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.

Healthcare utilization among COVID-19 mRNA vaccine-associated myocarditis cases: a matched retrospective cohort study.

Objectives: We evaluated all-cause healthcare utilization among those with vaccine-associated myocarditis, compared to vaccinees without postvaccination myocarditis.

Methods: We conducted a retrospective cohort study in individuals aged 12 and older who received COVID-19 mRNA vaccination in British Columbia. Exposure was defined as an ED visit or hospitalization for myocarditis within 21 days postvaccination.

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.

A multiprovincial retrospective analysis of the incidence of myocarditis or pericarditis after mRNA vaccination compared to the incidence after SARS-CoV-2 infection.

Objective: To compare myocarditis/pericarditis risk after COVID-19 mRNA vaccination versus SARS-CoV-2 infection, and to assess if myocarditis/pericarditis risk varies by vaccine dosing interval.

Methods: In this retrospective cohort study, we used linked databases in Quebec, Ontario, and British Columbia between January 26, 2020, and September 9, 2021. We included individuals aged 12 or above who received an mRNA vaccine as the second dose or were SARS-CoV-2-positive by RT-PCR.

COVID-19 vaccines and adverse events of special interest: A multinational Global Vaccine Data Network (GVDN) cohort study of 99 million vaccinated individuals.

Background: The Global COVID Vaccine Safety (GCoVS) Project, established in 2021 under the multinational Global Vaccine Data Network™ (GVDN®), facilitates comprehensive assessment of vaccine safety. This study aimed to evaluate the risk of adverse events of special interest (AESI) following COVID-19 vaccination from 10 sites across eight countries.

Methods: Using a common protocol, this observational cohort study compared observed with expected rates of 13 selected AESI across neurological, haematological, and cardiac outcomes.

Prospective monitoring of adverse events following vaccination with Modified vaccinia Ankara - Bavarian Nordic (MVA-BN) administered to a Canadian population at risk of Mpox: A Canadian Immunization Research Network study.

MVA-BN is an orthopoxvirus vaccine that provides protection against both smallpox and mpox. In June 2022, Canada launched a publicly-funded vaccination campaign to offer MVA-BN to at-risk populations including men who have sex with men (MSM) and sex workers. The safety of MVA-BN has not been assessed in this context.

Background rates of adverse events of special interest for COVID-19 vaccines: A multinational Global Vaccine Data Network (GVDN) analysis.

Background: The Global COVID Vaccine Safety (GCoVS) project was established in 2021 under the multinational Global Vaccine Data Network (GVDN) consortium to facilitate the rapid assessment of the safety of newly introduced vaccines. This study analyzed data from GVDN member sites on the background incidence rates of conditions designated as adverse events of special interest (AESI) for COVID-19 vaccine safety monitoring.

Methods: Eleven GVDN global sites obtained data from national or regional healthcare databases using standardized methods.

A population-based assessment of myocarditis after messenger RNA COVID-19 booster vaccination among adult recipients.

Objectives: We aimed to estimate the rate of myocarditis after the messenger RNA (mRNA) COVID-19 booster vaccination by vaccine type, age, and sex.

Methods: We used data from the British Columbia COVID-19 Cohort, a population-based cohort surveillance platform. The exposure was a booster dose of an mRNA vaccine.

Uptake of Mpox vaccination among transgender people and gay, bisexual and other men who have sex with men among sexually-transmitted infection clinic clients in Vancouver, British Columbia.

Objectives: As the primary public health strategy for controlling the 2022 Mpox outbreak, it is critical to evaluate the impact of Mpox vaccination campaigns for transgender people and gay, bisexual and other men who have sex with men (T/GBM). We measured vaccine uptake and associated factors among T/GBM clients of an urban STI clinic in British Columbia (BC).

Methods: We conducted a cross-sectional online survey between August 8-22, 2022 of clients who had attended the STI clinic, 5-7 weeks following the first-dose Mpox vaccination campaign in BC.

Observed versus expected rates of myocarditis after SARS-CoV-2 vaccination: a population-based cohort study.

Background: Postmarketing evaluations have linked myocarditis to SARS-CoV-2 mRNA vaccines. We sought to estimate the incidence of myocarditis after mRNA vaccination against SARS-CoV-2, and to compare the incidence with expected rates based on historical background rates in British Columbia.

Methods: We conducted an observational study using population health administrative data from the BC COVID-19 Cohort from Dec.

Comparative Risk of Myocarditis/Pericarditis Following Second Doses of BNT162b2 and mRNA-1273 Coronavirus Vaccines.

Background: Postmarketing evaluations have linked myocarditis to COVID-19 mRNA vaccines. However, few population-based analyses have directly compared the safety of the 2 mRNA COVID-19 vaccines.

Objectives: This study aimed to compare the risk of myocarditis, pericarditis, and myopericarditis between BNT162b2 and mRNA-1273.

Two-Dose Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine Effectiveness With Mixed Schedules and Extended Dosing Intervals: Test-Negative Design Studies From British Columbia and Quebec, Canada.

Background: The Canadian coronavirus disease 2019 (COVID-19) immunization strategy deferred second doses and allowed mixed schedules. We compared 2-dose vaccine effectiveness (VE) by vaccine type (mRNA and/or ChAdOx1), interval between doses, and time since second dose in 2 of Canada's larger provinces.

Methods: Two-dose VE against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or hospitalization among adults ≥18 years, including due to Alpha, Gamma, and Delta variants of concern (VOCs), was assessed ≥14 days postvaccination by test-negative design studies separately conducted in British Columbia and Quebec, Canada, between 30 May and 27 November (epi-weeks 22-47) 2021.

Invasive group A streptococcal disease in pregnant women and young children: a systematic review and meta-analysis.

Background: The incidence of invasive disease caused by group A streptococcus (GAS) has increased in multiple countries in the past 15 years. However, despite these reports, to the best of our knowledge, no systematic reviews and combined estimates of the incidence of invasive GAS have been done in key high-risk groups. To address this, we estimated the incidence of invasive GAS disease, including death and disability outcomes, among two high-risk groups-namely, pregnant women and children younger than 5 years.

Clinical care pathway for the evaluation of patients with suspected VITT after ChAdOx1 nCoV-19 vaccination.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare complication after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) adenoviral vector vaccination. In British Columbia (BC), Canada, a provincial clinical care pathway was developed to guide clinicians in evaluating for VITT among patients who present with thrombocytopenia or thrombosis symptoms within 4 to 28 days after adenoviral vector vaccine exposure. All patients had enzyme-linked immunosorbent assay (ELISA) testing for platelet factor 4 (PF4) antibodies, and all cases with positive PF4-ELISA or d-dimer levels ≥2.

Comparative Single-Dose mRNA and ChAdOx1 Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2, Including Variants of Concern: Test-Negative Design, British Columbia, Canada.

Background: In British Columbia, Canada, most adults 50-69 years old became eligible for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in April 2021, with chimpanzee adenoviral vectored vaccine (ChAdOx1) restricted to ≥55-year-olds and second doses deferred ≥6 weeks to optimize single-dose coverage.

Methods: Among adults 50-69 years old, single-dose messenger RNA (mRNA) and ChAdOx1 vaccine effectiveness (VE) against SARS-CoV-2 infection and hospitalization, including variant-specific, was assessed by test-negative design between 4 April and 2 October 2021.

Results: Single-dose VE included 11 861 cases and 99 544 controls.

Population-based incidence of invasive pneumococcal disease in children and adults in Ontario and British Columbia, 2002-2018: A Canadian Immunization Research Network (CIRN) study.

Background: Invasive pneumococcal disease (IPD) burden, evaluated in Canada using reported confirmed cases in surveillance systems, is likely underestimated due to underreporting. We estimated the burden of IPD in Ontario and British Columbia (BC) by combining surveillance data with health administrative databases.

Methods: We established a cohort of 27,525 individuals in Ontario and BC.

Priorities for sexually transmitted infection vaccine research and development: Results from a survey of global leaders and representatives.

Objective: To determine the sexually transmitted infection (STI) vaccine research priorities of global leaders in STI vaccine research, development, and service provision.

Methods: Global representatives attending the symposium preceding the STI & HIV World Congress in 2019 were invited to complete an electronic survey. We asked participants to rank items by importance/priority for STI vaccine development for the following areas of focus: specific STIs (gonorrhea, chlamydia, syphilis, herpes, and trichomoniasis), broad research domains (basic science, funding, communication, program planning, and vaccine hesitancy), and specific research activities related to these domains.

Myocarditis and Pericarditis After COVID-19 mRNA Vaccination: Practical Considerations for Care Providers.

The mRNA vaccines against COVID-19 infection have been effective in reducing the number of symptomatic cases worldwide. With widespread uptake, case series of vaccine-related myocarditis/pericarditis have been reported, particularly in adolescents and young adults. Men tend to be affected with greater frequency, and symptom onset is usually within 1 week after vaccination.

High-risk HPV prevalence among women undergoing cervical cancer screening: Findings a decade after HPV vaccine implementation in British Columbia, Canada.

Background: British Columbia (BC) introduced a publicly funded, school-based human papillomavirus (HPV) immunization program in 2008 with the quadrivalent vaccine. In 2010/2011, a baseline evaluation of HPV prevalence was conducted among women undergoing cervical cancer screening. After 10 years of publicly funded HPV vaccination, HPV-type prevalence was re-evaluated.

Single-dose mRNA Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), Including Alpha and Gamma Variants: A Test-negative Design in Adults 70 Years and Older in British Columbia, Canada.

Background: Randomized-controlled trials of messenger RNA (mRNA) vaccine protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) included relatively few elderly participants. We assess single-dose mRNA vaccine effectiveness (VE) in adults ≥ 70 years old in British Columbia, Canada, where second doses were deferred by up to 16 weeks and where a spring 2021 wave uniquely included codominant circulation of Alpha (B.1.

Exploring vaccination practices of midwives in British Columbia.

Background: Registered midwives in British Columbia (BC) are primary health care practitioners for healthy people throughout pregnancy and for approximately 6 weeks postpartum. BC registered midwives are authorized to prescribe and administer certain vaccines to adults under their care during the perinatal period and hepatitis B vaccine to high-risk newborns. However, little has been documented about their recommendations for, and administration of, prenatal and infant vaccinations.

Declining rates of cervical intraepithelial neoplasia in British Columbia, Canada: An ecological analysis on the effects of the school-based human papillomavirus vaccination program.

Since 2008, girls in British Columbia (BC), Canada, have been offered HPV vaccination through a school-based, publicly funded immunization program. The oldest birth cohort eligible for the vaccination program was born in 1994 and uptake is on average 63%. To evaluate the impact of the HPV vaccine in BC, ecological trends in cervical intraepithelial neoplasia (CIN) rates were assessed in young women before and after the implementation of the HPV vaccination program.

Association between human papillomavirus vaccine status and sexually transmitted infection outcomes among females aged 18-35 with a history of sexual activity in the United States: A population survey-based cross-sectional analysis.

Background: Current human papillomavirus (HPV) vaccine coverage in the United States (in 2019, 66-70%), remains below the Healthy People 2020 coverage goal of 80%. HPV vaccine misinformation, including parental concerns of sexual risk-compensation influence vaccine uptake. We examined the association between HPV vaccination and sexually transmitted infection (STI) outcomes.

Impacts of Human Papillomavirus Immunization Programs on Rates of Anogenital Warts in British Columbia, Canada, 2000 to 2017.

Background: In 2008, British Columbia (BC) implemented a school-based quadrivalent human papillomavirus (HPV-4) immunization program for girls born in 1994 or later. In 2015, an expanded clinic-based program included men who report sex with men (MSM) born in 1989 or later. To evaluate the impacts of HPV-4 programs on anogenital warts (AGWs), diagnosis rates were measured among women who report sex with men (WSM), men who report sex with women (MSW), and MSM.