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.

Report of a SPEAC webinar 22 september 2023: Sensorineural hearing loss, lassa virus disease and vaccines.

Lassa virus (LASV) belongs to the Arenavirus family. LASV is endemic in several West Africa countries and causes viral hemorrhagic fevers. The Nigeria CDC has reported that an outbreak in 2024 in 28 states has resulted in 7767 suspected cases of Lassa fever, 971 confirmed cases and 166 confirmed deaths up to 11 August.

Participant-reported neurological events following immunization in the Canadian National Vaccine Safety Network-COVID-19 vaccine (CANVAS-COVID) study.

Introduction: The Canadian National Vaccine Safety Network (CANVAS) conducted active participant-based surveillance for adverse events following immunization during the COVID-19 vaccine campaign. This study evaluated the association between COVID-19 vaccination and neurological adverse events.

Methods: Participants were invited to complete online surveys to report health events that prevented daily activities and/or required medical attention within 7 days after COVID-19 vaccination or 7 days prior to the survey (unvaccinated controls); follow-up surveys were sent 7 months later.

Impact of recruitment strategies on individual participation practices in the Canadian National Vaccine Safety Network: prospective cohort study.

Background: The Canadian National Vaccine Safety (CANVAS) network conducted a multi-center, prospective vaccine safety study to collect safety data after dose 1 and 2 of COVID-19 vaccines and follow up safety information 7 months after dose 1.

Objective: This study aimed to describe and evaluate the recruitment methods used by CANVAS and the retention of participants by each modality.

Methods: CANVAS deployed a multi-pronged recruitment approach to reach a larger sample, without in-person recruitment.

Revaccination outcomes among adolescents and adults with suspected hypersensitivity reactions following COVID-19 vaccination: A Canadian immunization research network study.

Background: COVID-19 vaccination has been associated with anaphylaxis and hypersensitivity reactions. Infectious disease physicians and allergists in the Canadian Special Immunization Clinic (SIC) Network developed guidance for evaluating patients with adverse events following immunization (AEFI) including suspected hypersensitivity. This study evaluated management and adverse event recurrence following subsequent COVID-19 vaccinations.

A scoping review of active, participant centred, digital adverse events following immunization (AEFI) surveillance of WHO approved COVID-19 vaccines: A Canadian immunization Research Network study.

This scoping review examines the role of digital solutions in active, participant-centered surveillance of adverse events following initial release of COVID-19 vaccines. The goals of this paper were to examine the existing literature surrounding digital solutions and technology used for active, participant centered, AEFI surveillance of novel COVID-19 vaccines approved by WHO. This paper also aimed to identify gaps in literature surrounding digital, active, participant centered AEFI surveillance systems and to identify and describe the core components of active, participant centered, digital surveillance systems being used for post-market AEFI surveillance of WHO approved COVID-19 vaccines, with a focus on the digital solutions and technology being used, the type of AEFI detected, and the populations under surveillance.

Resource use and disease severity of children hospitalized for COVID-19 versus multisystem inflammatory syndrome in children (MIS-C) in Canada.

Background: Direct comparisons of paediatric hospitalizations for acute coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C) can inform health system planning. We describe the absolute and relative hospital burden of acute paediatric COVID-19 and MIS-C in Canada.

Methods: This national prospective study was conducted via the Canadian Paediatric Surveillance Program from March 2020-May 2021.

The safety of seasonal influenza vaccination among adults prescribed immune checkpoint inhibitors: A self-controlled case series study using administrative data.

Background: Immune checkpoint inhibitor (ICI) therapy for patients undergoing cancer treatment carries a risk of severe immune-related adverse events (IRAEs). Questions remain about whether seasonal influenza vaccination might increase the risk of developing IRAEs among these patients given that vaccines are immunomodulatory. Previous vaccine safety studies on patients with cancer prescribed ICI therapy have demonstrated conflicting results.

The current state of pertussis vaccination in pregnancy around the world, with recommendations for improved care: Consensus statements from the Global Pertussis Initiative.

Bordetella pertussis, which causes a respiratory disease known as pertussis ("whooping cough") remains an important global challenge, with the incidence in pertussis cases increasing in recent years. Newborns and infants are at increased risk for severe morbidity and mortality from this bacterium. Vaccination in pregnancy has become an important strategy to both passively transfer immunity as well as prevent infection in pregnant persons, who are a major source of newborn infection, thus attempting to decrease the impact of this serious disease.

Parent and healthcare provider views of live varicella vaccination of pediatric solid organ transplant recipients.

Background: Live attenuated varicella vaccine (LAVV) has historically been contraindicated in children who are immunocompromised due to solid organ transplant (SOT) because of safety concerns. Recently, clinical guidelines were developed that support post-transplant varicella vaccination in selected SOT recipients based on emerging evidence of LAVV safety. This qualitative study sought to explore barriers and facilitators to implementing the new guidelines, as well as acceptability of LAVV among healthcare providers (HCPs) and parents.

Factors associated with intention for revaccination among patients with adverse events following immunization.

Objectives: Individuals and healthcare providers may be uncertain about the safety of revaccination after an adverse event following immunization (AEFI). We identified factors associated with physician recommendation for revaccination and participant intention to be revaccinated among patients with adverse events following immunization (AEFIs) assessed in the Canadian Special Immunization Clinic (SIC) Network from 2013 to 2019.

Methods: This prospective observational study included patients assessed in the Canadian Special Immunization Clinic Network from 2013 to 2019 for an AEFI who required additional doses of the vaccine temporally associated with their AEFI.

Safety and immunogenicity of the live-attenuated varicella vaccine in pediatric solid organ transplant recipients: A systematic review and meta-analysis.

This study aimed to synthesize the available evidence on the immunogenicity, safety, and effectiveness of live-attenuated varicella vaccine in solid organ transplant recipients. Medline and EMBASE were searched using predefined search terms to identify relevant studies. The included articles reported varicella vaccine administration in the posttransplant period in children and adults.

COVID-19 vaccination in pregnancy: How discrepant public health discourses shape responsibility for fetal health.

Early in COVID-19 vaccine rollout, expert recommendations about vaccination while pregnant and breastfeeding changed rapidly. This paper addresses the (re)production of gendered power relations in these expert discourses and recommendations in Canada. We collected texts about COVID-19 vaccine use in pregnancy (N ​= ​52) that Canadian health organizations (e.

A narrative review of vaccine pharmacovigilance during mass vaccination campaigns: Focus on myocarditis and pericarditis after COVID-19 mRNA vaccination.

Vaccines have had a tremendous impact on reducing the burden of infectious diseases; however, they have the potential to cause adverse events following immunization (AEFIs). Prelicensure clinical trials are limited in their ability to detect rare AEFIs that may occur in less than one per thousand individuals. While postmarketing surveillance systems have shown COVID-19 mRNA vaccines to be safe, they led to the identification of rare cases of myocarditis and pericarditis after COVID-19 vaccination that were not initially detected in clinical trials.

Anaphylaxis: Revision of the Brighton collaboration case definition.

The Brighton Collaboration (BC) has formulated a number of case definitions which have primarily been applied to adverse events of special interest in the context of vaccine safety surveillance. This is a revision of the 2007 BC case definition for anaphylaxis. Recently, the BC definition has been widely used for evaluating reports of suspected anaphylaxis following COVID-19 vaccination.

Adverse Events Following Immunization With mRNA and Viral Vector Vaccines in Individuals With Previous Severe Acute Respiratory Syndrome Coronavirus 2 Infection From the Canadian National Vaccine Safety Network.

Background: Adults previously infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) develop short-term immunity and may have increased reactogenicity to coronavirus disease 2019 (COVID-19) vaccines. This prospective, multicenter, active-surveillance cohort study examined the short-term safety of COVID-19 vaccines in adults with a prior history of SARS-CoV-2.

Methods: Canadian adults vaccinated between 22 December 2020 and 27 November 2021 were sent an electronic questionnaire 7 days post-dose 1, dose 2, and dose 3 vaccination.

Risk factors for severe PCR-positive SARS-CoV-2 infection in hospitalised children.

Objective: To identify risk factors for severe disease in children hospitalised for SARS-CoV-2 infection.

Design: Multicentre retrospective cohort study.

Setting: 18 hospitals in Canada, Iran and Costa Rica from 1 February 2020 to 31 May 2021.

SARS-CoV-2 infection in technology-dependent children: a multicenter case series.

Purpose: The objective of this study was to describe the clinical course and outcomes in children with technology dependence (TD) hospitalized with SARS-CoV-2 infection.

Methods: Seventeen pediatric hospitals (15 Canadian and one each in Iran and Costa Rica) included children up to 17 years of age admitted February 1, 2020, through May 31, 2021, with detection of SARS-CoV-2. For those with TD, data were collected on demographics, clinical course and outcome.

Safety of COVID-19 vaccines in pregnancy: a Canadian National Vaccine Safety (CANVAS) network cohort study.

Background: Pregnant individuals have been receiving COVID-19 vaccines following pre-authorisation clinical trials in non-pregnant people. This study aimed to determine the frequency and nature of significant health events among pregnant females after COVID-19 vaccination, compared with unvaccinated pregnant controls and vaccinated non-pregnant individuals.

Methods: We did an observational cohort study, set in seven Canadian provinces and territories including Ontario, Quebec, British Columbia, Alberta, Nova Scotia, Yukon, and Prince Edward Island.