Viral Loads of Pneumoviruses: Correlation With Coinfection Rates and Disease Severity.

We looked at the interactions between viral loads, coinfection rates and disease severity for children infected with two pneumoviruses: human metapneumovirus (HMPV) and respiratory syncytial virus (RSV). The HMPV RNA load in nasopharyngeal swabs of hospitalized children was significantly higher in mono-infections compared to coinfections but this was not the case for RSV, which could be explained by different innate immune responses. Also, the viral load of neither of the two viruses was associated with disease severity although RSV-infected children had higher severity scores than HMPV-infected children.

Parental decisions regarding the vaccination of children and adolescents against SARS-CoV-2 from 2020 to 2023: A descriptive longitudinal study of parents and children in Montreal, Canada.

Background: Given the growing evidence on the benefits of hybrid immunity, continued monitoring of vaccine uptake is warranted, particularly of socio-demographic subgroups with early vaccine hesitancy. Racial/ethnic and lower income groups experienced a high infection incidence, but few studies account for the child's history of SARS-CoV-2 infection on the parent's decision to vaccinate their child.

Methods: EnCORE is a SARS-CoV-2 pediatric cohort study comprising five rounds of data collection from 2020 to 2023, with parental questionnaires at each round.

Omicron incidence and seroprevalence among children in Montreal, Canada, in early 2023: final results from the longitudinal EnCORE serology study.

Since early 2022, routine testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) based on symptoms and exposure history has largely ceased in Canada. Consequently, seroprevalence studies, particularly longitudinal studies, have become critical for monitoring the rate of incident SARS-CoV-2 infections and the proportion of the population with evidence of immunity. EnCORE is a longitudinal SARS-CoV-2 seroprevalence study comprising five rounds of serology testing from October 2020 to June 2023, in a sample of 2- to 17-year-olds (at baseline), recruited from daycares and schools in four neighbourhoods of Montreal, Canada.

SARS-CoV-2 seroprevalence and mental health of school staff: a cross-sectional study of schools from four areas of Montreal, Quebec in 2021.

Objectives: To assess the seroprevalence of infection-acquired SARS-CoV-2 and the mental health of school/daycare staff in the months after reopening of schools in Montreal, Quebec (Canada) in the Fall of 2020 and whether these varied by school and participant characteristics.

Design: A cross-sectional design based on a convenience sample of schools/daycares and staff was used as the originally planned longitudinal design was no longer feasible due to obstacles in recruitment, for example, teacher's strike.

Setting: Forty-nine schools/daycares in four Montreal neighbourhoods from March to October 2021.