Active surveillance of acute paediatric hospitalisations demonstrates the impact of vaccination programmes and informs vaccine policy in Canada and Australia

Burden of paediatric hospitalisations to the health care system, child and family: a systematic review of Australian studies (1990-2022)

Background

Paediatric hospitalisations represent a significant cost to the health system and cause significant burden to children and their families. Understanding trends in hospitalisation costs can assist with health planning and support strategies across stakeholders. The objective of this systematic review is to examine the trends in costs and burden of paediatric hospitalisations in Australia to help inform policy and promote the well-being of children and their families.

Methods

Electronic data sources (Embase, Medline, Web of Science, PSYCH-Info, CINAHL and Scopus) were searched from 1990 until December 2022. Any quantitative or qualitative studies conducted in Australian tertiary hospitals were included in the review. Eligible studies were those that included paediatric (<18 years) hospitalisations and reported on economic and/or non-economic costs for the child, family unit and/or health system. Study quality and risk of bias for each study were assessed with the Joanna Briggs Critical Appraisal Tools. We present a summary of the findings of the hospitalisation burden across major diagnostic admission categories and for the child and family unit. The systematic review was registered with Prospero (ID: CRD42021276202).

Findings

The review summarises a total of 88 studies published between 1990 and December 2022. Overall, the studies identified that paediatric hospitalisations incur significant financial costs, which have not shown significant reductions over time. In-patient direct hospital costs varied depending on the type of treatment and diagnostic condition. The costs per-case were found to range from just below AUD$2000 to AUD$20,000 or more. The financial burden on the family unit included loss of productivity, transport and travel costs. Some studies reported estimates of these costs upward of AUD$500 per day. Studies evaluating 'hospital in the home' options identified significant benefits in reducing hospitalisations and costs without compromising care.

Interpretation

Increasing focus on alternative models of care may help alleviate the significant costs associated with paediatric hospitalisation.

Funding

This research was supported by Hospitals United for Sick Kids (formerly Curing Homesickness).

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. In this narrative review, we highlight concepts of vaccine pharmacovigilance during mass vaccination campaigns and compare the approaches used in the context of myocarditis and pericarditis following COVID-19 vaccination to historical examples. We describe mechanisms of passive and active surveillance, their strengths and limitations, and how they interacted to identify and characterize the safety signal of myocarditis and pericarditis after COVID-19 mRNA vaccination. Articles were synthesized from a PubMed search using relevant keywords for articles published on vaccine surveillance systems and myocarditis and pericarditis after COVID-19 vaccination, as well as the authors' collections of relevant publications and grey literature reports. The global experience around the identification and monitoring of myocarditis and pericarditis after COVID-19 mRNA vaccination has provided important lessons for vaccine safety surveillance and highlighted its importance in maintaining public trust in mass vaccination programmes in a pandemic context.

Safety of COVID-19 Pfizer-BioNtech (BNT162b2) mRNA vaccination in adolescents aged 12-17 years: A systematic review and meta-analysis

The COVID-19 pandemic has severely affected adolescents. Safe and effective vaccines are pivotal tools in controlling this pandemic. We reviewed the safety profile of the BNT162b2 COVID-19 vaccine in adolescents using mostly real-world data to assist decision-making. We used random-effects model meta-analysis to derive pooled rates of single or grouped adverse events following immunization (AEFI) after each primary and booster dose, as well as after combining all doses. Reporting on over one million participants with safety data were included. The most-reported local and systemic AEFIs were pain/swelling/erythema/redness and fatigue/headache/myalgia, respectively. AESIs were rarely reported but were more frequent after the second dose than they were after the first and the booster doses. Health impact was less common among adolescents after receiving BNT162b2 vaccine. Rare life-threatening AEFIs were reported across all doses in real-world studies. Our findings highlight the significance of enhancing national and regional vaccination programs to ensure public confidence.

Kawasaki disease following immunization reported to the Canadian Immunization Monitoring Program ACTive (IMPACT) from 2013 to 2018

Kawasaki disease (KD) is an acute systemic vasculitis primarily affecting children younger than 5 y of age that has been reported as an adverse event following immunization (AEFI). The Canadian Immunization Monitoring Program ACTive (IMPACT) conducts active surveillance for KD following immunization across Canada. We characterized KD cases reported to IMPACT between 2013 and 2018. Cases admitted to an IMPACT hospital with a physician diagnosis of complete or incomplete KD with onset 0–42 d following vaccination were reviewed. Cases meeting the Brighton Collaboration case definition (BCCD) levels of diagnostic certainty levels 1 a/b, 2a/b or 3a-e were defined as KD cases. Demographic and vaccination characteristics were compared between KD cases and non-cases. Of 84 cases reviewed, 58 met the BCCD: 47 (81%) cases met level 1a (Complete KD), 8 (14%) met level 1b (Incomplete KD), 2 (3%) met level 2a, and 1 (2%) met level 2c (Probable KD). Median age at admission was 13 months (interquartile range 7–26 months). A median of 9.5 cases were reported per year (range 4–14). Thirty-one (53%) KD cases were temporally associated with diphtheria-tetanus acellular pertussis containing vaccinations, followed by 21 (36%) cases with pneumococcal conjugate vaccines. Symptom onset was 0–14 d after vaccination in 32 (55%) cases. Echocardiogram results were available for 43 (74%) cases with 22 reported as abnormal. Age, sex, interval to symptom onset, and vaccines received were similar between KD cases and non-cases. No safety signals were detected in these data.

The effect of the COVID-19 pandemic on influenza-related hospitalization, intensive care admission and mortality in children in Canada: A population-based study

Background

The COVID-19 pandemic resulted in unprecedented implementation of wide-ranging public health measures globally. During the pandemic, dramatic decreases in seasonal influenza virus detection have been reported worldwide. Information on the impact on paediatric influenza-related hospitalisations is limited. We describe influenza-related hospitalisation in children in Canada following the onset of the COVID-19 pandemic.

Methods

Data on influenza-related hospitalisations, intensive care unit (ICU) admissions and in-hospital deaths in children across Canada were obtained from the Canadian Immunisation Monitoring Program, ACTive (IMPACT). This national active surveillance initiative comprises 90% of all tertiary care paediatric beds in Canada. The study period included eleven influenza seasons, from the 2010/2011 season until the 2020/2021 season inclusive. Time series modelling was used to compare the observed to predicted influenza-related hospitalisations following the COVID-19 pandemic.

Results

Following the COVID-19 pandemic there was a significant decrease in paediatric influenza-related hospitalisations compared to predicted influenza-related hospitalisations for this time period (p < 0•0001). No paediatric influenza-related hospitalisations, ICU admission or deaths were reported for the 2020/2021 influenza season.

Conclusions

We show complete absence of paediatric influenza infection-related hospitalisation in a Canadian National Surveillance Network during the 2020/2021 influenza season. This significant decrease is likely related in large part to non-pharmacological public health interventions implemented during the COVID-19 pandemic, although the potential role of viral interference is unknown.

Funding

The Canadian Immunisation Monitoring Program, Active (IMPACT) influenza surveillance is a national surveillance initiative managed by the Canadian Paediatric Society and conducted by the IMPACT network of paediatric investigators on behalf of the Public Health Agency of Canada's Centre for Immunisation and Respiratory Infectious Diseases.

Prospective characterisation of SARS-CoV-2 infections among children presenting to tertiary paediatric hospitals across Australia in 2020: a national cohort study

OBJECTIVE

To present Australia-wide data on paediatric COVID-19 and multisystem inflammatory syndromes to inform health service provision and vaccination prioritisation.

DESIGN

Prospective, multicentre cohort study.

SETTING

Eight tertiary paediatric hospitals across six Australian states and territories in an established research surveillance network-Paediatric Active Enhanced Disease (PAEDS).

PARTICIPANTS

All children aged <19 years with SARS-CoV-2 infection including COVID-19, Paediatric Inflammatory Multisystem Syndrome Temporally Associated with SARS-CoV-2 (PIMS-TS) and Kawasaki-like disease TS infection (KD-TS) treated at a PAEDS site from 24 March 2020 to 31 December 2020.

INTERVENTION

Laboratory-confirmed SARS-CoV-2 infection.

MAIN OUTCOME

Incidence of severe disease among children with COVID-19, PIMS-TS and KD-TS. We also compared KD epidemiology before and during the COVID-19 pandemic.

RESULTS

Among 386 children with SARS-CoV-2 infection, 381 (98.7%) had COVID-19 (median 6.3 years (IQR 2.1-12.8),53.3% male) and 5 (1.3%) had multisystem inflammatory syndromes (PIMS-TS, n=4; KD-TS, n=1) (median 7.9 years (IQR 7.8-9.8)). Most children with COVID-19 (n=278; 73%) were Australian-born from jurisdictions with highest community transmission. Comorbidities were present in 72 (18.9%); cardiac and respiratory comorbidities were most common (n=32/72;44%). 37 (9.7%) children with COVID-19 were hospitalised, and two (0.5%) required intensive care. Postinfective inflammatory syndromes (PIMS-TS/KD-TS) were uncommon (n=5; 1.3%), all were hospitalised and three (3/5; 60%) required intensive care management. All children recovered and there were no deaths. KD incidence remained stable during the pandemic compared with prepandemic.

CONCLUSIONS

Most children with COVID-19 had mild disease. Severe disease was less frequent than reported in high prevalence settings. Preventative strategies, such as vaccination, including children and adolescents, could reduce both the acute and postinfective manifestations of the disease.

Paediatric Active Enhanced Disease Surveillance (PAEDS) 2019: Prospective hospital-based surveillance for serious paediatric conditions

Introduction

The Paediatric Active Enhanced Disease Surveillance (PAEDS) network is an Australian hospital-based active surveillance system employing prospective case ascertainment for selected serious childhood conditions, particularly vaccine preventable diseases and potential adverse events following immunisation (AEFI). This report presents surveillance data for 2019.

Methods

Specialist nurses screened hospital admissions, emergency department records, laboratory and other data on a daily basis in seven paediatric tertiary referral hospitals across Australia, to identify children with the conditions under surveillance. Standardised protocols and case definitions were used across all sites. In 2019, the conditions under surveillance comprised: acute flaccid paralysis (AFP; a syndrome associated with poliovirus infection), acute childhood encephalitis (ACE), influenza, intussusception (IS; a potential AEFI with rotavirus vaccines), pertussis, varicella-zoster virus infection (varicella and herpes zoster), invasive meningococcal and invasive Group A streptococcus diseases and two new conditions, Kawasaki disease and gram-negative bloodstream infections. An additional social research component continued to evaluate parental attitudes to influenza vaccination.

Results

PAEDS captured 2,701 cases for 2019 across all conditions under surveillance. Key outcomes of PAEDS included: contribution to national AFP surveillance to reach the World Health Organization reporting targets for detection of poliomyelitis cases; demonstration of high influenza activity in 2019 and influenza-associated deaths in ACE cases; identification of key barriers to influenza vaccination of children hospitalised for acute respiratory illness; reporting of all IS cases associated with vaccine receipt to relevant state health department; and showing a further reduction nationally in varicella cases. Enhanced pertussis surveillance continued to capture controls to support vaccine efficacy estimation. Invasive meningococcal disease surveillance showed predominance of serotype B and a reduction in cases nationally. Surveillance for invasive group A streptococcus captured severe cases in children. Monitoring of Kawasaki disease incidence and gram-negative bloodstream infections commenced.

Conclusions

PAEDS continues to provide unique policy-relevant data on serious paediatric conditions using sentinel hospital-based enhanced surveillance. Keywords: paediatric, surveillance, child, hospital, vaccine preventable diseases, adverse event following immunisation, acute flaccid paralysis, encephalitis, influenza, intussusception, pertussis, varicella zoster virus, meningococcal, group A streptococcus, Kawasaki, bloodstream infections.

From program suspension to the pandemic: A qualitative examination of Australia's vaccine pharmacovigilance system over 10 years

BACKGROUND

In 2010, the Australian seasonal influenza vaccination program for children under 5 years of age was suspended due to an unexpected increase in fever and febrile convulsions causally associated with one particular influenza vaccine brand. A subsequent national review made seven recommendations to improve vaccine pharmacovigilance. Ten years on, in advance of implementing the COVID-19 immunisation program, we evaluated views on the capacity of Australia's vaccine pharmacovigilance system to promptly detect, examine and communicate a signal.

METHODS

Semi-structured interviews were conducted between July and October 2020 with individuals with expertise in vaccine safety in Australia using an interview guide informed by key Australian and international frameworks. Interviews were digitally recorded and transcribed verbatim. Thematic analysis was used to code data using a deductive approach.

RESULTS

Interviews with seventeen participants enabled six themes to be identified. Participants described improvement and significant innovation within Australia's vaccine pharmacovigilance system over the decade since 2010, particularly through establishment of a new active, cohort event monitoring system using short message service surveys. Participants thought Australia had a good foundation for COVID-19 vaccine safety surveillance; implementation of the COVID-19 immunisation program was seen as a potential driver for ongoing enhancement through: a) improved integration of the active surveillance and spontaneous reporting systems, and; b) development of population-level active surveillance, including through data linkage. Transparent communication was considered essential to address the unprecedented challenges of COVID-19 and broader vaccine safety concerns.

CONCLUSIONS

Vaccine safety experts in Australia convey confidence in the innovative pharmacovigilance systems implemented over the past 10 years. While Australia has a multifaceted system incorporating both active surveillance and spontaneous reporting systems, COVID-19 vaccine implementation represents an opportunity to enhance current systems and to develop new, systematic approaches to vaccine pharmacovigilance that should make both a local and global contribution.

Influenza hospitalizations in children under 1 year old in Spain: the importance of maternal immunization

This study estimates the burden of influenza in infants up to 12 months of age in Spain over 8 seasons (2009/10-2016/17). The survey was conducted by reviewing the Spanish Surveillance System for Hospital Data. Over the eight seasons, 5,618 hospital admissions were recorded for patients younger than 12 months that included codes related to influenza in any diagnostic position (487-488 ICD-9-CM and J9, J10 and J11 CIE 10). In total, 2,363 admissions (42.1%) were female patients whose median age was 3.05 months. Patients younger than 6 months accounted for 3,856 admissions (68.6%). Among them, 59.2% were male, and 40.8% were female (p < .05). Overall, 37.1% (2,084 patients) were younger than 2 months. The hospitalization rate for the entire period studied was 156.09 admissions per 100,000 children under 12 months of age (95% CI: 152.4-160.6). The average duration of hospitalization was 6.6 days (95% CI: 6.4-6.8). Eighteen deaths were recorded for hospitalized patients over the entire period. Of these, 12 patients (66.7%) were younger than 6 months. There is a significant burden of influenza disease in children under 1 year of age in Spain, mainly in children under 6 months of age. Improvements to prevention strategies through increased vaccination coverage in family environments and vaccination strategies involving pregnant woman can contribute decisively and effectively to reducing these hospitalizations.