Safety and Immunogenicity of a Pneumococcal Conjugate Vaccine When Administered Concomitantly With Routine Pediatric Vaccines in Healthy Toddlers and Infants.

Background: A 21-valent pneumococcal conjugate vaccine, PCV21, was developed to provide broader coverage against Streptococcus pneumoniae serotypes. PCV21 comprises 13 serotypes common to a licensed 13-valent pneumococcal conjugate vaccine (PCV13) and 8 additional serotypes. This study evaluated 3 PCV21 formulations with differences in antigen content for some serotypes, compared with PCV13, administered concomitantly with routine pediatric vaccines.

Knowledge gaps and research priorities regarding vaccination in pregnancy: A Canadian perspective from the prevention of infections in the maternal-infant dyad (PRIMED) consortium.

Vaccination in pregnancy is a safe and effective method for protecting both the pregnant woman/person and their infant from communicable diseases. Despite a growing body of evidence of the benefits of vaccination during pregnancy and the widespread introduction of vaccines during pregnancy for influenza, pertussis, and COVID-19, there is no national research agenda in Canada to guide funding and research. We sought to create a roadmap for Canadian vaccination in pregnancy research.

Group B disease during infancy and risk of subsequent neurodevelopmental impairments in young children: a population-based cohort study in Ontario, Canada.

Background: Group B (GBS) is a leading infectious cause of neonatal morbidity and mortality worldwide, yet data on longer-term outcomes in children remain limited. We aimed to assess the risk of neurodevelopmental impairments (NDIs) in GBS survivors and to explore effect modification by sex and prematurity.

Methods: We performed a population-based cohort study of liveborn infants in Ontario between April 2012 and March 2018, using linked birth registry, laboratory, and health administrative databases.

RSV Hospital Admissions During the First 2 Seasons Among Children With Chronic Medical Conditions.

Importance: National Immunization Technical Advisory Groups recommend long-acting monoclonal antibody prophylaxis for the prevention of respiratory syncytial virus (RSV) disease for children at high risk in the first season, regardless of RSV vaccination during pregnancy, and for those who remain at increased risk in the second season.

Objective: This study assessed which groups of children with chronic medical conditions (CMCs) are at higher risk of RSV hospitalization during their first and second RSV seasons.

Design, Setting, And Participants: This retrospective, population-based, season-stratified cohort analysis was conducted among children who were born between April 1, 2013, and March 31, 2023, in British Columbia, Canada (population of 5.

-associated hemolytic uremic syndrome Canadian Immunization Monitoring Program ACTive National Pediatric Surveillance (1991 to 2019).

Objectives: -associated hemolytic uremic syndrome (SP-HUS) is an underreported cause of pediatric atypical HUS. This study describes the epidemiology of the largest Canadian case series of SP-HUS in comparison with non-HUS invasive pneumococcal disease (IPD).

Methods: The Canadian Immunization Monitoring Program, ACTive (IMPACT) is a national surveillance network for vaccine-preventable diseases.

Severity of COVID-19 in Hospitalized Immunocompromised Children Across Canada.

Background: The association of immunocompromised states with pediatric COVID-19 outcomes remains unclear. This study assessed COVID-19 severity in hospitalized children with and without immunocompromising conditions.

Methods: Children <17 years hospitalized in Canada for COVID-19 (April 2020-December 2022) were identified through the Canadian Paediatric Surveillance Program and Canadian Immunization Monitoring Program, ACTive.

Neurological adverse events following COVID-19 vaccination among Canadians referred to the special immunization clinic network.

Neurological adverse events have been reported rarely following COVID-19 vaccination. This study describes the characteristics of adolescents and adults assessed in the Canadian Special Immunization Clinic (SIC) Network for neurological adverse events following immunization (AEFIs) and outcomes of revaccination. Among 60 participants enrolled from January 2021 to February 2023, paresthesia/anesthesia was the most common diagnosis (15/60; 25.

Active Surveillance for Myocarditis and Pericarditis in Canadian Children from 2021 to 2022: A Canadian Immunization Monitoring Program ACTive Study.

Objective: To compare characteristics of children assessed at Canadian Immunization Monitoring Program Active (IMPACT) centers for myocarditis, myopericarditis, and pericarditis according to COVID-19 vaccination status, and to evaluate the association with vaccination.

Study Design: IMPACT conducted active surveillance for myocarditis, myopericarditis, and pericarditis by monitoring admission lists and diagnostic codes for children ≤16 years of age assessed in emergency departments or hospitalized with these conditions (June 2021 through December 2022). Clinical details and immunization histories were entered in an electronic database.

Antimicrobial resistance and vaccines in Enterobacteriaceae including extraintestinal pathogenic Escherichia coli and Klebsiella pneumoniae.

Antimicrobial-resistant Enterobacteriaceae are increasingly a clinical challenge. In particular, extraintestinal pathogenic Escherichia coli and Klebsiella pneumoniae threaten public health. Vaccination presents a long-term strategy to reduce both drug-susceptible and resistant infections while maintaining current clinical therapies.

Influenza-Associated Mortality Among Children in Canada from 2004 to 2022.

We identified 80 pediatric influenza-associated deaths in Canadian pediatric tertiary hospitals from 2004 to 2022. Children aged <5 years and with high-risk conditions represented 55% and 77.5% of cases, respectively.

Risk Factors for Severe Disease Among Children Hospitalized With Respiratory Syncytial Virus.

Importance: A resurgence of respiratory syncytial virus (RSV)-associated acute respiratory tract infection (ARI) was observed in 2022 and 2023 after the COVID-19 pandemic. Changes in the demographic characteristics, disease severity, and outcomes of patients were observed, which could impact the identification of risk groups for interventions aimed at reducing the severity of RSV disease.

Objectives: To identify factors associated with severe clinical outcomes among children hospitalized with RSV-associated ARIs in 2022 and 2023.

Hospital admissions for acute respiratory tract infections among infants from Nunavut and the burden of respiratory syncytial virus: a 10-year retrospective cohort study.

Background: Nunavut is a northern Canadian territory where a high proportion of infants are admitted to hospital with acute respiratory tract infection (ARI). Previous studies have been limited in regional and/or short duration of coverage. This study aimed to estimate the incidence rate, microbiology and outcomes of ARI hospitalizations in Nunavut infants.

Characterization of Canadian Neisseria meningitidis serogroup B isolates and factor-H binding protein expression, data from the Canadian Immunization Monitoring Program Active (IMPACT), 2013-2020.

Background: Invasive meningococcal disease, caused by Neisseria meningitidis, remains a significant health threat. This study examined the genetic diversity of serogroup B (NmB) organisms and assessed the potential coverage offered by the MenB-FHbp vaccine, licensed for individuals aged 10-25 years. NmB vaccines have not yet been incorporated into most routine immunization programs in Canada, with the exception of campaigns to deal with specific outbreaks and targeted vaccination efforts for at-risk groups.

Future immunisation strategies to prevent Streptococcus pneumoniae infections in children and adults.

Streptococcus pneumoniae is a major respiratory pathogen, causing 1·2 million deaths and 197 million pneumonia episodes globally in 2016. The spread of S pneumoniae to sterile sites, such as the blood and brain, leads to invasive pneumococcal disease. The best approach available for prevention of invasive pneumococcal disease in children and, more recently, adults is the use of pneumococcal conjugate vaccines (PCVs).

Performance of the World Health Organization (WHO) severe acute respiratory infection (SARI) case definitions in hospitalized children and youth: cross-sectional study.

Background: Respiratory tract infections with viral pathogens are frequently identified using the World Health Organization (WHO) case definition of severe acute respiratory infection (SARI), defined as fever of ≥38°Celsius, cough, onset within 10 days, and hospitalization. While there is extensive research in adults, less is known about the WHO SARI case definition performance in children and youth. We aimed to determine the performance of the WHO SARI and modified case definitions in identifying viral respiratory tract infections in hospitalized children and youth.

Epidemiology of Febrile Seizures During the Covid-19 Pandemic: A Canadian Immunization Monitoring Program-Active (IMPACT) Study.

Active surveillance for febrile seizures was conducted at 12 Canadian pediatric centers (August 2021-December 2022). Of 3367 cases, 649 (19%) were hospitalized, 156/3367 (5%) had laboratory-confirmed acute SARS-CoV-2 infection, 363 (11%) had non-SARS-CoV-2 infection and 107 (3%) occurred as adverse events following immunization (vaccinated within 15 days before presentation). Febrile seizures were more frequently associated with infection than vaccination.

Term immune memory responses to human papillomavirus (HPV) vaccination following 2 versus 3 doses of HPV vaccine.

Human papillomavirus (HPV) vaccines provide excellent protection from infection and disease. The minimum number of doses needed for long-term protection and the potential need for boosters are areas of continuing interest. Studies on the durability of vaccines have focused on antibodies, fewer have analyzed memory immune cells that could provide protection even when antibody levels are low.

Humoral and cell-mediated immune responses to COVID-19 vaccines up to 6 months post three-dose primary series in adults with inborn errors of immunity and their breakthrough infections.

Purpose: Many individuals with inborn errors of immunity (IEIs) have poor humoral immune (HI) vaccine responses. Only a few studies have examined specific cell-mediated immune (CMI) responses to coronavirus disease 2019 (COVID-19) vaccines in this population. Therefore, the purpose of this study was to examine HI and CMI responses up to 6 months post-COVID-19 vaccine dose 3 in adults with IEIs.

Acceptance and attitudes towards COVID-19 vaccination during pregnancy in Canada.

The COVID-19 pandemic posed a unique set of risks to pregnant women and pregnant people. SARS-CoV-2 infection in pregnancy is associated with increased risk of severe illness and adverse perinatal outcomes. However, evidence regarding the use of COVID-19 vaccines in pregnancy shows safety and efficacy.

Child Transmission of SARS-CoV-2 Throughout the Pandemic: An Updated Systematic Review and Meta-analysis.

Background: This systematic review sought to characterize child-to-child and child-to-adult transmission of severe acute respiratory coronavirus 2 (SARS-CoV-2).

Methods: A systematic review was conducted from April 1, 2021, to December 15, 2023, to estimate secondary attack rates (SARs) and secondary infections per index case (case rate) from index cases up to age 20 years. SAR and case rate were analyzed based on age, setting, country and variant prevalence.

Pediatric COVID-19 severity by SARS-CoV-2 lineage and vaccine status in Canada: an IMPACT study.

Background: Interpretations of pediatric COVID-19 severity are complicated by novel lineages and COVID-19 vaccine introduction. We estimated the risk of severe COVID-19 by SARS-CoV-2 lineage and vaccination status among hospitalized Canadian children.

Methods: Data were collected through the Canadian Paediatric Surveillance Program (April 2020-May 2021) and Canadian Immunization Monitoring Program, ACTive (June 2021-December 2022).

mRNA COVID-19 vaccine safety among children and adolescents: a Canadian National Vaccine Safety Network cohort study.

Background: The Canadian National Vaccine Safety Network conducted active safety surveillance for COVID-19 vaccines. This study aimed to characterize the short-to-medium term safety of mRNA COVID-19 vaccines across the pediatric age spectrum.

Methods: In this cohort study, vaccinated and unvaccinated children and adolescents aged 6 months to 19 years from eight Canadian provinces and territories were invited to participate.