Maria Yui Kwan Chow

Impacts on influenza A(H1N1)pdm09 infection from cross-protection of seasonal trivalent influenza vaccines and A(H1N1)pdm09 vaccines: systematic review and meta-analyses.

Cross-protection by seasonal trivalent influenza vaccines (TIVs) against pandemic influenza A H1N1 2009 (now known as A[H1N1]pdm09) infection is controversial; and the vaccine effectiveness (VE) of A(H1N1)pdm09 vaccines has important health-policy implications. Systematic reviews and meta-analyses are needed to assess the impacts of both seasonal TIVs and A(H1N1)pdm09 vaccines against A(H1N1)pdm09.We did a systematic literature search to identify observational and/or interventional studies reporting cross-protection of TIV and A(H1N1)pdm09 VE from when the pandemic started (2009) until July 2011. The studies fulfilling inclusion criteria were meta-analysed. For cross-protection and VE, respectively, we stratified by vaccine type, study design and endpoint. Seventeen studies (104,781 subjects) and 10 studies (2,906,860 subjects), respectively, reported cross-protection of seasonal TIV and VE of A(H1N1)pdm09 vaccines; six studies (17,229 subjects) reported on both. Thirteen studies (95,903 subjects) of cross-protection, eight studies (859,461 subjects) of VE, and five studies (9,643 subjects) of both were meta-analysed and revealed: (1) cross-protection for confirmed illness was 19% (95% confident interval=13-42%) based on 13 case-control studies with notable heterogeneity. A higher cross-protection of 34% (9-52%) was found in sensitivity analysis (excluding five studies with moderate/high risk of bias). Further exclusion of studies that recruited early in the pandemic (when non-recipients of TIV were more likely to have had non-pandemic influenza infection that may have been cross-protective) dramatically reduced heterogeneity. One RCT reported cross-protection of 38% (19-53%) for confirmed illness. One case-control study reported cross-protection of 50% (40-59%) against hospitalisation. (2) VE of A(H1N1)pdm09 for confirmed illness was 86% (73-93%) based on 11 case-control studies and 79% (22-94%) based on two cohort studies; VE against medically-attended ILI was 32% (8-50%) in one cohort study. TIVs provided moderate cross-protection against both laboratory-confirmed A(H1N1)pdm09 illness (based on eight case-control studies with low risk of bias and one RCT) and also hospitalisation. A finding of increased risk from seasonal vaccine was limited to cases recruited early in the pandemic. A(H1N1)pdm09 vaccines were highly effective against confirmed A(H1N1)pdm09 illness. Although cross-protection was less than the direct effect of strain-specific vaccination against A(H1N1)pdm09, TIV was generally beneficial before A(H1N1)pdm09 vaccine was available.

Implementation of mandatory immunisation of healthcare workers: Observations from New South Wales, Australia

OBJECTIVE To identify factors influencing implementation of a state-wide mandatory immunisation policy for healthcare workers (HCWs) in New South Wales (NSW), Australia, in 2007. Vaccines included were measles, mumps, rubella, varicella, hepatitis B, diphtheria, tetanus and pertussis, but not influenza. METHODS We evaluated the first 2 years of this policy directive in 2009. A qualitative study was conducted among 4 stakeholder groups (the central health department, hospitals, health professional associations, and universities). 58 participants were identified using maximum variation sampling and data were analysed using a hierarchical thematic framework. Quantitative data on policy compliance were reviewed at the regional level. RESULTS Success in policy implementation was associated with effective communication, including support of clinical leaders, provision of free vaccine, access to occupational health services which included immunisation, and appropriate data collection and reporting systems. Achieving high vaccine uptake was more challenging with existing employees and with smaller institutions. CONCLUSION These findings may apply to other jurisdictions in Australia or internationally considering mandatory approaches to HCW vaccination.

Strategies to improve vaccination uptake in Australia, a systematic review of types and effectiveness

Objective: To identify and critique interventions to improve vaccination uptake in Australia.

Condition-specific quality of life questionnaires for caregivers of children with pediatric conditions: a systematic review

PurposeChildhood illness or disability can affect the quality of life (QoL) of the child’s primary caregiver. Our aim was to identify, describe the content and systematically review the psychometric properties of condition-specific QoL questionnaires for caregivers of children.MethodsMedline, PsycInfo, Embase, CINAHL, and the Cochrane library databases were searched from 1 January 1990 to 30 June 2011. Articles related to the development and measurement of caregiver QoL were screened to identify condition-specific questionnaires. The characteristics of the questionnaires were extracted, and their psychometric properties were evaluated using the consensus-based standards for the selection of health measurement instruments checklist with 4-point scale.ResultsWe identified 25 condition-specific caregiver QoL questionnaires covering 16 conditions. Conditions included atopic dermatitis, asthma, diabetes, oro-facial disorders, and two acute illnesses. Questionnaires were developed predominantly in high-income countries. Questionnaires had the highest quality rating for content validity, followed by hypothesis testing. Methodological quality was satisfactory for criterion validity; fair in reliability and responsiveness; and poor in internal consistency and structural validity.ConclusionsThe increasing number of questionnaires developed over time shows improved recognition of the importance of caregiver QoL. There is a paucity of QoL questionnaires for caregivers of otherwise healthy children suffering from physical injuries and acute conditions associated with significant caregiver burden. Cultural validation of existing and new questionnaires in lower-income countries is necessary. Data collected by condition-specific questionnaires can assist clinicians and health economists in estimating caregiver burden and the types of healthcare services caregivers require and may be useful for healthcare administrators to evaluate interventions.

Estimates and determinants of economic impacts from influenza-like illnesses caused by respiratory viruses in Australian children attending childcare: a cohort study.

Influenza and other respiratory infections cause excess winter morbidity in children. This study assessed the economic impact of influenza‐like illness (ILI) on families with children attending childcare using a societal perspective.

Epidemiology of respiratory viral infections in children enrolled in a study of influenza vaccine effectiveness

Influenza‐like illness (ILI) confers a high annual morbidity in young children. We report the epidemiology of ILIs in children who participated in an influenza vaccine effectiveness study during the 2010 Southern Hemisphere influenza season in Sydney, Australia.

Global Childhood Deaths From Pertussis: A Historical Review

Impact of pertussis vaccines on mortality is a key World Health Organization indicator, and trends in mortality rates and age distribution can inform maternal immunization strategies. We systematically reviewed studies reporting pertussis mortality rates (PMRs) per million population, identifying 19 eligible studies. During a prevaccine observation period of ≥50 years in high-income countries (HICs), PMRs reduced in both infants and 1- to 4-year-olds by >80%, along with improvements in living conditions. In studies in low- and middle-income countries (LMICs), PMRs resembled highest prevaccine HIC rates. Postvaccine in HICs, significant further reduction in deaths (>98%) occurred, but with a large left shift in age of onset among residual deaths. Postvaccine in LMICs, limited data also show large and rapid decreases in PMRs, first in older infants and children, but long-term data fully enumerating residual deaths are lacking. In Sweden, large increases in the prevalence of undetectable pertussis antibodies were found at 10 years after high childhood coverage of acellular pertussis vaccines. Such data are not available from LMICs using whole-cell vaccines in a primary schedule without boosters. Data on residual infant deaths and maternal seroprevalence would be valuable inputs into consideration of pertussis vaccination in pregnancy in LMIC settings, especially if more precise immune correlates of infant protection against death from pertussis were known.

Impact of children's influenza-like illnesses on parental quality of life: A qualitative study

Influenza and influenza‐like illness (ILI) in otherwise healthy children has considerable impact on their parents. This study explored the impact of childrens ILI on parental quality of life (QoL).