1
|
Jones CH, Hauguel T, Beitelshees M, Davitt M, Welch V, Lindert K, Allen P, True JM, Dolsten M. Deciphering immune responses: a comparative analysis of influenza vaccination platforms. Drug Discov Today 2024:104125. [PMID: 39097221 DOI: 10.1016/j.drudis.2024.104125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 06/21/2024] [Accepted: 07/29/2024] [Indexed: 08/05/2024]
Abstract
Influenza still poses a significant challenge due to its high mutation rates and the low effectiveness of traditional vaccines. At present, antibodies that neutralize the highly variable hemagglutinin antigen are a major driver of the observed variable protection. To decipher how influenza vaccines can be improved, an analysis of licensed vaccine platforms was conducted, contrasting the strengths and limitations of their different mechanisms of protection. Through this review, it is evident that these vaccines do not elicit the robust cellular immune response critical for protecting high-risk groups. Emerging platforms, such as RNA vaccines, that induce robust cellular responses that may be additive to the recognized mechanism of protection through hemagglutinin inhibition may overcome these constraints to provide broader, protective immunity. By combining both humoral and cellular responses, such platforms could help guide the future influenza vaccine development.
Collapse
Affiliation(s)
| | | | | | | | - Verna Welch
- Pfizer, Hudson Boulevard, New York, NY 10018, USA
| | | | - Pirada Allen
- Pfizer, Hudson Boulevard, New York, NY 10018, USA
| | - Jane M True
- Pfizer, Hudson Boulevard, New York, NY 10018, USA.
| | | |
Collapse
|
2
|
Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V. Vaccines for preventing influenza in healthy children. Cochrane Database Syst Rev 2018; 2:CD004879. [PMID: 29388195 PMCID: PMC6491174 DOI: 10.1002/14651858.cd004879.pub5] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND The consequences of influenza in children and adults are mainly absenteeism from school and work. However, the risk of complications is greatest in children and people over 65 years of age. This is an update of a review published in 2011. Future updates of this review will be made only when new trials or vaccines become available. Observational data included in previous versions of the review have been retained for historical reasons but have not been updated because of their lack of influence on the review conclusions. OBJECTIVES To assess the effects (efficacy, effectiveness, and harm) of vaccines against influenza in healthy children. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 12), which includes the Cochrane Acute Respiratory Infections Group Specialised Register, MEDLINE (1966 to 31 December 2016), Embase (1974 to 31 December 2016), WHO International Clinical Trials Registry Platform (ICTRP; 1 July 2017), and ClinicalTrials.gov (1 July 2017). SELECTION CRITERIA Randomised controlled trials comparing influenza vaccines with placebo or no intervention in naturally occurring influenza in healthy children under 16 years. Previous versions of this review included 19 cohort and 11 case-control studies. We are no longer updating the searches for these study designs but have retained the observational studies for historical purposes. DATA COLLECTION AND ANALYSIS Review authors independently assessed risk of bias and extracted data. We used GRADE to rate the certainty of evidence for the key outcomes of influenza, influenza-like illness (ILI), complications (hospitalisation, ear infection), and adverse events. Due to variation in control group risks for influenza and ILI, absolute effects are reported as the median control group risk, and numbers needed to vaccinate (NNVs) are reported accordingly. For other outcomes aggregate control group risks are used. MAIN RESULTS We included 41 clinical trials (> 200,000 children). Most of the studies were conducted in children over the age of two and compared live attenuated or inactivated vaccines with placebo or no vaccine. Studies were conducted over single influenza seasons in the USA, Western Europe, Russia, and Bangladesh between 1984 and 2013. Restricting analyses to studies at low risk of bias showed that influenza and otitis media were the only outcomes where the impact of bias was negligible. Variability in study design and reporting impeded meta-analysis of harms outcomes.Live attenuated vaccinesCompared with placebo or do nothing, live attenuated influenza vaccines probably reduce the risk of influenza infection in children aged 3 to 16 years from 18% to 4% (risk ratio (RR) 0.22, 95% confidence interval (CI) 0.11 to 0.41; 7718 children; moderate-certainty evidence), and they may reduce ILI by a smaller degree, from 17% to 12% (RR 0.69, 95% CI 0.60 to 0.80; 124,606 children; low-certainty evidence). Seven children would need to be vaccinated to prevent one case of influenza, and 20 children would need to be vaccinated to prevent one child experiencing an ILI. Acute otitis media is probably similar following vaccine or placebo during seasonal influenza, but this result comes from a single study with particularly high rates of acute otitis media (RR 0.98, 95% CI 0.95 to 1.01; moderate-certainty evidence). There was insufficient information available to determine the effect of vaccines on school absenteeism due to very low-certainty evidence from one study. Vaccinating children may lead to fewer parents taking time off work, although the CI includes no effect (RR 0.69, 95% CI 0.46 to 1.03; low-certainty evidence). Data on the most serious consequences of influenza complications leading to hospitalisation were not available. Data from four studies measuring fever following vaccination varied considerably, from 0.16% to 15% in children who had live vaccines, while in the placebo groups the proportions ranged from 0.71% to 22% (very low-certainty evidence). Data on nausea were not reported.Inactivated vaccinesCompared with placebo or no vaccination, inactivated vaccines reduce the risk of influenza in children aged 2 to 16 years from 30% to 11% (RR 0.36, 95% CI 0.28 to 0.48; 1628 children; high-certainty evidence), and they probably reduce ILI from 28% to 20% (RR 0.72, 95% CI 0.65 to 0.79; 19,044 children; moderate-certainty evidence). Five children would need to be vaccinated to prevent one case of influenza, and 12 children would need to be vaccinated to avoid one case of ILI. The risk of otitis media is probably similar between vaccinated children and unvaccinated children (31% versus 27%), although the CI does not exclude a meaningful increase in otitis media following vaccination (RR 1.15, 95% CI 0.95 to 1.40; 884 participants; moderate-certainty evidence). There was insufficient information available to determine the effect of vaccines on school absenteeism due to very low-certainty evidence from one study. We identified no data on parental working time lost, hospitalisation, fever, or nausea.We found limited evidence on secondary cases, requirement for treatment of lower respiratory tract disease, and drug prescriptions. One brand of monovalent pandemic vaccine was associated with a sudden loss of muscle tone triggered by the experience of an intense emotion (cataplexy) and a sleep disorder (narcolepsy) in children. Evidence of serious harms (such as febrile fits) was sparse. AUTHORS' CONCLUSIONS In children aged between 3 and 16 years, live influenza vaccines probably reduce influenza (moderate-certainty evidence) and may reduce ILI (low-certainty evidence) over a single influenza season. In this population inactivated vaccines also reduce influenza (high-certainty evidence) and may reduce ILI (low-certainty evidence). For both vaccine types, the absolute reduction in influenza and ILI varied considerably across the study populations, making it difficult to predict how these findings translate to different settings. We found very few randomised controlled trials in children under two years of age. Adverse event data were not well described in the available studies. Standardised approaches to the definition, ascertainment, and reporting of adverse events are needed. Identification of all global cases of potential harms is beyond the scope of this review.
Collapse
Affiliation(s)
- Tom Jefferson
- University of OxfordCentre for Evidence Based MedicineOxfordUKOX2 6GG
| | - Alessandro Rivetti
- ASL CN2 Alba BraDipartimento di Prevenzione ‐ S.Pre.S.A.LVia Vida 10AlbaPiemonteItaly12051
| | - Carlo Di Pietrantonj
- Local Health Unit Alessandria‐ ASL ALRegional Epidemiology Unit SeREMIVia Venezia 6AlessandriaAlessandriaItaly15121
| | - Vittorio Demicheli
- Azienda Sanitaria Locale ASL ALServizio Regionale di Riferimento per l'Epidemiologia, SSEpi‐SeREMIVia Venezia 6AlessandriaPiemonteItaly15121
| | | |
Collapse
|
3
|
Su WJ, Chan TC, Chuang PH, Liu YL, Lee PI, Liu MT, Chuang JH. Estimating influenza vaccine effectiveness using routine surveillance data among children aged 6-59 months for five consecutive influenza seasons. Int J Infect Dis 2014; 30:115-21. [PMID: 25462180 PMCID: PMC7110782 DOI: 10.1016/j.ijid.2014.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 11/10/2014] [Accepted: 11/12/2014] [Indexed: 11/28/2022] Open
Abstract
Multiyear studies are preferred for estimating robust influenza vaccine effectiveness over time. An efficient way to evaluate the influenza vaccine effectiveness was used, through data linkage of two already established systems in the public health sector. We applied both fixed-effects and random-effects meta-analysis of case–control studies to estimate the pooled vaccine effectiveness for children aged 6–59 months across five influenza seasons and considered the variation in antigenic match and epidemics year by year as the heterogeneity between studies.
Objectives We aimed to estimate the pooled vaccine effectiveness (VE) in children over five winters through data linkage of two existing surveillance systems. Methods Five test-negative case–control studies were conducted from November to February during the 2004/2005 to 2008/2009 seasons. Sentinel physicians from the Viral Surveillance Network enrolled children aged 6–59 months with influenza-like illness to collect throat swabs. Through linking with a nationwide vaccination registry, we measured the VE with a logistic regression model adjusting for age, gender, and week of symptom onset. Both fixed-effects and random-effects models were used in the meta-analysis. Results Four thousand four hundred and ninety-four subjects were included. The proportion of influenza test-positive subjects across the five seasons was 11.5% (132/1151), 7.2% (41/572), 23.9% (189/791), 6.6% (75/1135), and 11.2% (95/845), respectively. The pooled VE was 62% (95% confidence interval (CI) 48–83%) in both meta-analysis models. By age category, VE was 51% (95% CI 23–68%) for those aged 6–23 months and 75% (95% CI 60–84%) for those aged 24–59 months. Conclusions Influenza vaccination provided measurable protection against laboratory-confirmed influenza among children aged 6–59 months despite variations in the vaccine match during the 2004/2005 to 2008/2009 influenza seasons in Taiwan.
Collapse
Affiliation(s)
- Wei-Ju Su
- Centers for Disease Control, Ministry of Health and Welfare, Taipei 10050, Taiwan; Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan; Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Ta-Chien Chan
- Research Center for Humanities and Social Sciences, Academia Sinica, Taipei, Taiwan
| | | | - Yu-Lun Liu
- Centers for Disease Control, Ministry of Health and Welfare, Taipei 10050, Taiwan
| | - Ping-Ing Lee
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Tsan Liu
- Centers for Disease Control, Ministry of Health and Welfare, Taipei 10050, Taiwan.
| | - Jen-Hsiang Chuang
- Centers for Disease Control, Ministry of Health and Welfare, Taipei 10050, Taiwan; Institute of Health Care Administration, National Yang-Ming University, Taipei, Taiwan.
| |
Collapse
|
4
|
Simpson CR, Lone N, Kavanagh K, Ritchie LD, Robertson C, Sheikh A, McMenamin J. Seasonal Influenza Vaccine Effectiveness (SIVE): an observational retrospective cohort study – exploitation of a unique community-based national-linked database to determine the effectiveness of the seasonal trivalent influenza vaccine. HEALTH SERVICES AND DELIVERY RESEARCH 2013. [DOI: 10.3310/hsdr01100] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BackgroundGlobally, seasonal influenza is responsible for an estimated 3 to 5 million cases of severe illness and 250,000 to 500,000 deaths per year. It is uncertain to what extent national vaccination programmes can prevent this morbidity and mortality.ObjectiveTo determine the effectiveness of the seasonal trivalent inactivated influenza vaccine.DesignWe undertook a retrospective observational cohort study. A propensity score model was constructed and adjusted odds ratios (ORs) were calculated to assess differences in vaccine uptake according to a number of patient characteristics. Adjusted illness and mortality hazard ratios (HRs) were estimated from a Cox proportional hazards model adjusted for sex, age, socioeconomic status, smoking status, urban/rural location, clinical at-risk groups (i.e. patients with chronic respiratory, heart, kidney, liver or neurological disease, immunosuppression and diabetes), Charlson comorbidity index, previous pneumococcal and influenza vaccination, and number of previous primary care consultations, prescribed drugs and hospital admissions. We also included nursing home residence and social care support. Vaccine effectiveness (VE) was expressed as a percentage, and represents a reduction in risk provided by the vaccine for a given outcome (e.g. laboratory-confirmed influenza). This was calculated as 1 − HR, where HR is that of the measured clinical outcome in vaccinated compared with unvaccinated individuals. For estimates of VE derived from linked virological swab data, we carried out a nested case–control study design.SettingA national linkage of patient-level primary care, hospital, death certification and virological swab-linked data across nine influenza seasons (2000–9).ParticipantsA nationally representative sample of the Scottish population during 1,767,919 person-seasons of observation. Cases of influenza were confirmed using reverse transcription-polymerase chain reaction (RT-PCR) in a subset of the population (n = 3323).InterventionsTrivalent inactivated seasonal influenza vaccination (n = 274,071).Main outcome measuresVE, pooled across seasons and adjusting for confounders, was estimated by determining laboratory-confirmed influenza, influenza-related morbidity and mortality including primary care influenza-like illnesses, hospitalisation and death from influenza and pneumonia.ResultsMost vaccines (93.6%;n = 256,474 vaccines) were administered to at-risk patients targeted for vaccination, with a 69.3% uptake among those aged ≥ 65 years (178,754 vaccinations during 258,100 person-seasons). For at-risk patients aged < 65 years there was a 26.2% uptake (77,264 vaccinations during 295,116 person-seasons). VE in preventing RT-PCR laboratory-confirmed influenza was 57.1% [95% confidence interval (CI) 31.3% to 73.3%]. VE was 18.8% (95% CI –103.7% to 67.6%) in patients aged ≥ 65 years and 59.6% (95% CI 21.9% to 79.1%) in those aged < 65 years at risk of serious complications from influenza. In the matched analysis (156,096 person-seasons), adjusted VE for reducing primary care consultations for influenza-like illnesses was 16.3% (95% CI 5.7% to 26.0%). VE in reducing hospitalisations was 19.3% for influenza and pneumonia (95% CI 8.3% to 29.1%) and 26.7% for pneumonia and chronic obstructive pulmonary disease (95% CI 19.8% to 32.9%). VE in reducing death due to influenza and pneumonia was 37.9% (95% CI 29.5% to 45.4%).ConclusionsFew countries' health systems allow for the integrated and accessible data recording that made this study possible and made it feasible to collate centrally almost all hospitalisations and deaths attributed to influenza, thereby allowing completeness of reporting. Using these data, we found most influenza vaccines were administered to those at risk of serious complications from influenza. In a nationally representative cohort we found that the vaccine was associated with a significant decrease in the risk of RT-PCR-confirmed influenza (the decrease was substantial particularly for at-risk patients aged < 65 years) and complications arising from influenza (where more modest decreases were found). Although the modest size of our cohort made it possible to collate centrally almost all cases of influenza-related disease, analysis of subgroups (in particular older age groups) or by individual season resulted in poorer precision and wide CIs. Any future work should therefore aim to address this issue by ensuring adequate power to test VE in these subgroups of patients, while minimising the effect of bias, such as health-seeking behaviour.FundingThe National Institute for Health Research Health Services and Delivery Research programme.
Collapse
Affiliation(s)
- CR Simpson
- Allergy and Respiratory Research Group, Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - N Lone
- Allergy and Respiratory Research Group, Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - K Kavanagh
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
| | - LD Ritchie
- Centre of Academic Primary Care, University of Aberdeen, Aberdeen, UK
| | - C Robertson
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
- Health Protection Scotland, Glasgow, UK
- International Prevention Research Institute, Lyon, France
| | - A Sheikh
- Allergy and Respiratory Research Group, Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
- School of Public Health and Primary Care (CAPHRI), University of Maastricht, Maastricht, the Netherlands
| | | |
Collapse
|
5
|
Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database Syst Rev 2012; 2012:CD004879. [PMID: 22895945 PMCID: PMC6478137 DOI: 10.1002/14651858.cd004879.pub4] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The consequences of influenza in children and adults are mainly absenteeism from school and work. However, the risk of complications is greatest in children and people over 65 years of age. OBJECTIVES To appraise all comparative studies evaluating the effects of influenza vaccines in healthy children, assess vaccine efficacy (prevention of confirmed influenza) and effectiveness (prevention of influenza-like illness (ILI)) and document adverse events associated with influenza vaccines. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 3) which includes the Acute Respiratory Infections Group's Specialised Register, OLD MEDLINE (1950 to 1965), MEDLINE (1966 to November 2011), EMBASE (1974 to November 2011), Biological Abstracts (1969 to September 2007), and Science Citation Index (1974 to September 2007). SELECTION CRITERIA Randomised controlled trials (RCTs), cohort and case-control studies of any influenza vaccine in healthy children under 16 years of age. DATA COLLECTION AND ANALYSIS Four review authors independently assessed trial quality and extracted data. MAIN RESULTS We included 75 studies with about 300,000 observations. We included 17 RCTs, 19 cohort studies and 11 case-control studies in the analysis of vaccine efficacy and effectiveness. Evidence from RCTs shows that six children under the age of six need to be vaccinated with live attenuated vaccine to prevent one case of influenza (infection and symptoms). We could find no usable data for those aged two years or younger.Inactivated vaccines in children aged two years or younger are not significantly more efficacious than placebo. Twenty-eight children over the age of six need to be vaccinated to prevent one case of influenza (infection and symptoms). Eight need to be vaccinated to prevent one case of influenza-like-illness (ILI). We could find no evidence of effect on secondary cases, lower respiratory tract disease, drug prescriptions, otitis media and its consequences and socioeconomic impact. We found weak single-study evidence of effect on school absenteeism by children and caring parents from work. Variability in study design and presentation of data was such that a meta-analysis of safety outcome data was not feasible. Extensive evidence of reporting bias of safety outcomes from trials of live attenuated influenza vaccines (LAIVs) impeded meaningful analysis. One specific brand of monovalent pandemic vaccine is associated with cataplexy and narcolepsy in children and there is sparse evidence of serious harms (such as febrile convulsions) in specific situations. AUTHORS' CONCLUSIONS Influenza vaccines are efficacious in preventing cases of influenza in children older than two years of age, but little evidence is available for children younger than two years of age. There was a difference between vaccine efficacy and effectiveness, partly due to differing datasets, settings and viral circulation patterns. No safety comparisons could be carried out, emphasising the need for standardisation of methods and presentation of vaccine safety data in future studies. In specific cases, influenza vaccines were associated with serious harms such as narcolepsy and febrile convulsions. It was surprising to find only one study of inactivated vaccine in children under two years, given current recommendations to vaccinate healthy children from six months of age in the USA, Canada, parts of Europe and Australia. If immunisation in children is to be recommended as a public health policy, large-scale studies assessing important outcomes, and directly comparing vaccine types are urgently required. The degree of scrutiny needed to identify all global cases of potential harms is beyond the resources of this review. This review includes trials funded by industry. An earlier systematic review of 274 influenza vaccine studies published up to 2007 found industry-funded studies were published in more prestigious journals and cited more than other studies independently from methodological quality and size. Studies funded from public sources were significantly less likely to report conclusions favourable to the vaccines. The review showed that reliable evidence on influenza vaccines is thin but there is evidence of widespread manipulation of conclusions and spurious notoriety of the studies. The content and conclusions of this review should be interpreted in the light of this finding.
Collapse
|
6
|
Lone NI, Simpson C, Kavanagh K, Robertson C, McMenamin J, Ritchie L, Sheikh A. Seasonal Influenza Vaccine Effectiveness in the community (SIVE): protocol for a cohort study exploiting a unique national linked data set. BMJ Open 2012; 2:e001019. [PMID: 22422920 PMCID: PMC3307124 DOI: 10.1136/bmjopen-2012-001019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
INTRODUCTION Seasonal influenza vaccination is recommended for all individuals aged 65 years and over and in individuals younger than 65 years with comorbidities. There is good evidence of vaccine effectiveness (VE) in young healthy individuals but less robust evidence for effectiveness in the populations targeted for influenza vaccination. Undertaking a randomised controlled trial to assess VE is now impractical due to the presence of national vaccination programmes. Quasi-experimental designs offer the potential to advance the evidence base in such scenarios, and the authors have therefore been commissioned to undertake a naturalistic national evaluation of seasonal influenza VE by using data derived from linkage of a number of Scottish health databases. The aim of this study is to examine the effectiveness of the seasonal influenza vaccination in the Scottish population. METHODS AND ANALYSIS A cohort study design will be used pooling data over nine seasons. A primary care database covering 4% of the Scottish population for the period 2000-2009 has been linked to the national database of hospital admissions and the death register and is being linked to the Health Protection Scotland virology database. The primary outcome is VE measured in terms of rate of hospital admissions due to respiratory illness. Multivariable regression will be used to produce estimates of VE adjusted for confounders. The major challenge of this approach is addressing the strong effect of confounding due to vaccinated individuals being systematically different from unvaccinated individuals. Analyses using propensity scores and instrumental variables will be undertaken, and the effect of an unknown confounder will be modelled in a sensitivity analysis to assess the robustness of the estimates. ETHICS AND DISSEMINATION The West of Scotland Research Ethics Committee has classified this project as surveillance. The study findings will be disseminated in peer-reviewed publications and presented at international conferences.
Collapse
Affiliation(s)
- Nazir I Lone
- Centre for Population Health Sciences, The University of Edinburgh, Edinburgh, UK
| | - Colin Simpson
- Centre for Population Health Sciences, The University of Edinburgh, Edinburgh, UK
| | - Kimberley Kavanagh
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
| | - Chris Robertson
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
- Health Protection Scotland, Glasgow, UK
| | | | - Lewis Ritchie
- Centre of Academic Primary Care, University of Aberdeen, Aberdeen, UK
| | - Aziz Sheikh
- Centre for Population Health Sciences, The University of Edinburgh, Edinburgh, UK
| |
Collapse
|
7
|
The use of a mandatory best practice reminder in the electronic record improves influenza vaccination rate in a pediatric rheumatology clinic. ACTA ACUST UNITED AC 2011. [DOI: 10.1108/14777271111175350] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PurposeChildren with rheumatic disease, who are infected with influenza, have an increased rate of complications. These complications can be reduced by improving the flu vaccination rate. This paper's aim is to document the authors' purpose of increasing the influenza vaccination rate through information technology (IT) intervention in this high risk population of patients.Design/methodology/approachThe authors retrospectively reviewed the electronic health records (EHR) of three yearly cohorts (2007, 2008, and 2009) of rheumatology clinic patients from a large pediatric hospital for evidence of influenza vaccination. They introduced an automatic best practice reminder intervention in patients' EHR from September 2009 to April 2010. Using Clarity Report Write for EPIC, each chart was examined for evidence of influenza vaccination to test for vaccination rate difference among the cohorts. The authors employed logistic regression equations to control for possible confounders using SAS 9.1.3.FindingsThere was a significant difference in the probability of being vaccinated before and after intervention (p value <0.0001).The vaccination rate increased from 5.9 percent in 2007, 7.8 percent in 2008 and to 25.5 percent in 2009. During all three years, individual attending's contribution and ethnicity of patients had significant effects on vaccination rate. Confounders such as age, sex, insurance status and distance travelled from clinic had no effect on the vaccination rate.Originality/valueEHR‐embedded information in past studies has been only modestly effective in improving care for many chronic conditions. The automatic best practice reminder for flu‐vaccine appears to be effective for changing physician's behaviors and improving the vaccination rate in rheumatology clinics.
Collapse
|
8
|
Statement on Seasonal Influenza Vaccine for 2011-2012: An Advisory Committee Statement (ACS) National Advisory Committee on Immunization (NACI) †. CANADA COMMUNICABLE DISEASE REPORT = RELEVE DES MALADIES TRANSMISSIBLES AU CANADA 2011; 37:1-55. [PMID: 31682646 PMCID: PMC6802429 DOI: 10.14745/ccdr.v37i00a05] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
9
|
Nishiura H, Oshitani H. Effects of vaccination against pandemic (H1N1) 2009 among Japanese children. Emerg Infect Dis 2011; 17:746-7. [PMID: 21470479 DOI: 10.3201/eid1706.100525] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
10
|
|
11
|
Jefferson T, Del Mar CB, Dooley L, Ferroni E, Al‐Ansary LA, Bawazeer GA, van Driel ML, Nair NS, Jones MA, Thorning S, Conly JM. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database Syst Rev 2011; 2011:CD006207. [PMID: 21735402 PMCID: PMC6993921 DOI: 10.1002/14651858.cd006207.pub4] [Citation(s) in RCA: 242] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Viral epidemics or pandemics of acute respiratory infections like influenza or severe acute respiratory syndrome pose a global threat. Antiviral drugs and vaccinations may be insufficient to prevent their spread. OBJECTIVES To review the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. SEARCH STRATEGY We searched The Cochrane Library, the Cochrane Central Register of Controlled Trials (CENTRAL 2010, Issue 3), which includes the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to October 2010), OLDMEDLINE (1950 to 1965), EMBASE (1990 to October 2010), CINAHL (1982 to October 2010), LILACS (2008 to October 2010), Indian MEDLARS (2008 to October 2010) and IMSEAR (2008 to October 2010). SELECTION CRITERIA In this update, two review authors independently applied the inclusion criteria to all identified and retrieved articles and extracted data. We scanned 3775 titles, excluded 3560 and retrieved full papers of 215 studies, to include 66 papers of 67 studies. We included physical interventions (screening at entry ports, isolation, quarantine, social distancing, barriers, personal protection, hand hygiene) to prevent respiratory virus transmission. We included randomised controlled trials (RCTs), cohorts, case-controls, before-after and time series studies. DATA COLLECTION AND ANALYSIS We used a standardised form to assess trial eligibility. We assessed RCTs by randomisation method, allocation generation, concealment, blinding and follow up. We assessed non-RCTs for potential confounders and classified them as low, medium and high risk of bias. MAIN RESULTS We included 67 studies including randomised controlled trials and observational studies with a mixed risk of bias. A total number of participants is not included as the total would be made up of a heterogenous set of observations (participant people, observations on participants and countries (object of some studies)). The risk of bias for five RCTs and most cluster-RCTs was high. Observational studies were of mixed quality. Only case-control data were sufficiently homogeneous to allow meta-analysis. The highest quality cluster-RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children. Benefit from reduced transmission from children to household members is broadly supported also in other study designs where the potential for confounding is greater. Nine case-control studies suggested implementing transmission barriers, isolation and hygienic measures are effective at containing respiratory virus epidemics. Surgical masks or N95 respirators were the most consistent and comprehensive supportive measures. N95 respirators were non-inferior to simple surgical masks but more expensive, uncomfortable and irritating to skin. Adding virucidals or antiseptics to normal handwashing to decrease respiratory disease transmission remains uncertain. Global measures, such as screening at entry ports, led to a non-significant marginal delay in spread. There was limited evidence that social distancing was effective, especially if related to the risk of exposure. AUTHORS' CONCLUSIONS Simple and low-cost interventions would be useful for reducing transmission of epidemic respiratory viruses. Routine long-term implementation of some measures assessed might be difficult without the threat of an epidemic.
Collapse
Affiliation(s)
- Tom Jefferson
- University of OxfordCentre for Evidence Based MedicineOxfordUKOX2 6GG
| | - Chris B Del Mar
- Bond UniversityCentre for Research in Evidence‐Based Practice (CREBP)University DriveGold CoastQueenslandAustralia4229
| | - Liz Dooley
- Bond UniversityFaculty of Health Sciences and MedicineGold CoastQueenslandAustralia4229
| | - Eliana Ferroni
- Regional Center for Epidemiology, Veneto RegionEpidemiological System of the Veneto RegionPassaggio Gaudenzio 1PadovaItaly35131
| | - Lubna A Al‐Ansary
- World Health OrganizationDepartment of Health Metrics and MeasurementGenevaSwitzerland
| | - Ghada A Bawazeer
- King Saud UniversityDepartment of Clinical Pharmacy, College of PharmacyP.O. Box 22452RiyadhSaudi Arabia11495
| | - Mieke L van Driel
- The University of QueenslandPrimary Care Clinical Unit, Faculty of MedicineBrisbaneQueenslandAustralia4029
- Ghent UniversityDepartment of Public Health and Primary CareCampus UZ 6K3, Corneel Heymanslaan 10GhentBelgium9000
| | - N Sreekumaran Nair
- Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER) (Institution of National Importance Under Ministry of Health and Family Welfare, Government of India)Department of Medical Biometrics & Informatics (Biostatistics)4th Floor, Administrative BlockDhanvantri NagarPuducherryIndia605006
| | - Mark A Jones
- Bond UniversityInstitute for Evidence‐Based Healthcare11 University DriveRobinaGold CoastQueenslandAustralia4226
| | - Sarah Thorning
- Gold Coast Hospital and Health ServiceGCUH LibraryLevel 1, Block E, GCUHSouthportQueenslandAustralia4215
| | - John M Conly
- Foothills Medical Centre, Room 930, North Tower1403‐29th St NWCalgaryABCanadaT2N 2T9
- WHO. Infection Prevention and Control in Health CareDepartment of Global Alert and Response ‐ Health Security and EnvironmentOffice L420, 20, Avenue AppiaGenevaSwitzerlandCH‐1211
| | | |
Collapse
|
12
|
Abstract
BACKGROUND Influenza vaccine immunogenicity in premature infants is incompletely characterized. OBJECTIVE To assess the immunogenicity of trivalent, inactivated influenza vaccine (TIV) in extremely low-birth-weight (≤ 1000 g birth weight) premature (<30 weeks gestation) infants. We hypothesized that geometric mean titers of influenza antibody would be lower in premature than in full-term (FT) (≥ 37 week) infants. DESIGN/METHODS In this prospective multicenter study, former premature and FT infants who were 6 to 17 months of age received 2 doses of TIV during the 2006-2007 or 2007-2008 influenza seasons. Sera were drawn before dose 1, and 4 to 6 weeks after dose 2. Antibody was measured by hemagglutination inhibition. RESULTS Over 2 years, 41 premature and 42 FT infants were enrolled; 36 and 33 of these infants, respectively, had postvaccination titers available. Premature infants weighed less (mean, 1.3-1.8 kg difference) at the time of immunization than FT infants. Prevaccination titers did not differ between groups. Premature infants had higher postvaccination antibody geometric mean titers than FT infants to H1 (2006-2007, 1:513 vs. 1:91, P = 0.03; 2007-2008, 1:363 vs. 1:189, P = 0.02) and B/Victoria (2006-2007, 1:51 vs. 1:10, P = 0.02). More premature than FT infants had antibody titers ≥ 1:32 to B/Victoria (85% vs. 60%, P = 0.04) in 2007-2008. Two (5%) premature and 8 (19%) FT infants had adverse events, primarily fever, within 72 hours after vaccination. No child had medically diagnosed influenza. CONCLUSIONS Former premature infants had antibody responses to 2 TIV doses higher than or equal to those of FT children. Two TIV doses are immunogenic and well tolerated in extremely low-birth-weight, premature infants 6 to 17 months old.
Collapse
|
13
|
Van Buynder PG, Dhaliwal JK, Van Buynder JL, Couturier C, Minville-Leblanc M, Garceau R, Tremblay FW. Protective effect of single-dose adjuvanted pandemic influenza vaccine in children. Influenza Other Respir Viruses 2011; 4:171-8. [PMID: 20629771 PMCID: PMC5964543 DOI: 10.1111/j.1750-2659.2010.00146.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Please cite this paper as: Van Buynder et al. (2010) Protective effect of single‐dose adjuvanted pandemic influenza vaccine in children. Influenza and Other Respiratory Viruses 4(4), 171–178. Background During the first wave of A/California/7/2009(H1N1) influenza, high rates of hospitalization in children under 5 years were seen in many countries. Subsequent policies for vaccinating children varied in both type of vaccine and number of doses. In Canada, children 36 months to <10 years received a single dose of 0·25 ml of the GSK adjuvanted vaccine (Arepanrix™) equivalent to 1·9 μg HA. Children 6 months to 35 months received two doses as did those 36–119 months with chronic medical conditions. Method We conducted a community‐based case–control vaccine effectiveness (VE) review of children under 10 years with influenza like illness who were tested for H1N1 infection at the central provincial laboratory. Laboratory‐confirmed influenza was the primary outcome, and vaccination status the primary exposure to assess VE after a single 0·25‐ml dose. Results If vaccination was designated to be effective after 14 days, no vaccinated child had laboratory‐confirmed influenza compared to 38% of controls. The VE of 100% was statistically significant for children <10 years of age and <5 years considered separately. If vaccination was considered effective after 10 days, VE dropped to 96% overall but was statistically significant and over 90% in all age subgroups, including those under 36 months. Conclusions A single 0·25‐ml dose of the GSK adjuvanted vaccine (Arepanrix™) protects children against laboratory‐confirmed pandemic influenza potentially avoiding any increased reactogenicity associated with second doses. Adjuvanted vaccines offer hope for improved seasonal vaccines in the future.
Collapse
Affiliation(s)
- P G Van Buynder
- New Brunswick Department of Health, Office of the Chief Medical Officer of Health (OCMOH), Fredericton, NB, Canada.
| | | | | | | | | | | | | |
Collapse
|
14
|
Dixon GA, Moore HC, Kelly H, Jacoby P, Carcione D, Williams S, Smith D, Keil AD, Van Buynder P, Richmond PC. Lessons from the first year of the WAIVE study investigating the protective effect of influenza vaccine against laboratory-confirmed influenza in hospitalised children aged 6-59 months. Influenza Other Respir Viruses 2011; 4:231-4. [PMID: 20629773 PMCID: PMC5964547 DOI: 10.1111/j.1750-2659.2010.00141.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Influenza is major cause of paediatric hospitalisation. Influenza vaccine was offered to all children aged 6-59 months resident in Western Australia in 2008, and we wished to evaluate the effectiveness of this immunisation programme. OBJECTIVES To assess the practicalities of a nested matched case-control design to estimate the protective effect of inactivated influenza vaccination in hospitalised children aged 6-59 months. METHODS Cases were hospitalised children with laboratory-confirmed influenza, while matched controls were recruited from children admitted for an acute non-respiratory illness. We estimated influenza vaccine effectiveness (VE) against influenza as 1--the adjusted odds ratio from multivariate logistic regression. RESULTS The 2008 influenza season was characterised by a late peak and a predominance of influenza virus B. We recruited 26 hospitalised patients with laboratory-confirmed influenza and 50 matched controls. The proportion of cases who were fully vaccinated was 7% versus 30% of controls giving an adjusted VE of 83% (95% CI--54 to 98). CONCLUSIONS Recruiting sufficient controls was problematic and in the future, we will select controls hospitalised for an influenza-like-illness but influenza negative by laboratory PCR testing. The VE estimate was high but non-significant, reflecting the low number of cases.
Collapse
Affiliation(s)
- Gabriela A Dixon
- Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Australia
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Zhou D, Wu TL, Lasaro MO, Latimer BP, Parzych EM, Bian A, Li Y, Li H, Erikson J, Xiang Z, Ertl HCJ. A universal influenza A vaccine based on adenovirus expressing matrix-2 ectodomain and nucleoprotein protects mice from lethal challenge. Mol Ther 2010; 18:2182-9. [PMID: 20877342 DOI: 10.1038/mt.2010.202] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A universal influenza vaccine, designed to induce broadly cross-reactive immunity against current and future influenza A virus strains, is in critical demand to reduce the need for annual vaccinations with vaccines chosen upon predicting the predominant circulating viral strains, and to ameliorate the threat of cyclically occurring pandemics that have, in the past, killed tens of millions. Here, we describe a vaccine regimen based on sequential immunization with two serologically distinct chimpanzee-derived replication-defective adenovirus (Ad) vectors expressing the matrix-2 protein ectodomain (M2e) from three divergent strains of influenza A virus fused to the influenza virus nucleoprotein (NP) for induction of antibodies to M2e and virus-specific CD8(+) T cells to NP. In preclinical mouse models, the Ad vaccines expressing M2e and NP elicit robust NP-specific CD8(+) T-cell responses and moderate antibody responses to all three M2e sequences. Most importantly, vaccinated mice are protected against morbidity and mortality following challenge with high doses of different influenza virus strains. Protection requires both antibodies to M2e and cellular immune responses to NP.
Collapse
Affiliation(s)
- Dongming Zhou
- The Wistar Institute, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Statement on Seasonal Trivalent Inactivated Influenza Vaccine (TIV) for 2010-2011: An Advisory Committee Statement (ACS) National Advisory Committee on Immunization (NACI) †. CANADA COMMUNICABLE DISEASE REPORT = RELEVE DES MALADIES TRANSMISSIBLES AU CANADA 2010; 36:1-49. [PMID: 31682656 PMCID: PMC6802438 DOI: 10.14745/ccdr.v36i00a06] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
17
|
Comparative effectiveness of medical interventions in adults versus children. J Pediatr 2010; 157:322-330.e17. [PMID: 20434730 DOI: 10.1016/j.jpeds.2010.02.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 01/15/2010] [Accepted: 02/09/2010] [Indexed: 01/03/2023]
Abstract
OBJECTIVE To estimate the comparative effectiveness of medical interventions in adults versus children. STUDY DESIGN We identified from the Cochrane Database of Systematic Reviews (Issue 1, 2007) meta-analyses with data on at least 1 adult and 1 pediatric randomized trial with binary primary efficacy outcome. For each meta-analysis, we calculated the summary odds ratio of the adult trials and the pediatric trials, respectively; the relative odds ratio (ROR) of the adult versus pediatric odds ratios per meta-analysis; and the summary ROR across all meta-analyses. ROR <1 means that the experimental intervention is more unfavorable in children than adults. RESULTS Across 128 eligible meta-analyses (1051 adult and 343 pediatric trials), the summary ROR did not show a statistically significant difference between adults and children (0.96; 95% confidence intervals, 0.86 to 1.08). However, in all meta-analyses except for 1, the individual ROR's 95% confidence intervals could not exclude a relative difference in efficacy over 20%. In two-thirds, the relative difference in observed point estimates exceeded 50%. Nine statistically significant discrepancies were identified; 4 of them were also clinically important. CONCLUSIONS Treatment effects are on average similar in adults and children, but available evidence leaves large uncertainty about their relative efficacy. Clinically important discrepancies may occur.
Collapse
|
18
|
Tuite AR, Fisman DN, Kwong JC, Greer AL. Optimal pandemic influenza vaccine allocation strategies for the Canadian population. PLoS One 2010; 5:e10520. [PMID: 20463898 PMCID: PMC2865540 DOI: 10.1371/journal.pone.0010520] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Accepted: 04/12/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The world is currently confronting the first influenza pandemic of the 21(st) century. Influenza vaccination is an effective preventive measure, but the unique epidemiological features of swine-origin influenza A (H1N1) (pH1N1) introduce uncertainty as to the best strategy for prioritization of vaccine allocation. We sought to determine optimal prioritization of vaccine distribution among different age and risk groups within the Canadian population, to minimize influenza-attributable morbidity and mortality. METHODOLOGY/PRINCIPAL FINDINGS We developed a deterministic, age-structured compartmental model of influenza transmission, with key parameter values estimated from data collected during the initial phase of the epidemic in Ontario, Canada. We examined the effect of different vaccination strategies on attack rates, hospitalizations, intensive care unit admissions, and mortality. In all scenarios, prioritization of high-risk individuals (those with underlying chronic conditions and pregnant women), regardless of age, markedly decreased the frequency of severe outcomes. When individuals with underlying medical conditions were not prioritized and an age group-based approach was used, preferential vaccination of age groups at increased risk of severe outcomes following infection generally resulted in decreased mortality compared to targeting vaccine to age groups with higher transmission, at a cost of higher population-level attack rates. All simulations were sensitive to the timing of the epidemic peak in relation to vaccine availability, with vaccination having the greatest impact when it was implemented well in advance of the epidemic peak. CONCLUSIONS/SIGNIFICANCE Our model simulations suggest that vaccine should be allocated to high-risk groups, regardless of age, followed by age groups at increased risk of severe outcomes. Vaccination may significantly reduce influenza-attributable morbidity and mortality, but the benefits are dependent on epidemic dynamics, time for program roll-out, and vaccine uptake.
Collapse
Affiliation(s)
- Ashleigh R. Tuite
- Department of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - David N. Fisman
- Department of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
| | - Jeffrey C. Kwong
- Department of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- The Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
| | - Amy L. Greer
- Modelling and Projection Section, Surveillance and Risk Assessment Division, Public Health Agency of Canada, Toronto, Ontario, Canada
| |
Collapse
|
19
|
Abstract
The world is currently confronting the first influenza pandemic of the 21st century [caused by a novel pandemic influenza A (H1N1) virus]. Earlier pandemics have been characterized by age distributions that are distinct from those observed with seasonal influenza epidemics, with higher attack rates (and correspondingly increased proportionate or relative mortality) in younger individuals. While the genesis of protection against infection in older individuals during a pandemic is uncertain, differential vulnerability to infection by age has important implications for disease dynamics and control, and for choice of optimal vaccination strategies. Age-related vulnerability to infection may explain differences between school- and community-derived estimates of the reproductive number (R) for a newly emerged pandemic strain, and may also help explain the failure of a newly emerged influenza A (H1N1) virus strain to cause a pandemic in 1977. Age-related factors may also help explain variability in attack rates, and the size and impact of influenza epidemics across jurisdictions and between populations. In Canada, such effects have been observed in the apparently increased severity of outbreaks on Indigenous peoples' reserves. The implications of these patterns for vaccine allocation necessitate targeted research to understand age-related vulnerabilities early in an influenza pandemic.
Collapse
|
20
|
Lee BY, Brown ST, Cooley PC, Zimmerman RK, Wheaton WD, Zimmer SM, Grefenstette JJ, Assi TM, Furphy TJ, Wagener DK, Burke DS. A computer simulation of employee vaccination to mitigate an influenza epidemic. Am J Prev Med 2010; 38:247-57. [PMID: 20042311 PMCID: PMC2833347 DOI: 10.1016/j.amepre.2009.11.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 11/09/2009] [Accepted: 11/12/2009] [Indexed: 11/28/2022]
Abstract
BACKGROUND Better understanding the possible effects of vaccinating employees is important and can help policymakers and businesses plan vaccine distribution and administration logistics, especially with the current H1N1 influenza vaccine in short supply. PURPOSE This article aims to determine the effects of varying vaccine coverage, compliance, administration rates, prioritization, and timing among employees during an influenza pandemic. METHODS As part of the H1N1 influenza planning efforts of the Models of Infectious Disease Agent Study network, an agent-based computer simulation model was developed for the Washington DC metropolitan region, encompassing five metropolitan statistical areas. Each simulation run involved introducing 100 infectious individuals to initiate a 1.3 reproductive-rate (R(0)) epidemic, consistent with H1N1 parameters to date. Another set of scenarios represented a R(0)=1.6 epidemic. RESULTS An unmitigated epidemic resulted in substantial productivity losses (a mean of $112.6 million for a serologic 15% attack rate and $193.8 million for a serologic 25% attack rate), even with the relatively low estimated mortality impact of H1N1. Although vaccinating Advisory Committee on Immunization Practices-defined priority groups resulted in the largest savings, vaccinating all remaining workers captured additional savings and, in fact, reduced healthcare workers' and critical infrastructure workers' chances of infection. Moreover, although employee vaccination compliance affected the epidemic, once 20% compliance was achieved, additional increases in compliance provided less incremental benefit. Even though a vast majority of the workplaces in the DC metropolitan region had fewer than 100 employees, focusing on vaccinating only those in larger firms (> or =100 employees) was just as effective in mitigating the epidemic as trying to vaccinate employees in all workplaces. CONCLUSIONS Timely vaccination of at least 20% of the large-company workforce can play an important role in epidemic mitigation.
Collapse
Affiliation(s)
- Bruce Y Lee
- University of Pittsburgh, 200 Meyran Avenue, Pittsburgh, PA 15213, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Jefferson T, Del Mar C, Dooley L, Ferroni E, Al-Ansary LA, Bawazeer GA, van Driel ML, Nair S, Foxlee R, Rivetti A. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database Syst Rev 2010:CD006207. [PMID: 20091588 DOI: 10.1002/14651858.cd006207.pub3] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Viral epidemics or pandemics of acute respiratory infections like influenza or severe acute respiratory syndrome pose a world-wide threat. Antiviral drugs and vaccinations may be insufficient to prevent catastrophe. OBJECTIVES To systematically review the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2); MEDLINE (1966 to May 2009); OLDMEDLINE (1950 to 1965); EMBASE (1990 to May 2009); and CINAHL (1982 to May 2009). SELECTION CRITERIA We scanned 2958 titles, excluded 2790 and retrieved the full papers of 168 trials, to include 59 papers of 60 studies. We included any physical interventions (isolation, quarantine, social distancing, barriers, personal protection and hygiene) to prevent transmission of respiratory viruses. We included the following study designs: randomised controlled trials (RCTs), cohorts, case controls, cross-over, before-after, and time series studies. DATA COLLECTION AND ANALYSIS We used a standardised form to assess trial eligibility. RCTs were assessed by: randomisation method; allocation generation; concealment; blinding; and follow up. Non-RCTs were assessed for the presence of potential confounders, and classified into low, medium, and high risks of bias. MAIN RESULTS The risk of bias for the four RCTs, and most cluster RCTs, was high. The observational studies were of mixed quality. Only case-control data were sufficiently homogeneous to allow meta-analysis.The highest quality cluster RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children. Additional benefit from reduced transmission from children to other household members is broadly supported in results of other study designs, where the potential for confounding is greater. Six case-control studies suggested that implementing barriers to transmission, isolation, and hygienic measures are effective at containing respiratory virus epidemics. We found limited evidence that N95 respirators were superior to simple surgical masks, but were more expensive, uncomfortable, and caused skin irritation. The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease respiratory disease remains uncertain. Global measures, such as screening at entry ports, were not properly evaluated. There was limited evidence that social distancing was effective especially if related to the risk of exposure. AUTHORS' CONCLUSIONS Many simple and probably low-cost interventions would be useful for reducing the transmission of epidemic respiratory viruses. Routine long-term implementation of some of the measures assessed might be difficult without the threat of a looming epidemic.
Collapse
Affiliation(s)
- Tom Jefferson
- Vaccines Field, The Cochrane Collaboration, Via Adige 28a, Anguillara Sabazia, Roma, Italy, 00061
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Tuite A, Fisman DN, Kwong JC, Greer A. Optimal pandemic influenza vaccine allocation strategies for the canadian population. PLOS CURRENTS 2010; 2:RRN1144. [PMID: 20069034 PMCID: PMC2804393 DOI: 10.1371/currents.rrn1144] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/07/2010] [Indexed: 11/18/2022]
Abstract
BACKGROUND The world is currently confronting the first influenza pandemic of the 21st century. Influenza vaccination is an effective preventive measure, but the unique epidemiological features of swine-origin influenza A (H1N1) (pH1N1) introduce uncertainty as to the best strategy for prioritization of vaccine allocation. We sought to determine optimal prioritization of vaccine distribution among different age and risk groups within the Canadian population, to minimize influenza-attributable morbidity and mortality. METHODOLOGY/PRINCIPAL FINDINGS We developed a deterministic, age-structured compartmental model of influenza transmission, with key parameter values estimated from data collected during the initial phase of the epidemic in Ontario, Canada. We examined the effect of different vaccination strategies on attack rates, hospitalizations, intensive care unit admissions, and mortality. In all scenarios, prioritization of high-risk groups (individuals with underlying chronic conditions and pregnant women) markedly decreased the frequency of severe outcomes. Preferential vaccination of age groups at increased risk of severe outcomes following infection resulted in decreased mortality compared to targeting vaccine to age groups with higher transmission, at a cost of higher population-level attack rates. All simulations were sensitive to the timing of the epidemic peak in relation to vaccine availability, with vaccination having the greatest impact when it was implemented well in advance of the epidemic peak. CONCLUSIONS/SIGNIFICANCE Our model simulations suggest that vaccine should be allocated to high-risk groups, regardless of age, followed by age groups at increased risk of severe outcomes. Vaccination may significantly reduce influenza-attributable morbidity and mortality, but the benefits are dependent on epidemic dynamics, time for program roll-out, and vaccine uptake.
Collapse
Affiliation(s)
- Ashleigh Tuite
- Dalla Lana School of Public Health, University of Toronto; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada and Public Health Agency of Canada
| | | | | | | |
Collapse
|
23
|
Lowen AC, Steel J, Mubareka S, Carnero E, García-Sastre A, Palese P. Blocking interhost transmission of influenza virus by vaccination in the guinea pig model. J Virol 2009; 83:2803-18. [PMID: 19153237 PMCID: PMC2655561 DOI: 10.1128/jvi.02424-08] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Accepted: 01/09/2009] [Indexed: 11/20/2022] Open
Abstract
Interventions aimed at preventing viral spread have the potential to effectively control influenza virus in all age groups, thereby reducing the burden of influenza illness. For this reason, we have examined the efficacy of vaccination in blocking the transmission of influenza viruses between guinea pigs. Three modes of immunization were compared: (i) natural infection; (ii) intramuscular administration of whole, inactivated influenza virus in 2 doses; and (iii) intranasal inoculation with live attenuated influenza virus in 2 doses. The ability of each immunization method to block the spread of a homologous (A/Panama/2007/99) H3N2 subtype and a heterologous (A/Wisconsin/67/05) H3N2 subtype influenza virus was tested. We found that previous infection through a natural route provided sterilizing immunity against both homologous and heterologous challenges; thus, no transmission to or from previously infected animals was observed. Vaccination with an inactivated influenza virus vaccine, in contrast, did not prevent guinea pigs from becoming infected upon challenge with either virus. Thus, both intranasal inoculation and exposure to an acutely infected guinea pig led to the infection of vaccinated animals. Vaccination with inactivated virus did, however, reduce viral load upon challenge and decrease the number of secondary transmission events from vaccinated animals to naïve cage mates. Vaccination with a live attenuated virus was found to be more efficacious than vaccination with inactivated virus, resulting in sterilizing immunity against homologous challenge and full protection against the transmission of the homologous and heterologous viruses to naïve contacts. In conclusion, we have shown that the guinea pig model can be used to test influenza virus vaccines and that the efficiency of transmission is a valuable readout when vaccine efficacy is evaluated.
Collapse
Affiliation(s)
- Anice C Lowen
- Department of Microbiology, Mount Sinai School of Medicine, 1 Gustave Levy Pl., New York, NY 10029-6574, USA
| | | | | | | | | | | |
Collapse
|
24
|
Routine use of influenza vaccine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009. [PMID: 19280852 DOI: 10.1007/978-0-387-79838-7_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
|
25
|
Jefferson T, Di Pietrantonj C, Debalini MG, Rivetti A, Demicheli V. Inactivated influenza vaccines: methods, policies, and politics. J Clin Epidemiol 2009; 62:677-86. [PMID: 19124222 DOI: 10.1016/j.jclinepi.2008.07.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Accepted: 07/01/2008] [Indexed: 11/24/2022]
Affiliation(s)
- T Jefferson
- Cochrane Vaccines Field, ASL AL, Alessandria, Italy.
| | | | | | | | | |
Collapse
|
26
|
|
27
|
Abstract
Since their compositions remain uncertain, universal pandemic vaccines are yet to be created. They would aim to protect globally against pandemic influenza viruses that have not yet evolved. Thus they differ from seasonal vaccines to influenza virus, which are updated annually in spring to incorporate the latest circulating viruses, and are then produced and delivered before the peak influenza season starts in late fall and winter. The efficacy of seasonal vaccines is linked to their ability to induce virus-neutralizing antibodies, which provide subtype-specific protection against influenza A viruses. If pandemic vaccines were designed to resemble current vaccines in terms of composition and mode of action, they would have to be developed, tested, and mass-produced after the onset of a pandemic, once the causative virus had been identified. The logistic problems of generating a pandemic vaccine from scratch, conducting preclinical testing, and producing billions of doses within a few months for global distribution are enormous and may well be insurmountable. Alternatively, the scientific community could step up efforts to generate a universal vaccine against influenza A viruses that provides broadly cross-reactive protection through the induction of antibodies or T cells to conserved regions of the virus.
Collapse
Affiliation(s)
| | - Walter A. Orenstein
- School of Medicine, Emory University, Clifton Road 1510, Atlanta, 30322 U.S.A
| |
Collapse
|
28
|
Jefferson T, Foxlee R, Del Mar C, Dooley L, Ferroni E, Hewak B, Prabhala A, Nair S, Rivetti A. Cochrane Review: Interventions for the interruption or reduction of the spread of respiratory viruses. EVIDENCE-BASED CHILD HEALTH : A COCHRANE REVIEW JOURNAL 2008; 3:951-1013. [PMID: 32313518 PMCID: PMC7163512 DOI: 10.1002/ebch.291] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Viral epidemics or pandemics such as of influenza or severe acute respiratory syndrome (SARS) pose a significant threat. Antiviral drugs and vaccination may not be adequate to prevent catastrophe in such an event. OBJECTIVES To systematically review the evidence of effectiveness of interventions to interrupt or reduce the spread of respiratory viruses (excluding vaccines and antiviral drugs, which have been previously reviewed). SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, issue 4); MEDLINE (1966 to November 2006); OLDMEDLINE (1950 to 1965); EMBASE (1990 to November 2006); and CINAHL (1982 to November 2006). SELECTION CRITERIA We scanned 2300 titles, excluded 2162 and retrieved the full papers of 138 trials, including 49 papers of 51 studies. The quality of three randomised controlled trials (RCTs) was poor; as were most cluster RCTs. The observational studies were of mixed quality. We were only able to meta-analyse case-control data. We searched for any interventions to prevent viral transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection and hygiene). Study design included RCTs, cohort studies, case-control studies, cross-over studies, before-after, and time series studies. DATA COLLECTION AND ANALYSIS We scanned the titles, abstracts and full text articles using a standardised form to assess eligibility. RCTs were assessed according to randomisation method, allocation generation, concealment, blinding, and follow up. Non-RCTs were assessed for the presence of potential confounders and classified as low, medium, and high risk of bias. MAIN RESULTS The highest quality cluster RCTs suggest respiratory virus spread can be prevented by hygienic measures around younger children. Additional benefit from reduced transmission from children to other household members is broadly supported in results of other study designs, where the potential for confounding is greater. The six case-control studies suggested that implementing barriers to transmission, isolation, and hygienic measures are effective at containing respiratory virus epidemics. We found limited evidence that the more uncomfortable and expensive N95 masks were superior to simple surgical masks. The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions about these measures. AUTHORS' CONCLUSIONS Many simple and probably low-cost interventions would be useful for reducing the transmission of epidemic respiratory viruses. Routine long-term implementation of some of the measures assessed might be difficult without the threat of a looming epidemic. PLAIN LANGUAGE SUMMARY Interventions to interrupt or reduce the spread of respiratory viruses Although respiratory viruses usually only cause minor disease, they can cause epidemics. Approximately 10% to 15% of people worldwide contract influenza annually, with attack rates as high as 50% during major epidemics. Global pandemic viral infections have been devastating because of their wide spread. In 2003 the severe acute respiratory syndrome (SARS) epidemic affected ˜8,000 people, killed 780, and caused an enormous social and economic crisis. A new avian influenza pandemic caused by the H5N1 strain might be more catastrophic. Single measures (particularly the use of vaccines or antiviral drugs) may be insufficient to interrupt the spread.We found 51 studies including randomised controlled trials (RCTs) and observational studies with a mixed risk of bias.Respiratory virus spread might be prevented by hygienic measures around younger children. These might also reduce transmission from children to other household members. Implementing barriers to transmission, isolation, and hygienic measures may be effective at containing respiratory virus epidemics. There was limited evidence that (more uncomfortable and expensive) N95 masks were superior to simple ones. Adding virucidals or antiseptics to normal handwashing is of uncertain benefit. There is insufficient evaluation of global measures such as screening at entry ports and social distancing.
Collapse
Affiliation(s)
- Tom Jefferson
- Vaccines Field, The Cochrane Collaboration, Roma, Italy
| | - Ruth Foxlee
- Cochrane Wounds Group, Health Sciences, University of York, York, UK
| | - Chris Del Mar
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Australia
| | - Liz Dooley
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Australia
| | - Eliana Ferroni
- Institute of Hygiene, Catholic University of The Sacred Heart, Rome, Italy
| | | | - Adi Prabhala
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Australia
| | - Sreekumaran Nair
- Department of Statistics, Manipal Academy of Higher Education, Manipal, India
| | - Alessandro Rivetti
- Servizio Regionale di Riferimento per l'Epidemiologia, SSEpi‐SeREMI ‐ Cochrane Vaccines Field, Azienda Sanitaria Locale ASL AL, Alessandria, Italy
| |
Collapse
|
29
|
Jansen AGSC, Sanders EAM, Smulders S, Hoes AW, Hak E. Adverse reactions to simultaneous influenza and pneumococcal conjugate vaccinations in children: randomized double-blind controlled trial. Pediatr Allergy Immunol 2008; 19:552-8. [PMID: 18221474 DOI: 10.1111/j.1399-3038.2007.00681.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In a randomized double-blind controlled trial, the safety was assessed of simultaneous administration of influenza and pneumococcal conjugate vaccines in children with previous physician-diagnosed respiratory tract infections. In total, 579 children aged 18-72 months were assigned to receive simultaneous intramuscular influenza and pneumococcal heptavalent conjugate vaccinations (IV + PV), influenza and placebo vaccinations (IV + plac) or control hepatitis B and placebo vaccinations (HepB + plac) in separate extremities. Local and systemic adverse events were recorded in parental diaries for 7 days after vaccination. No immediate adverse reactions were recorded. In most children local adverse reactions disappeared 2 days after vaccination. Local and systemic reactions were more prevalent (30% and 10% more) in the IV + PV group compared with the IV + plac and HepB + plac group. These results are important for designing future vaccination schedules.
Collapse
Affiliation(s)
- Angelique G S C Jansen
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
| | | | | | | | | |
Collapse
|
30
|
Madhi SA, Levine OS, Hajjeh R, Mansoor OD, Cherian T. Vaccines to prevent pneumonia and improve child survival. Bull World Health Organ 2008; 86:365-72. [PMID: 18545739 DOI: 10.2471/blt.07.044503] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Accepted: 01/24/2008] [Indexed: 10/22/2022] Open
Abstract
For more than 30 years, vaccines have played an important part in pneumonia prevention. Recent advances have created opportunities for further improving child survival through prevention of childhood pneumonia by vaccination. Maximizing routine immunization with pertussis and measles vaccines, coupled with provision of a second opportunity for measles immunization, has rapidly reduced childhood deaths in low-income countries especially in sub-Saharan Africa. Vaccines against the two leading bacterial causes of child pneumonia deaths, Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae (pneumococcus), can further improve child survival by preventing about 1,075,000 child deaths per year. Both Hib and pneumococcal conjugate vaccines have proven safety and effectiveness for prevention of radiologically confirmed pneumonia in children, including in low-income and industrializing countries. Both are recommended by WHO for inclusion in national programmes, and, at sharply tiered prices, these vaccines generally meet international criteria of cost-effectiveness for low-income countries. Vaccines only target selected pneumonia pathogens and are less than 100% effective, so they must be complemented by curative care and other preventative strategies. As part of a comprehensive child survival package, the particular advantages of vaccines include the ability to reach a high proportion of all children, including those who are difficult to reach with curative health services, and the ability to rapidly scale up coverage with new vaccines. In this review, we discuss advances made in optimizing the use of established vaccines and the potential issues related to newer bacterial conjugate vaccines in reducing childhood pneumonia morbidity and mortality.
Collapse
Affiliation(s)
- Shabir A Madhi
- Department of Science and Technology, National Research Foundation, Vaccine Preventable Diseases, Chris Hani Baragwanth Hospital, University of the Witwatersrand, Bertsham, South Africa.
| | | | | | | | | |
Collapse
|
31
|
Jansen AGSC, Sanders EAM, Wallinga J, Groen EJ, van Loon AM, Hoes AW, Hak E. Rate-difference method proved satisfactory in estimating the influenza burden in primary care visits. J Clin Epidemiol 2008; 61:803-12. [PMID: 18495428 DOI: 10.1016/j.jclinepi.2007.08.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 08/24/2007] [Accepted: 08/31/2007] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To compare different methods to estimate the disease burden of influenza, using influenza and respiratory syncytial virus-(RSV) associated primary care data as an example. STUDY DESIGN AND SETTING In a retrospective study in the Netherlands over 1997-2003, primary care attended respiratory episodes and national viral surveillance data were used to compare the rate-difference method to other, more complex methods. RESULTS The influenza-associated excess estimated by the different methods varied. The estimates provided by the rate-difference model lay well within this range. According to the rate-difference method, influenza-associated primary care consultations were present for all ages, including low-risk adults. The highest influenza-associated burden was demonstrated for children below the age of 5 years. The RSV-associated primary care burden was highest in the youngest age category and well above that associated with influenza. Significant RSV-associated excess was also recorded among adults, particularly in high-risk adults and the elderly. CONCLUSION The straightforward rate-difference model seemed satisfactory to estimate the influenza-associated burden. Significant influenza-associated excess was demonstrated among persons not yet recommended for influenza vaccination in The Netherlands. The RSV-associated burden was highest for the youngest children, but also significant for adults.
Collapse
Affiliation(s)
- Angelique G S C Jansen
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, the Netherlands.
| | | | | | | | | | | | | |
Collapse
|
32
|
D’Onise K, Raupach JCA. The burden of influenza in healthy children in South Australia. Med J Aust 2008; 188:510-3. [DOI: 10.5694/j.1326-5377.2008.tb01763.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Accepted: 12/18/2007] [Indexed: 11/17/2022]
|
33
|
Jefferson T, Rivetti A, Harnden A, Di Pietrantonj C, Demicheli V. Vaccines for preventing influenza in healthy children. Cochrane Database Syst Rev 2008:CD004879. [PMID: 18425905 DOI: 10.1002/14651858.cd004879.pub3] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The consequences of influenza in children and adults are mainly absenteeism from school and work. However, the risk of complications is greatest in children and people over 65 years old. OBJECTIVES To appraise all comparative studies evaluating the effects of influenza vaccines in healthy children; assess vaccine efficacy (prevention of confirmed influenza) and effectiveness (prevention of influenza-like illness) and document adverse events associated with influenza vaccines. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, issue 3); OLD MEDLINE (1950 to 1965); MEDLINE (1966 to September 2007); EMBASE (1974 to September 2007); Biological Abstracts (1969 to September 2007); and Science Citation Index (1974 to September 2007). SELECTION CRITERIA Randomised controlled trials (RCTs), cohort and case-control studies of any influenza vaccine in healthy children under 16 years of age. DATA COLLECTION AND ANALYSIS Two review authors independently assessed trial quality and extracted data. MAIN RESULTS Fifty-one studies with 294,159 observations were included. Sixteen RCTs and 18 cohort studies were included in the analysis of vaccine efficacy and effectiveness. From RCTs, live vaccines showed an efficacy of 82% (95% confidence interval (CI) 71% to 89%) and an effectiveness of 33% (95% CI 28% to 38%) in children older than two compared with placebo or no intervention. Inactivated vaccines had a lower efficacy of 59% (95% CI 41% to 71%) than live vaccines but similar effectiveness: 36% (95% CI 24% to 46%). In children under two, the efficacy of inactivated vaccine was similar to placebo. Variability in study design and presentation of data was such that a meta-analysis of safety outcome data was not feasible. Extensive evidence of reporting bias of safety outcomes from trials of live attenuated vaccines impeded meaningful analysis. AUTHORS' CONCLUSIONS Influenza vaccines are efficacious in children older than two but little evidence is available for children under two. There was a marked difference between vaccine efficacy and effectiveness. No safety comparisons could be carried out, emphasizing the need for standardisation of methods and presentation of vaccine safety data in future studies. It was surprising to find only one study of inactivated vaccine in children under two years, given current recommendations to vaccinate healthy children from six months old in the USA and Canada. If immunisation in children is to be recommended as a public health policy, large-scale studies assessing important outcomes and directly comparing vaccine types are urgently required.
Collapse
Affiliation(s)
- Tom Jefferson
- Vaccines Field, Cochrane Collaboration, Via Adige 28a, Anguillara Sabazia, Roma, Italy, 00061
| | | | | | | | | |
Collapse
|
34
|
Ciofi degli Atti ML, Merler S, Rizzo C, Ajelli M, Massari M, Manfredi P, Furlanello C, Scalia Tomba G, Iannelli M. Mitigation measures for pandemic influenza in Italy: an individual based model considering different scenarios. PLoS One 2008; 3:e1790. [PMID: 18335060 PMCID: PMC2258437 DOI: 10.1371/journal.pone.0001790] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Accepted: 02/01/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Individual-based models can provide the most reliable estimates of the spread of infectious diseases. In the present study, we evaluated the diffusion of pandemic influenza in Italy and the impact of various control measures, coupling a global SEIR model for importation of cases with an individual based model (IBM) describing the Italian epidemic. METHODOLOGY/PRINCIPAL FINDINGS We co-located the Italian population (57 million inhabitants) to households, schools and workplaces and we assigned travel destinations to match the 2001 census data. We considered different R(0 )values (1.4; 1.7; 2), evaluating the impact of control measures (vaccination, antiviral prophylaxis -AVP-, international air travel restrictions and increased social distancing). The administration of two vaccine doses was considered, assuming that first dose would be administered 1-6 months after the first world case, and different values for vaccine effectiveness (VE). With no interventions, importation would occur 37-77 days after the first world case. Air travel restrictions would delay the importation of the pandemic by 7-37 days. With an R(0 )of 1.4 or 1.7, the use of combined measures would reduce clinical attack rates (AR) from 21-31% to 0.3-4%. Assuming an R(0) of 2, the AR would decrease from 38% to 8%, yet only if vaccination were started within 2 months of the first world case, in combination with a 90% reduction in international air traffic, closure of schools/workplaces for 4 weeks and AVP of household and school/work close contacts of clinical cases. Varying VE would not substantially affect the results. CONCLUSIONS This IBM, which is based on country-specific demographic data, could be suitable for the real-time evaluation of measures to be undertaken in the event of the emergence of a new pandemic influenza virus. All preventive measures considered should be implemented to mitigate the pandemic.
Collapse
|
35
|
Jones S, Jones R. Influenza: prevention, prophylaxis and treatment. S Afr Fam Pract (2004) 2008. [DOI: 10.1080/20786204.2008.10873691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
36
|
Jefferson T, Foxlee R, Del Mar C, Dooley L, Ferroni E, Hewak B, Prabhala A, Nair S, Rivetti A. Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review. BMJ 2008; 336:77-80. [PMID: 18042961 PMCID: PMC2190272 DOI: 10.1136/bmj.39393.510347.be] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To systematically review evidence for the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. DATA EXTRACTION Search strategy of the Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without language restriction, for any intervention to prevent transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection, and hygiene). Study designs were randomised trials, cohort studies, case-control studies, and controlled before and after studies. DATA SYNTHESIS Of 2300 titles scanned 138 full papers were retrieved, including 49 papers of 51 studies. Study quality was poor for the three randomised controlled trials and most of the cluster randomised controlled trials; the observational studies were of mixed quality. Heterogeneity precluded meta-analysis of most data except that from six case-control studies. The highest quality cluster randomised trials suggest that the spread of respiratory viruses into the community can be prevented by intervening with hygienic measures aimed at younger children. Meta-analysis of six case-control studies suggests that physical measures are highly effective in preventing the spread of SARS: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat=4, 95% confidence interval 3.65 to 5.52); wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03); wearing N95 masks (0.09, 0.03 to 0.30; NNT=3, 2.37 to 4.06); wearing gloves (0.43, 0.29 to 0.65; NNT=5, 4.15 to 15.41); wearing gowns (0.23, 0.14 to 0.37; NNT=5, 3.37 to 7.12); and handwashing, masks, gloves, and gowns combined (0.09, 0.02 to 0.35; NNT=3, 2.66 to 4.97). The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease the spread of respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions being drawn. CONCLUSION Routine long term implementation of some physical measures to interrupt or reduce the spread of respiratory viruses might be difficult but many simple and low cost interventions could be useful in reducing the spread.
Collapse
|
37
|
Ros Aranal I, Navarra Vicente B, Lavilla Fernández M, De Juan Martín F, Bouthelier Moreno M, Omeñaca Teres M, Ciria Calavia L. Características clínicas y actuaciones en los niños ingresados por gripe en cuatro períodos epidémicos gripales (2002-2006). An Pediatr (Barc) 2008; 68:24-9. [DOI: 10.1157/13114467] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
38
|
Zündorf I. [Influenza vaccination for medical personnel]. PHARMAZIE IN UNSERER ZEIT 2008; 37:52-53. [PMID: 18081044 DOI: 10.1002/pauz.200790131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
|
39
|
Jefferson T, Foxlee R, Del Mar C, Dooley L, Ferroni E, Hewak B, Prabhala A, Nair S, Rivetti A. Interventions for the interruption or reduction of the spread of respiratory viruses. Cochrane Database Syst Rev 2007:CD006207. [PMID: 17943895 DOI: 10.1002/14651858.cd006207.pub2] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Viral epidemics or pandemics such as of influenza or severe acute respiratory syndrome (SARS) pose a significant threat. Antiviral drugs and vaccination may not be adequate to prevent catastrophe in such an event. OBJECTIVES To systematically review the evidence of effectiveness of interventions to interrupt or reduce the spread of respiratory viruses (excluding vaccines and antiviral drugs, which have been previously reviewed). SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 4); MEDLINE (1966 to November 2006); OLDMEDLINE (1950 to 1965); EMBASE (1990 to November 2006); and CINAHL (1982 to November 2006). SELECTION CRITERIA We scanned 2300 titles, excluded 2162 and retrieved the full papers of 138 trials, including 49 papers of 51 studies. The quality of three randomised controlled trials (RCTs) was poor; as were most cluster RCTs. The observational studies were of mixed quality. We were only able to meta-analyse case-control data. We searched for any interventions to prevent viral transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection and hygiene). Study design included RCTs, cohort studies, case-control studies, cross-over studies, before-after, and time series studies. DATA COLLECTION AND ANALYSIS We scanned the titles, abstracts and full text articles using a standardised form to assess eligibility. RCTs were assessed according to randomisation method, allocation generation, concealment, blinding, and follow up. Non-RCTs were assessed for the presence of potential confounders and classified as low, medium, and high risk of bias. MAIN RESULTS The highest quality cluster RCTs suggest respiratory virus spread can be prevented by hygienic measures around younger children. Additional benefit from reduced transmission from children to other household members is broadly supported in results of other study designs, where the potential for confounding is greater. The six case-control studies suggested that implementing barriers to transmission, isolation, and hygienic measures are effective at containing respiratory virus epidemics. We found limited evidence that the more uncomfortable and expensive N95 masks were superior to simple surgical masks. The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions about these measures. AUTHORS' CONCLUSIONS Many simple and probably low-cost interventions would be useful for reducing the transmission of epidemic respiratory viruses. Routine long-term implementation of some of the measures assessed might be difficult without the threat of a looming epidemic.
Collapse
|
40
|
Simonsen L, Taylor RJ, Viboud C, Miller MA, Jackson LA. Mortality benefits of influenza vaccination in elderly people: an ongoing controversy. THE LANCET. INFECTIOUS DISEASES 2007; 7:658-66. [PMID: 17897608 DOI: 10.1016/s1473-3099(07)70236-0] [Citation(s) in RCA: 376] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Influenza vaccination policy in most high-income countries attempts to reduce the mortality burden of influenza by targeting people aged at least 65 years for vaccination. However, the effectiveness of this strategy is under debate. Although placebo-controlled randomised trials show influenza vaccine is effective in younger adults, few trials have included elderly people, and especially those aged at least 70 years, the age-group that accounts for three-quarters of all influenza-related deaths. Recent excess mortality studies were unable to confirm a decline in influenza-related mortality since 1980, even as vaccination coverage increased from 15% to 65%. Paradoxically, whereas those studies attribute about 5% of all winter deaths to influenza, many cohort studies report a 50% reduction in the total risk of death in winter--a benefit ten times greater than the estimated influenza mortality burden. New studies, however, have shown substantial unadjusted selection bias in previous cohort studies. We propose an analytical framework for detecting such residual bias. We conclude that frailty selection bias and use of non-specific endpoints such as all-cause mortality have led cohort studies to greatly exaggerate vaccine benefits. The remaining evidence base is currently insufficient to indicate the magnitude of the mortality benefit, if any, that elderly people derive from the vaccination programme.
Collapse
Affiliation(s)
- Lone Simonsen
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | | | | | | | | |
Collapse
|
41
|
Chowell G, Miller MA, Viboud C. Seasonal influenza in the United States, France, and Australia: transmission and prospects for control. Epidemiol Infect 2007; 136:852-64. [PMID: 17634159 PMCID: PMC2680121 DOI: 10.1017/s0950268807009144] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Recurrent epidemics of influenza are observed seasonally around the world with considerable health and economic consequences. A key quantity for the control of infectious diseases is the reproduction number, which measures the transmissibility of a pathogen and determines the magnitude of public health interventions necessary to control epidemics. Here we applied a simple epidemic model to weekly indicators of influenza mortality to estimate the reproduction numbers of seasonal influenza epidemics spanning three decades in the United States, France, and Australia. We found similar distributions of reproduction number estimates in the three countries, with mean value 1.3 and important year-to-year variability (range 0.9-2.1). Estimates derived from two different mortality indicators (pneumonia and influenza excess deaths and influenza-specific deaths) were in close agreement for the United States (correlation=0.61, P60%) in healthy individuals who respond well to vaccine, in addition to periodic re-vaccination due to evolving viral antigens and waning population immunity.
Collapse
Affiliation(s)
- G Chowell
- Theoretical Division (MS B284), Los Alamos National Laboratory, Los Alamos, NM 87544, USA.
| | | | | |
Collapse
|
42
|
Corbeel L. Should healthy children be vaccinated against influenza? Comments about this query. Eur J Pediatr 2007; 166:629-31. [PMID: 17008996 DOI: 10.1007/s00431-006-0285-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Accepted: 06/20/2006] [Indexed: 10/24/2022]
|
43
|
Abstract
Each year enormous effort goes into producing influenza vaccines for that specific year and delivering them to appropriate sections of the population. Is this effort justified?
Collapse
Affiliation(s)
- Tom Jefferson
- Cochrane Vaccines Field, Anguillara Sabazia, Roma 00061, Italy.
| |
Collapse
|