available to study participants and their families, school and public health decision-makers and the research community.