Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children

A chimeric haemagglutinin-based universal influenza virus vaccine boosts human cellular immune responses directed towards the conserved haemagglutinin stalk domain and the viral nucleoprotein

BACKGROUND

The development of a universal influenza virus vaccine, to protect against both seasonal and pandemic influenza A viruses, is a long-standing public health goal. The conserved stalk domain of haemagglutinin (HA) is a promising vaccine target. However, the stalk is immunosubdominant. As such, innovative approaches are required to elicit robust immunity against this domain. In a previously reported observer-blind, randomised placebo-controlled phase I trial (NCT03300050), immunisation regimens using chimeric HA (cHA)-based immunogens formulated as inactivated influenza vaccines (IIV) -/+ AS03 adjuvant, or live attenuated influenza vaccines (LAIV), elicited durable HA stalk-specific antibodies with broad reactivity. In this study, we sought to determine if these vaccines could also boost T cell responses against HA stalk, and nucleoprotein (NP).

METHODS

We measured interferon-γ (IFN-γ) responses by Enzyme-Linked ImmunoSpot (ELISpot) assay at baseline, seven days post-prime, pre-boost and seven days post-boost following heterologous prime:boost regimens of LAIV and/or adjuvanted/unadjuvanted IIV-cHA vaccines.

FINDINGS

Our findings demonstrate that immunisation with adjuvanted cHA-based IIVs boost HA stalk-specific and NP-specific T cell responses in humans. To date, it has been unclear if HA stalk-specific T cells can be boosted in humans by HA-stalk focused universal vaccines. Therefore, our study will provide valuable insights for the design of future studies to determine the precise role of HA stalk-specific T cells in broad protection.

INTERPRETATION

Considering that cHA-based vaccines also elicit stalk-specific antibodies, these data support the further clinical advancement of cHA-based universal influenza vaccine candidates.

FUNDING

This study was funded in part by the Bill and Melinda Gates Foundation (BMGF).

Unmasking the potential of secretory IgA and its pivotal role in protection from respiratory viruses

Mucosal immunity has regained its spotlight amidst the ongoing Coronavirus disease 19 (COVID-19) pandemic, with numerous studies highlighting the crucial role of mucosal secretory IgA (SIgA) in protection against Severe acute respiratory syndrome coronavirus-2 or SARS-CoV-2 infections. The observed limitations in the efficacy of currently authorized COVID-19 vaccines in inducing effective mucosal immune responses remind us of the limitations of systemic vaccination in promoting protective mucosal immunity. This resurgence of interest has motivated the development of vaccine platforms capable of enhancing mucosal responses, specifically the SIgA response, and the development of IgA-based therapeutics. Recognizing viral respiratory infections as a global threat, we would like to comprehensively review the existing knowledge on mucosal immunity, with a particular emphasis on SIgA, in the context of SARS-CoV-2, influenza, and Respiratory Syncytial Virus (RSV) infections. This review aims to describe the structural and functional specificities of SIgA, along with its nuanced role in combating influenza, RSV, and SARS-CoV-2 infections. Subsequent sections further elaborate promising vaccine strategies, including mucosal vaccines against Influenza, RSV, and SARS-CoV-2 respiratory viruses, currently undergoing preclinical and clinical development. Additionally, we address the challenges associated with mucosal vaccine development, concluding with a discussion on IgA-based therapeutics as a promising platform for the treatment of viral respiratory infections. This comprehensive review not only synthesizes current insights into mucosal immunity but also identifies critical knowledge gaps, strengthening the way for further advancements in our current understanding and approaches to combat respiratory viral threats.

Evaluation of Oseltamivir Used to Prevent Hospitalization in Outpatients With Influenza: A Systematic Review and Meta-Analysis

Importance

Despite widespread use, summary evidence from prior meta-analyses has contradictory conclusions regarding whether oseltamivir decreases the risk of hospitalization when given to outpatients. Several large investigator-initiated randomized clinical trials have not yet been meta-analyzed.

Objective

To assess the efficacy and safety of oseltamivir in preventing hospitalization among influenza-infected adult and adolescent outpatients.

Data Sources

PubMed, Ovid MEDLINE, Embase, Europe PubMed Central, Web of Science, Cochrane Central, ClinicalTrials.gov, and WHO International Clinical Trials Registry were searched from inception to January 4, 2022.

Study Selection

Included studies were randomized clinical trials comparing oseltamivir vs placebo or nonactive controls in outpatients with confirmed influenza infection.

Data Extraction and Synthesis

In this systematic review and meta-analysis, Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were followed. Two independent reviewers (R.H. and É.B.C.) extracted data and assessed risk of bias using the Cochrane Risk of Bias Tool 2.0. Each effect size was pooled using a restricted maximum likelihood random effects model. The quality of evidence was graded using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework.

Main Outcomes and Measures

Hospitalization was pooled as risk ratio (RR) and risk difference (RD) estimates with 95% CIs.

Results

Of 2352 studies identified, 15 were included. The intention-to-treat infected (ITTi) population was comprised of 6166 individuals with 54.7% prescribed oseltamivir. Across study populations, 53.9% (5610 of 10 471) were female and the mean age was 45.3 (14.5) years. Overall, oseltamivir was not associated with reduced risk of hospitalization within the ITTi population (RR, 0.79; 95% CI, 0.48 to 1.29; RD, -0.17%; 95% CI, -0.23% to 0.48%). Oseltamivir was also not associated with reduced hospitalization in older populations (mean age ≥65 years: RR, 1.01; 95% CI, 0.21 to 4.90) or in patients considered at greater risk of hospitalization (RR, 0.65; 0.33 to 1.28). Within the safety population, oseltamivir was associated with increased nausea (RR, 1.43; 95% CI, 1.13 to 1.82) and vomiting (RR, 1.83; 95% CI, 1.28 to 2.63) but not serious adverse events (RR, 0.71; 95% CI, 0.46 to1.08).

Conclusions and Relevance

In this systematic review and meta-analysis among influenza-infected outpatients, oseltamivir was not associated with a reduced risk of hospitalization but was associated with increased gastrointestinal adverse events. To justify continued use for this purpose, an adequately powered trial in a suitably high-risk population is justified.

The Impact of Point-of-Care Testing for Influenza on Antimicrobial Stewardship (PIAMS) in UK Primary Care: Protocol for a Mixed Methods Study

BACKGROUND

Molecular point-of-care testing (POCT) used in primary care can inform whether a patient presenting with an acute respiratory infection has influenza. A confirmed clinical diagnosis, particularly early in the disease, could inform better antimicrobial stewardship. Social distancing and lockdowns during the COVID-19 pandemic have disturbed previous patterns of influenza infections in 2021. However, data from samples taken in the last quarter of 2022 suggest that influenza represents 36% of sentinel network positive virology, compared with 24% for respiratory syncytial virus. Problems with integration into the clinical workflow is a known barrier to incorporating technology into routine care.

OBJECTIVE

This study aims to report the impact of POCT for influenza on antimicrobial prescribing in primary care. We will additionally describe severe outcomes of infection (hospitalization and mortality) and how POCT is integrated into primary care workflows.

METHODS

The impact of POCT for influenza on antimicrobial stewardship (PIAMS) in UK primary care is an observational study being conducted between December 2022 and May 2023 and involving 10 practices that contribute data to the English sentinel network. Up to 1000 people who present to participating practices with respiratory symptoms will be swabbed and tested with a rapid molecular POCT analyzer in the practice. Antimicrobial prescribing and other study outcomes will be collected by linking information from the POCT analyzer with data from the patient's computerized medical record. We will collect data on how POCT is incorporated into practice using data flow diagrams, unified modeling language use case diagrams, and Business Process Modeling Notation.

RESULTS

We will present the crude and adjusted odds of antimicrobial prescribing (all antibiotics and antivirals) given a POCT diagnosis of influenza, stratifying by whether individuals have a respiratory or other relevant diagnosis (eg, bronchiectasis). We will also present the rates of hospital referrals and deaths related to influenza infection in PIAMS study practices compared with a set of matched practices in the sentinel network and the rest of the network. We will describe any difference in implementation models in terms of staff involved and workflow.

CONCLUSIONS

This study will generate data on the impact of POCT testing for influenza in primary care as well as help to inform about the feasibility of incorporating POCT into primary care workflows. It will inform the design of future larger studies about the effectiveness and cost-effectiveness of POCT to improve antimicrobial stewardship and any impact on severe outcomes.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/46938.

Modern approaches at the management of children with community-acquired pneumonia

Experts of The Union of Pediatricians of Russia have developed current clinical guidelines for management of children with community-acquired pneumonia, which were approved by the Scientific and Practice Council of Ministry of Public Health of the Russian Federation in January 2022. Particular attention is paid to the etiological structure, modern classification, diagnostic tests and flagship approaches to antibacterial therapy of community-acquired pneumonia in children based on the principles of evidentiary medicine. 

Efficacy and safety of baloxavir marboxil versus neuraminidase inhibitors in the treatment of influenza virus infection in high-risk and uncomplicated patients - a Bayesian network meta-analysis

OBJECTIVES

Previous network meta-analysis (NMA) demonstrated advantageous or similar efficacy of baloxavir marboxil (baloxavir) over neuraminidase inhibitors in otherwise healthy (OwH) influenza patients. This analysis assessed the efficacy and safety of baloxavir in the subgroup of high-risk (HR) patients and in the population of uncomplicated influenza consisting of OwH and HR patients with influenza.

METHODS

A systematic literature review (SLR) was performed in Medline, Embase, CENTRAL and ICHUSHI up to August 8th, 2018. A Bayesian NMA was conducted to compare baloxavir with oseltamivir, zanamivir, laninamivir and peramivir in HR patients and all uncomplicated patients.

RESULTS

Based on the SLR, a total of 32 studies were identified as pertinent for the analysis, including 7 studies on HR patients, 13 trials on OwH patients and 14 studies on OwH + HR population. NMA of 10 trials assessing HR patients demonstrated comparable time to alleviation of symptoms for all treatments. Mean decline in virus titer from baseline at 24 h after treatment was significantly greater for baloxavir compared with oseltamivir and peramivir. The risks of total complications and drug-related adverse events were comparable between baloxavir and zanamivir, oseltamivir and laninamivir. These findings were highly consistent with results of the NMA using pooled evidence on the uncomplicated population of OwH and HR patients.

Conclusions: Baloxavir was significantly more effective than placebo regarding all outcomes except for the risk of pneumonia. Besides, baloxavir was associated with similar clinical efficacy and safety, and superior antiviral activity compared to other antivirals in HR patients, as well as in the entire population of uncomplicated patients with influenza.

[A network meta-analysis of the efficacy and safety of baloxavir marboxil versus neuraminidase inhibitors for the treatment of influenza in otherwise healthy patients]

AIM

Baloxavir marboxil (baloxavir) is the first cap-dependent endonuclease inhibitor being studied for the treatment of influenza in single oral dosing regimen. This network meta-analysis (NMA) evaluated the efficacy and safety of baloxavir compared to other antivirals for influenza in otherwise healthy patients.

METHODS

A systematic literature review was performed on 14 November 2016 in Medline, Embase, CENTRAL, and ICHUSHI to identify randomized controlled trials assessing antivirals for influenza. A NMA including 22 trials was performed to compare the efficacy and safety of baloxavir with other antivirals.

RESULTS

The time to alleviation of all symptoms was significantly shorter for baloxavir compared to zanamivir (difference in median time 19.96 h; 95% CrI [3.23, 39.07]). The time to cessation of viral shedding was significantly shorter for baloxavir than zanamivir and oseltamivir (47.00 h; 95% CrI [28.18, 73.86] and 56.03 h [33.74, 87.86], respectively). The mean decline in virus titer from baseline to 24 h was significantly greater for baloxavir than for the other drugs. Other differences in efficacy outcomes were not significant. No significant differences were found between baloxavir and the other antivirals for safety, except total drug-related adverse events where baloxavir demonstrated a decrease compared to oseltamivir and laninamivir.

CONCLUSION

The NMA suggests that baloxavir demonstrated better or similar efficacy results compared to other antivirals with a comparable safety profile. Baloxavir led to a significant decrease in viral titer versus zanamivir, oseltamivir and peramivir and decreased viral shedding versus zanamivir and oseltamivir.

Outcome of Patients Admitted to Intensive Care Units due to Influenza-Related Severe Acute Respiratory Illness in 2017-2018 Flu Season: A Multicenter Study from Turkey

BACKGROUND

Influenza can cause severe acute respiratory illness (SARI), which occurs as local outbreaks or seasonal epidemics with high intensive care unit (ICU) admission and mortality rates. Mortality is mainly due to SARI.

OBJECTIVE

The aim of this study was to evaluate the outcome of patients admitted to ICU due to influenza-related SARI in 2017-2018 flu season in Turkey.

METHODS

A retrospective multicenter study was conducted in 13 ICUs with a total of 216 beds from 6 cities in Turkey. All adult patients (over 18 years) admitted to the ICUs in 2017-2018 flu season (between September 1, 2017, and April 30, 2018) because of SARI and with a positive nasopharyngeal swab for influenza were included in the study.

RESULTS

A total of 123 cases were included in the study. The mean age of patients was 64.5 ± 17.5 years, and 66 (53.7%) patients were older than 65 years. The ICU mortality was 33.9%, and hospital mortality was 35.6%. Invasive mechanical ventilation (IMV), acute kidney injury (AKI), hematologic malignancy, and >65 years of age were the factors affecting mortality in influenza.

CONCLUSION

SARI due to influenza carries a high mortality rate, and IMV, AKI, presence of hematologic malignancy, and older age are independent risk factors for mortality.

Neuraminidase Inhibitors and Hospital Length of Stay: A Meta-analysis of Individual Participant Data to Determine Treatment Effectiveness Among Patients Hospitalized With Nonfatal 2009 Pandemic Influenza A(H1N1) Virus Infection

Background

The effect of neuraminidase inhibitor (NAI) treatment on length of stay (LoS) in patients hospitalized with influenza is unclear.

Methods

We conducted a one-stage individual participant data (IPD) meta-analysis exploring the association between NAI treatment and LoS in patients hospitalized with 2009 influenza A(H1N1) virus (A[H1N1]pdm09) infection. Using mixed-effects negative binomial regression and adjusting for the propensity to receive NAI, antibiotic, and corticosteroid treatment, we calculated incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Patients with a LoS of <1 day and those who died while hospitalized were excluded.

Results

We analyzed data on 18 309 patients from 70 clinical centers. After adjustment, NAI treatment initiated at hospitalization was associated with a 19% reduction in the LoS among patients with clinically suspected or laboratory-confirmed influenza A(H1N1)pdm09 infection (IRR, 0.81; 95% CI, .78–.85), compared with later or no initiation of NAI treatment. Similar statistically significant associations were seen in all clinical subgroups. NAI treatment (at any time), compared with no NAI treatment, and NAI treatment initiated <2 days after symptom onset, compared with later or no initiation of NAI treatment, showed mixed patterns of association with the LoS.

Conclusions

When patients hospitalized with influenza are treated with NAIs, treatment initiated on admission, regardless of time since symptom onset, is associated with a reduced LoS, compared with later or no initiation of treatment.

Influenza vaccination in the COVID-19 era

Influenza spreads globally annually with significant paediatric and adult attack rates and considerable morbidity, mortality and the exacerbation of extant chronic disease. In the northern and southern hemispheres, outbreaks occur mainly in the respective winter seasons. Influenza vaccination is available but only partially effective. In the absence of a vaccine, in winter, novel coronavirus COVID-19 will also circulate in parallel with seasonal influenza. Thus far it appears that with the current strains of these two viruses, the clinical outcome of co-infection is not significantly worse than infection with COVID-19 alone. However, several strains of influenza circulate, including strains still to come. Similarly, COVID-19 has several strains, with probably more to come. This paper discusses these issues and estimates ideal minimum influenza vaccination coverage based on an estimated influenza Basic Reproduction Number (R0) of 0.9-2.1 so as to obtain herd immunity or approach it. There is a strong argument for attempting near universal population coverage with the annual influenza vaccine leading up to next winter.

Microbiome in Chronic Obstructive Pulmonary Disease: Role of Natural Products Against Microbial Pathogens

The "microbiome" is the operative term to refer to a collection of all taxa constituting microbial communities, such as bacteria, archaea, fungi and protists (originally microbiota). The microbiome consists of the indigenous microbial communities and of the host environment that they inhabit. Actually, it has been shown that there is a close relationship between the microbiome and human health and disease condition. Although, initially, the lung was considered sterile, actually, the existence of a healthy lung microbiome is usually accepted. Lung microbiome changes are reported in Chronic Obstructive Pulmonary Disease (COPD) and in its exacerbation. Viral and bacterial infections of the respiratory system are a major cause of COPD exacerbations (AECOPD) leading to increased local and systemic inflammation. Detection rates of virus in AECOPD are variable between 25-62% according to the detection method. The study of human airway and lung disease virome is quite recent and still very limited. The purpose of this review is to summarize recent findings on the lung microbiome composition with a special emphasis on virome in COPD and in AECOPD. Some drugs of natural origins active against resistant bacteria and virus are described.

Antiviral treatment for outpatient use during an influenza pandemic: a decision tree model of outcomes averted and cost-effectiveness

Background

Many countries have acquired antiviral stockpiles for pandemic influenza mitigation and a significant part of the stockpile may be focussed towards community-based treatment.

Methods

We developed a spreadsheet-based, decision tree model to assess outcomes averted and cost-effectiveness of antiviral treatment for outpatient use from the perspective of the healthcare payer in the UK. We defined five pandemic scenarios—one based on the 2009 A(H1N1) pandemic and four hypothetical scenarios varying in measures of transmissibility and severity.

Results

Community-based antiviral treatment was estimated to avert 14–23% of hospitalizations in an overall population of 62.28 million. Higher proportions of averted outcomes were seen in patients with high-risk conditions, when compared to non-high-risk patients. We found that antiviral treatment was cost-saving across pandemic scenarios for high-risk population groups, and cost-saving for the overall population in higher severity influenza pandemics. Antiviral effectiveness had the greatest influence on both the number of hospitalizations averted and on cost-effectiveness.

Conclusions

This analysis shows that across pandemic scenarios, antiviral treatment can be cost-saving for population groups at high risk of influenza-related complications.

Utility of Rapid Influenza Molecular Testing in an Outpatient Hemodialysis Unit: A Prospective Cohort Study

Background:

Early initiation of antiviral therapy for individuals at risk for severe influenza infection is important for improving patient outcomes. Current guidelines recommend empiric antiviral therapy for patients with end-stage kidney disease presenting with suspected influenza infection. Rapid molecular influenza assays may reduce diagnostic uncertainty and improve patient outcomes by providing faster diagnostics compared to traditional batched polymerase chain reaction (PCR) testing.

Objective:

To determine the utility of implementing a rapid influenza PCR assay compared to the standard of care in a hemodialysis unit.

Design:

This is a prospective cohort study.

Setting:

A hospital-based dialysis unit in a tertiary care hospital.

Patients:

Adult patients with end-stage kidney disease on intermittent hemodialysis.

Measurements:

Patient characteristics, influenza PCR swab results, antibiotic prescriptions, antiviral prescriptions, emergency room visits and hospitalizations.

Methods:

From November 1, 2017 to March 31, 2018, we assigned samples collected from a single center, hemodialysis unit to be processed using a rapid influenza PCR (cobas® Influenza A/B & respiratory syncytial virus assay) or the standard of care (in-house developed multiplex PCR). Samples were assigned to the rapid PCR if the patient received dialysis treatment in the morning dialysis shift, while the remainder were processed as per standard of care. Study outcomes included the time from collection to result of nasopharyngeal swab, prescription of influenza antiviral therapy, time to receiving prescription, and the need for emergency department visit or hospitalization within 2 weeks of presentation.

Results:

During the study period, 44 patients were assessed (14 with the rapid PCR and 30 with the standard of care assay). Compared to conventional testing, the time to result was shorter using rapid PCR compared to conventional testing (2.3 vs 22.6 hours, P < .0001). Individuals who were tested using the rapid PCR had a tendency to shorter time to receiving antiviral prescriptions (0.7 days vs 2.1 days, P = .11), and fewer emergency department visits (7.1% vs 30%, P = .13) but no difference in hospitalizations (14.3% vs 30%, P = .46) within 2 weeks of testing.

Limitations:

This is a single center non-randomized study with a relatively small sample size. Patients who were tested using the standard of care assay experienced a delay in the prescription of antiviral therapy which deviates from recommended clinical practice.

Conclusions:

Rapid influenza molecular testing in the hemodialysis unit was associated with a shorter time to a reportable result and with a tendency to reduced time to prescription of antiviral therapy. Rapid molecular testing should be compared with standard of care (empiric therapy) in terms of economic costs, adverse events, and influenza-related outcomes.

Opportunities for selective reporting of harms in randomized clinical trials: Selection criteria for non-systematic adverse events

BACKGROUND

Adverse events (AEs) in clinical trials may be reported in multiple sources. Different methods for reporting adverse events across trials or across sources for a single trial may produce inconsistent information about the adverse events associated with interventions.

METHODS

We compared the methods authors use to decide which AEs to include in a particular source (i.e., "selection criteria"), including the number of different types of AEs reported (i.e., rather than the number of events). We compared sources (e.g., journal articles, clinical study reports (CSRs)) of trials for two drug-indications-gabapentin for neuropathic pain and quetiapine for bipolar depression. Electronic searches were completed in 2015. We identified selection criteria and assessed how criteria affected AE reporting.

RESULTS

We identified 21 gabapentin and 7 quetiapine trials. We found 6 gabapentin CSRs and 2 quetiapine CSRs, all written by drug manufacturers. All CSRs reported all AEs without applying selection criteria; by comparison, no other source reported all AEs, and 15/68 (22%) gabapentin sources and 19/48 (40%) quetiapine sources reported using selection criteria. Selection criteria greatly affected the number of AEs reported. For example, 67/316 (21%) AEs in one quetiapine trial met the criterion "occurring in ≥2% of participants in any treatment group," while only 5/316 (2%) AEs met the criterion "occurring in ≥10% of quetiapine-treated patients and twice as frequent in the quetiapine group as the placebo group."

CONCLUSIONS

Selection criteria for reporting AEs vary across trials and across sources for individual trials. If investigators do not pre-specify selection criteria, they might "cherry-pick" AEs based on results. Even if investigators pre-specify selection criteria, selective reporting will produce biased meta-analyses and clinical practice guidelines. Data about all AEs identified in clinical trials should be publicly available; however, sharing data will not solve all the problems identified in this study.

MF59-adjuvanted seasonal trivalent inactivated influenza vaccine: Safety and immunogenicity in young children at risk of influenza complications

OBJECTIVE

To assess the safety and immunogenicity of the MF59-adjuvanted seasonal trivalent inactivated influenza vaccine (aIIV3; Fluad) in children aged 6 months through 5 years who are at risk of influenza complications.

METHODS

A retrospective analysis was performed to examine unsolicited adverse events (AEs) in an integrated dataset from six randomized clinical studies that compared aIIV3 with non-adjuvanted inactivated influenza vaccines (IIV3). The integrated safety set comprised 10 784 children, of whom 373 (3%) were at risk of influenza complications.

RESULTS

The at-risk safety population comprised 373 children aged 6 months through 5 years: 179 received aIIV3 and 194 received non-adjuvanted IIV3 (128 subjects received a licensed IIV3). The most important risk factors were respiratory system illnesses (62-70%) and infectious and parasitic diseases (33-39%). During the treatment period, unsolicited AEs occurred in 54% of at-risk children and 55% of healthy children who received aIIV3; of those receiving licensed IIV3, 59% of at-risk and 62% of healthy subjects reported an unsolicited AE. The most common AEs were infections, including upper respiratory tract infection. Serious AEs (SAEs) were reported in <10% of at-risk subjects, and no vaccine-related SAEs were observed. In the immunogenicity subset (involving 103 participants from one study), geometric mean titers (GMTs) were approximately 2- to 3-fold higher with aIIV3 than with IIV3 for all three homologous strains (A/H1N1, A/H3N2, and B). Seroconversion rates were high for both aIIV3 (79-96%) and IIV3 (83-89%).

CONCLUSIONS

In young children at risk of influenza complications, aIIV3 was well-tolerated and had a safety profile that was generally similar to that of non-adjuvanted IIV3. Similar to the not-at-risk population, the immune response in at-risk subjects receiving aIIV3 was increased over those receiving IIV3, suggesting aIIV3 is a valuable option in young children at risk of influenza complications.

Neuropsychiatric events in an adult patient with influenza a (H3N2) treated with oseltamivir (Tamiflu): a case report

Background

Total four influenza pandemics have happened since twentieth century, and currently influenza is in the seasonal epidemic around the world, with a sharp increase in its incidence each year. As an effective treatment of influenza infection, the use of oseltamivir is climbing globally. However, there have been reports of neuropsychiatric events associated with the drug, mainly in young patients and males. To our knowledge, this is the first reported case of oseltamivir-associated neuropsychiatric events occurring in an patient over 50-year-old.

Case presentation

Here we present the case of a 57-year-old Chinese female with H3N2 influenza infection who developed abnormal psychiatric symptoms after administration of high doses of oseltamivir. The patient recovered completely within the cessation of oseltamivir.

Conclusions

We hope that our case report will lead clinicians to be mindful about oseltamivir’s potential neuropsychiatric side effects, and to pay special attention to each patient’s mental state, both in children and adults.

Incidence of hospitalisation for severe complications of influenza virus infection in Japanese patients between 2012 and 2016: a cross-sectional study using routinely collected administrative data

OBJECTIVE

To calculate the incidence of hospitalisation due to acute respiratory failure, pneumonia, acute respiratory distress syndrome (ARDS), febrile seizures and encephalitis/encephalopathy among influenza-positive patients in Japan, where point-of-care tests are routinely used to diagnose influenza.

DESIGN

A cross-sectional study using routinely collected data.

SETTING

Japanese clinics and hospitals between 2012 and 2016.

PARTICIPANTS

Japanese patients aged 0-74 years diagnosed with influenza by a rapid test in employment-related health insurance records.

PRIMARY OUTCOME MEASURES

Incidence of hospitalisation per 100 000 influenza-positive episodes.

RESULTS

We included over 16 million influenza-positive episodes, 1.0% of whom were hospitalised. Of these, 3361 were acute respiratory failure, 27 253 pneumonia, 18 ARDS, 2603 febrile seizure and 159 encephalitis/encephalopathy. The percentage of hospitalisations by age was 2.96% of patients aged 0-1 years, 0.77% aged 2-5, 0.51% aged 6-12, 0.78% aged 13-18, 1.36% aged 19-44, 1.19% aged 45-64, and 2.21% aged 65-74. The incidence of hospitalisations from these five complications combined was highest in influenza-positive patients aged 0-1 years (943 per 100 000) compared with 307 in those aged 2-5 years and 271 in those aged 65-74 years. For pneumonia, the incidence was highest for influenza-positive patients aged 0-5 years and 65 years or more. There were statistically significant decreasing trends over the years in the incidence of all-cause hospitalisations, pneumonia and febrile seizures.

CONCLUSIONS

Japanese administrative data revealed that 1.0% of influenza-positive patients aged under 75 years were hospitalised. Male patients had a higher incidence of pulmonary complications and febrile seizures. Children aged 0-5 years and adults aged 65-74 years were at high risk of being admitted to hospital for pneumonia.

Use of Whole-Genome Sequencing in the Investigation of a Nosocomial Influenza Virus Outbreak

Traditional epidemiological investigation of nosocomial transmission of influenza involves the identification of patients who have the same influenza virus type and who have overlapped in time and place. This method may misidentify transmission where it has not occurred or miss transmission when it has. We used influenza virus whole-genome sequencing (WGS) to investigate an outbreak of influenza A virus infection in a hematology/oncology ward and identified 2 separate introductions, one of which resulted in 5 additional infections and 79 bed-days lost. Results from WGS are becoming rapidly available and may supplement traditional infection control procedures in the investigation and management of nosocomial outbreaks.

Live attenuated influenza vaccine for children

For many years, the UK seasonal influenza vaccination programme has been offered to people at higher risk from the complications of influenza infection, including those aged over 65 years and anyone aged over 6 months who is in a clinical risk group.¹ In 2012, the Joint Committee on Vaccination and Immunisation (JCVI) recommended extending seasonal influenza vaccination to children aged 2-16 years who are not in a clinical risk group.² In contrast to the vaccination programme for adults, which uses an injectable inactivated influenza vaccine, children are being offered a live attenuated influenza vaccine (LAIV) that is administered intranasally.² Here, we consider the evidence for the use of the intranasal influenza vaccine for children who are not in a clinical risk group.

Treating Influenza Infection, From Now and Into the Future

Influenza viruses (IVs) are a continual threat to global health. The high mutation rate of the IV genome makes this virus incredibly successful, genetic drift allows for annual epidemics which result in thousands of deaths and millions of hospitalizations. Moreover, the emergence of new strains through genetic shift (e.g., swine-origin influenza A) can cause devastating global outbreaks of infection. Neuraminidase inhibitors (NAIs) are currently used to treat IV infection and act directly on viral proteins to halt IV spread. However, effectivity is limited late in infection and drug resistance can develop. New therapies which target highly conserved features of IV such as antibodies to the stem region of hemagglutinin or the IV RNA polymerase inhibitor: Favipiravir are currently in clinical trials. Compared to NAIs, these treatments have a higher tolerance for resistance and a longer therapeutic window and therefore, may prove more effective. However, clinical and experimental evidence has demonstrated that it is not just viral spread, but also the host inflammatory response and damage to the lung epithelium which dictate the outcome of IV infection. Therapeutic regimens for IV infection should therefore also regulate the host inflammatory response and protect epithelial cells from unnecessary cell death. Anti-inflammatory drugs such as etanercept, statins or cyclooxygenase enzyme 2 inhibitors may temper IV induced inflammation, demonstrating the possibility of repurposing these drugs as single or adjunct therapies for IV infection. IV binds to sialic acid receptors on the host cell surface to initiate infection and productive IV replication is primarily restricted to airway epithelial cells. Accordingly, targeting therapies to the epithelium will directly inhibit IV spread while minimizing off target consequences, such as over activation of immune cells. The neuraminidase mimic Fludase cleaves sialic acid receptors from the epithelium to inhibit IV entry to cells. While type III interferons activate an antiviral gene program in epithelial cells with minimal perturbation to the IV specific immune response. This review discusses the above-mentioned candidate anti-IV therapeutics and others at the preclinical and clinical trial stage.

Infectious illness prevention and control methods and their effectiveness in non-health workplaces: an integrated literature review

BACKGROUND

Infectious illness in the workplace places a substantial cost burden on employers due to productivity losses from employee absenteeism and presenteeism.

AIM

Given the clear impacts of infectious illness on workplaces, this review aimed to investigate the international literature on the effectiveness and cost-benefit of the strategies non-healthcare workplaces use to prevent and control infectious illnesses in these workplaces.

METHODS

MEDLINE, CINAHL Plus with Fulltext and Business Source Complete were searched concurrently using EBSCO Host 1995-2016.

FINDINGS

Infection prevention and control strategies to reduce workplace infectious illness and absenteeism evaluated in the literature include influenza vaccination programs, use of alcohol-based hand sanitiser and paid sick days. While the reported studies have various methodological flaws, there is good evidence of the effectiveness of influenza vaccination in preventing workplace infectious illness and absences and moderate evidence to support hand hygiene programs.

DISCUSSION

Some studies used more than one intervention concurrently, making it difficult to determine the relative benefit of each individual strategy. Workplace strategies to prevent and control infectious illness transmission may reduce costs and productivity losses experienced by businesses and organisations related to infectious illness absenteeism and presenteeism.

A qualitative analysis of the beliefs of Japanese anti-influenza vaccination website authors

Background

Influenza vaccine coverage among the Japanese population is less than optimal. Anti-vaccination sentiment exists worldwide, and Japan is no exception. Anti-influenza vaccination activists argue on the internet that influenza vaccine has little or no efficacy and a high risk of side effects, and they warn that people should forgo vaccination. We conducted a qualitative analysis to explore beliefs underlying the messages of anti-influenza vaccination websites, by focusing on the perceived value these beliefs provide to those who hold them.

Methods

We conducted online searches in January 2017 using two major Japanese search engines (Google Japan and Yahoo! Japan). Targeted websites were classified as “pro”, “anti”, or “neutral” depending on their claims. We applied a dual analytic approach—inductive thematic analysis and deductive interpretative analysis—to textual data of the anti websites.

Results

Of the 113 anti websites, we identified two themes that correspond to beliefs: it is necessary to 1) protect others against risks and exploitation related to influenza vaccination, and 2) educate others about hidden truths and self-determination. Authors of anti websites ascribed two values (people's “safety” and one's own “self-esteem”) to their beliefs.

Discussion

Website authors may engage in anti-vaccination activities because they want to feel they are virtuous, saving people from harm caused by vaccination, and to boost their self-esteem, thinking “I am enlightening uninformed people.” The anti-vaccination beliefs of website authors were considered to be strong. In promoting vaccination, it would be better not to target outright vaccine refusers, such as the authors of anti-vaccination websites; it is preferable to target vaccine-hesitant people who are more amenable to changing their attitudes toward vaccination. We discuss possible means of promoting vaccination in that target population.

Evolution of Therapeutic Antibodies, Influenza Virus Biology, Influenza, and Influenza Immunotherapy

This narrative review article summarizes past and current technologies for generating antibodies for passive immunization/immunotherapy. Contemporary DNA and protein technologies have facilitated the development of engineered therapeutic monoclonal antibodies in a variety of formats according to the required effector functions. Chimeric, humanized, and human monoclonal antibodies to antigenic/epitopic myriads with less immunogenicity than animal-derived antibodies in human recipients can be produced in vitro. Immunotherapy with ready-to-use antibodies has gained wide acceptance as a powerful treatment against both infectious and noninfectious diseases. Influenza, a highly contagious disease, precipitates annual epidemics and occasional pandemics, resulting in high health and economic burden worldwide. Currently available drugs are becoming less and less effective against this rapidly mutating virus. Alternative treatment strategies are needed, particularly for individuals at high risk for severe morbidity. In a setting where vaccines are not yet protective or available, human antibodies that are broadly effective against various influenza subtypes could be highly efficacious in lowering morbidity and mortality and controlling unprecedented epidemic/pandemic. Prototypes of human single-chain antibodies to several conserved proteins of influenza virus with no Fc portion (hence, no ADE effect in recipients) are available. These antibodies have high potential as a novel, safe, and effective anti-influenza agent.

Estimating the annual attack rate of seasonal influenza among unvaccinated individuals: A systematic review and meta-analysis

INTRODUCTION

Seasonal influenza affects millions of people globally each year, causing significant morbidity and mortality. However, there remains substantial uncertainty about the attack rate (incidence) of influenza, particularly in unvaccinated individuals.

METHODS

We undertook a systematic review of vaccine randomised controlled trials (RCTs) that reported on laboratory-confirmed seasonal influenza in the placebo arm. We calculated the influenza attack rate from included studies as the number of laboratory-confirmed positive seasonal influenza cases in the placebo arm divided by the total number of subjects in this arm. A random effects meta-analysis was conducted to estimate the influenza attack rate among unvaccinated individuals (both symptomatic only as well as symptomatic and asymptomatic combined).

RESULTS

We included 32 RCTs that had a total of 13,329 participants. The pooled estimates for symptomatic influenza were 12.7% (95%CI 8.5%, 18.6%) for children (<18 years), 4.4% (95%CI 3.0%, 6.3%) for adults, and 7.2% (95%CI 4.3%, 12.0%) for older people (65 years and above). The pooled estimates for symptomatic and asymptomatic influenza combined for all influenza were 22.5% (95%CI 9.0%, 46.0%) for children and 10.7% (95%CI 4.5%, 23.2%) for adults. Only one study was identified for symptomatic and asymptomatic combined in older people which had a rate of 8.8% (95%CI 7.0%, 10.8%). There was substantial heterogeneity between studies.

CONCLUSION

Overall, we found that approximately 1 in 5 unvaccinated children and 1 in 10 unvaccinated adults were estimated to be infected by seasonal influenza annually, with rates of symptomatic influenza roughly half of these estimates. Our findings help to establish the background risk of seasonal influenza infection in unvaccinated individuals.

Cost-Effectiveness Analysis of Pneumococcal and Influenza Vaccines Administered to Children Less Than 5 Years of Age in a Low-Income District of Bogota, Colombia

BACKGROUND

The Colombian health authorities introduced the pneumococcal conjugated vaccine and the seasonal influenza vaccine into the national immunization schedule for children in 2009 and 2007, respectively. Despite this, the health authorities continue to be concerned about the high economic and disease burden among children from low-income households caused by these vaccine-preventable diseases.

OBJECTIVES

1) To evaluate the potential health outcomes of four vaccination strategies for subsidized children younger than 5 years in a low-income district in Colombia from a public, direct medical health care perspective. 2) To perform univariate, multivariate, and probabilistic sensitivity analysis to evaluate the robustness of these results.

METHODS

We built a Markov deterministic cohort model to evaluate five consecutive cohorts across four alternative situations: 1) no vaccination; 2) vaccination with the 10-valent pneumococcal conjugate vaccine (PCV10 vaccine); 3) vaccination with the trivalent inactivated vaccine (TIV) annually; and 4) combined vaccination with PCV10 vaccine and TIV.

RESULTS

The introduction of PCV10 vaccine and TIV and their combined use in particular would be highly cost-effective in comparison to no vaccination. For the combined vaccination with PCV10 vaccine and TIV, the incremental cost-effectiveness ratio would be $1,280 per disability-adjusted life-year (DALY) averted, the total incremental cost of the vaccination program would be $776,800, and it would avert four deaths and 332 DALYs for the five cohorts.

CONCLUSIONS

The introduction of PCV10 vaccine and TIV would be highly cost-effective from a public, direct medical health care perspective. Despite these results, we have not observed decreases in severity or hospitalizations. Our findings highlight the need for further studies of the immunization campaign indicators and socioeconomic indicators for this low-income community.

Prevention of vaccine-matched and mismatched influenza in children aged 6-35 months: a multinational randomised trial across five influenza seasons

BACKGROUND

Despite the importance of vaccinating children younger than 5 years, few studies evaluating vaccine prevention of influenza have been reported in this age group. We evaluated efficacy of an inactivated quadrivalent influenza vaccine (IIV4) in children aged 6-35 months.

METHODS

In this phase 3, observer-blinded, multinational trial, healthy children from 13 countries in Europe, Central America, and Asia were recruited in five independent cohorts, each in a different influenza season. Participants were randomly assigned (1:1) to either IIV4 (15 μg haemagglutinin antigen per strain per 0·5 mL dose; a single dose on day 0 for vaccine-primed children, and two doses, on days 0 and 28, for vaccine-unprimed children) or to one or two doses of a non-influenza control vaccine. Primary endpoints were moderate-to-severe influenza or all influenza (irrespective of disease severity) confirmed by RT-PCR on nasal swabs. Cultured isolates were further characterised as antigenically matched or mismatched to vaccine strains. Efficacy was assessed in the per-protocol cohort and total vaccinated cohort (time-to-event analysis), and safety was assessed in the total vaccinated cohort.

FINDINGS

Between Oct 1, 2011, and Dec 31, 2014, 12 018 children were recruited into the total vaccinated cohort (6006 children in the IIV4 group and 6012 children in the control group). 356 (6%) children in the IIV4 group and 693 (12%) children in the control group had at least one case of RT-PCR-confirmed influenza. Of these 1049 influenza strains, 138 (13%) were A/H1N1, 529 (50%) were A/H3N2, 69 (7%) were B/Victoria, and 316 (30%) were B/Yamagata. Overall, 539 (64%) of 848 antigenically characterised isolates were vaccine-mismatched (16 [15%] of 105 for A/H1N1; 368 [97%] of 378 for A/H3N2; 54 [86%] of 63 for B/Victoria; 101 [33%] of 302 for B/Yamagata). Vaccine efficacy was 63% (97·5% CI 52-72) against moderate-to-severe influenza and 50% (42-57) against all influenza in the per-protocol cohort, and 64% (53-73) against moderate-to-severe influenza and 50% (42-57) against all influenza in the total vaccinated cohort. There were no clinically meaningful safety differences between IIV4 and control.

INTERPRETATION

IIV4 prevented influenza A and B in children aged 6-35 months despite high levels of vaccine mismatch. Vaccine efficacy was highest against moderate-to-severe disease, which is the most clinically important endpoint associated with greatest burden.

FUNDING

GlaxoSmithKline Biologicals SA.

Neuraminidase inhibitors for influenza: a systematic review and meta-analysis of regulatory and mortality data

BACKGROUND

Neuraminidase inhibitors (NIs) are stockpiled and recommended by public health agencies for treating and preventing seasonal and pandemic influenza. They are used clinically worldwide.

OBJECTIVES

To (1) describe the potential benefits and harms of NIs for influenza in all age groups by reviewing all clinical study reports (CSRs) of published and unpublished randomised, placebo-controlled trials and regulatory comments; and (2) determine the effect of oseltamivir (Tamiflu(®), Roche) treatment on mortality in patients with 2009A/H1N1 influenza.

METHODS

We searched trial registries, electronic databases and corresponded with regulators and sponsors to identify randomised trials of NIs. We requested full CSRs and accessed regulators' comments. We included only those trials for which we had CSRs. To examine the effects of oseltamivir on 2009A/H1N1 influenza mortality, we requested individual patient data (IPD) from corresponding authors of all included observational studies.

RESULTS

Effect of oseltamivir and zanamivir (Relenza®, GlaxoSmithKline) in the prevention and treatment of influenza: Oseltamivir reduced the time to first alleviation of symptoms in adults by 16.8 hours [95% confidence interval (CI) 8.4 to 25.1 hours]. Zanamivir reduced the time to first alleviation of symptoms in adults by 0.60 days (95% CI 0.39 to 0.81 days). Oseltamivir reduced unverified pneumonia in adult treatment [risk difference (RD) 1.00%, 95% CI 0.22% to 1.49%]; similar findings were observed with zanamivir prophylaxis in adults (RD 0.32%, 95% CI 0.09% to 0.41%). Oseltamivir treatment of adults increased the risk of nausea (RD 3.66%, 95% CI 0.90% to 7.39%) and vomiting (RD 4.56%, 95% CI 2.39% to 7.58%). In the treatment of children, oseltamivir induced vomiting (RD 5.34%, 95% CI 1.75% to 10.29%). Both oseltamivir and zanamivir prophylaxis reduced the risk of symptomatic influenza in individuals (oseltamivir RD 3.05%, 95% CI 1.83% to 3.88%; zanamivir RD 1.98%, 95% CI 0.98% to 2.54%) and in households (oseltamivir RD 13.6%, 95% CI 9.52% to 15.47%; zanamivir RD 14.84%, 95% CI 12.18% to 16.55%). Oseltamivir increased psychiatric adverse events in the combined on- and off-treatment periods (RD 1.06%, 95% CI 0.07% to 2.76%) and the risk of headaches while on treatment (RD 3.15%, 95% CI 0.88% to 5.78%). Effect of oseltamivir on mortality in patients with 2009A/H1N1 influenza: Analysis of summary data of 30 studies as well as IPD of four studies showed evidence of time-dependent bias. After adjusting for time-dependent bias and potential confounding variables, competing risks analysis of the IPD showed insufficient evidence that oseltamivir reduced the risk of mortality (hazard ratio 1.03, 95% CI 0.64 to 1.65).

CONCLUSIONS

Oseltamivir and zanamivir cause small reductions in the time to first alleviation of influenza symptoms in adults. The use of oseltamivir increases the risk of nausea, vomiting, psychiatric events in adults and vomiting in children. Oseltamivir has no protective effect on mortality among patients with 2009A/H1N1 influenza. Prophylaxis with either NI may reduce symptomatic influenza in individuals and in households. The balance between benefits and harms should be considered when making decisions about use of NIs for either prophylaxis or treatment of influenza.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002245.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Preparation, characterization and immunological evaluation of alginate nanoparticles loaded with whole inactivated influenza virus: Dry powder formulation for nasal immunization in rabbits

It has become important to explore more efficient and feasible influenza vaccines, since epidemics of influenza virus cause hundreds of thousands of deaths all around the world. Improving immunogenicity of parentral influenza vaccines has given rise to mucosal delivery routes. In this study, alginate nanoparticles (NPs) were efficiently synthetized by ionic gelation method and influenza virus and CpG ODN or Quillaja Saponin (QS) adjuvants were actively incorporated into alginate NPs. The prepared particles were evaluated for both humoral and cellular immune responses in rabbits' nostrils. The vaccination started with a prime dose and followed by three boosters (two intranasal (IN) on days 45 and 60 and the last dose, intramuscular (IM) on day 75). HAI titer had increased in all the samples; although, only in the group received WV + CPG suspension reached to the protective HAI titer. All the immunized rabbits elicited significantly high sIgA levels on day 75, compared to the negative and the IM groups. At the end of the study, IN administration of CpG ODN adjuvant with virus antigen induced higher IgG level than the groups vaccinated with alginate NPs with or without CpG ODN (P < 0.001). As for the cellular immunity, CpG ODN was capable of inducing significant levels of IL-4 and TNF-α, either through inoculation along with the virus suspension or as incorporated in alginate NPs. According to the obtained data, CpG ODN adjuvant showed higher immunogenic potential as part of a vaccine delivery system than QS. Moreover, applying alginate polymer as a nasal delivery system carrier was not deemed immunogenic against influenza whole virus.

Examining publication bias-a simulation-based evaluation of statistical tests on publication bias

Background

Publication bias is a form of scientific misconduct. It threatens the validity of research results and the credibility of science. Although several tests on publication bias exist, no in-depth evaluations are available that examine which test performs best for different research settings.

Methods

Four tests on publication bias, Egger’s test (FAT), p-uniform, the test of excess significance (TES), as well as the caliper test, were evaluated in a Monte Carlo simulation. Two different types of publication bias and its degree (0%, 50%, 100%) were simulated. The type of publication bias was defined either as file-drawer, meaning the repeated analysis of new datasets, or p-hacking, meaning the inclusion of covariates in order to obtain a significant result. In addition, the underlying effect (β = 0, 0.5, 1, 1.5), effect heterogeneity, the number of observations in the simulated primary studies (N = 100, 500), and the number of observations for the publication bias tests (K = 100, 1,000) were varied.

Results

All tests evaluated were able to identify publication bias both in the file-drawer and p-hacking condition. The false positive rates were, with the exception of the 15%- and 20%-caliper test, unbiased. The FAT had the largest statistical power in the file-drawer conditions, whereas under p-hacking the TES was, except under effect heterogeneity, slightly better. The CTs were, however, inferior to the other tests under effect homogeneity and had a decent statistical power only in conditions with 1,000 primary studies.

Discussion

The FAT is recommended as a test for publication bias in standard meta-analyses with no or only small effect heterogeneity. If two-sided publication bias is suspected as well as under p-hacking the TES is the first alternative to the FAT. The 5%-caliper test is recommended under conditions of effect heterogeneity and a large number of primary studies, which may be found if publication bias is examined in a discipline-wide setting when primary studies cover different research problems.

Potential Consequences of Not Using Live Attenuated Influenza Vaccine

INTRODUCTION

Decreased live attenuated influenza vaccine (LAIV) effectiveness in the U.S. prompted the Advisory Committee on Immunization Practices in August 2016 to recommend against this vaccine's use. However, overall influenza uptake increases when LAIV is available and, unlike the U.S., LAIV has retained its effectiveness in other countries. These opposing countercurrents create a dilemma.

METHODS

To examine the potential consequences of the decision to not recommend LAIV, which may result in decreased influenza vaccination coverage in the U.S. population, a Markov decision analysis model was used to examine influenza vaccination options in U.S. children aged 2-8 years. Data were compiled and analyzed in 2016.

RESULTS

Using recently observed low LAIV effectiveness values, fewer influenza cases will occur if LAIV is not used compared with having LAIV as a vaccine option. However, having the option to use LAIV may be favored if LAIV effectiveness returns to prior levels or if the absence of vaccine choice substantially decreases overall vaccine uptake.

CONCLUSIONS

Continued surveillance of LAIV effectiveness and influenza vaccine uptake is warranted, given their importance in influenza vaccination policy decisions.

Possible explanations for why some countries were harder hit by the pandemic influenza virus in 2009 - a global mortality impact modeling study

BACKGROUND

A global pandemic mortality study found prominent regional mortality variations in 2009 for Influenza A(H1N1)pdm09. Our study attempts to identify factors that explain why the pandemic mortality burden was high in some countries and low in others.

METHODS

As a starting point, we identified possible risk factors worth investigating for Influenza A(H1N1)pdm09 mortality through a targeted literature search. We then used a modeling procedure (data simulations and regression models) to identify factors that could explain differences in respiratory mortality due to Influenza A(H1N1)pdm09. We ran sixteen models to produce robust results and draw conclusions. In order to assess the role of each factor in explaining differences in excess pandemic mortality, we calculated the reduction in between country variance, which can be viewed as an effect-size for each factor.

RESULTS

The literature search identified 124 publications and 48 possible risk factors, of which we were able to identify 27 factors with appropriate global datasets. The modelling procedure indicated that age structure (explaining 40% of the mean between country variance), latitude (8%), influenza A and B viruses circulating during the pandemic (3-8%), influenza A and B viruses circulating during the preceding influenza season (2-6%), air pollution (pm10; 4%) and the prevalence of other infections (HIV and TB) (4-6%) were factors that explained differences in mortality around the world. Healthcare expenditure, levels of obesity, the distribution of antivirals, and air travel did not explain global pandemic mortality differences.

CONCLUSIONS

Our study found that countries with a large proportion of young persons had higher pandemic mortality rates in 2009. The co-circulation of influenza viruses during the pandemic and the circulation of influenza viruses during the preceding season were also associated with pandemic mortality rates. We found that real time assessments of 2009 pandemic mortality risk factors (e.g. obesity) probably led to a number of false positive findings.

Urgent challenges in implementing live attenuated influenza vaccine

Conflicting reports have emerged about the effectiveness of the live attenuated influenza vaccine. The live attenuated influenza vaccine appears to protect particularly poorly against currently circulating H1N1 viruses that are derived from the 2009 pandemic H1N1 viruses. During the 2015-16 influenza season, when pandemic H1N1 was the predominant virus, studies from the USA reported a complete lack of effectiveness of the live vaccine in children. This finding led to a crucial decision in the USA to recommend that the live vaccine not be used in 2016-17 and to switch to the inactivated influenza vaccine. Other countries, including the UK, Canada, and Finland, however, have continued to recommend the use of the live vaccine. This policy divergence and uncertainty has far reaching implications for the entire global community, given the importance of the production capabilities of the live attenuated influenza vaccine for pandemic preparedness. In this Personal View, we discuss possible explanations for the observed reduced effectiveness of the live attenuated influenza vaccine and highlight the underpinning scientific questions. Further research to understand the reasons for these observations is essential to enable informed public health policy and commercial decisions about vaccine production and development in coming years.

Cetylpyridinium Chloride (CPC) Exhibits Potent, Rapid Activity Against Influenza Viruses in vitro and in vivo

Background:

There is a continued need for strategies to prevent influenza. While cetylpyridinium chloride (CPC), a broad-spectrum antimicrobial agent, has an extensive antimicrobial spectrum, its ability to affect respiratory viruses has not been studied in detail.

Objectives:

Here, we evaluate the ability of CPC to disrupt influenza viruses in vitro and in vivo.

Methods:

The virucidal activity of CPC was evaluated against susceptible and oseltamivir- resistant strains of influenza viruses. The effective virucidal concentration (EC) of CPC was determined using a hemagglutination assay and tissue culture infective dose assay. The effect of CPC on viral envelope morphology and ultrastructure was evaluated using transmission electron microscopy (TEM). The ability of influenza virus to develop resistance was evaluated after multiple passaging in sub-inhibitory concentrations of CPC. Finally, the efficacy of CPC in formulation to prevent and treat influenza infection was evaluated using the PR8 murine influenza model.

Results:

The virucidal effect of CPC occurred within 10 minutes, with mean EC₅₀ and EC_2log ranging between 5 to 20 μg/mL, for most strains of influenza tested regardless of type and resistance to oseltamivir. Examinations using TEM showed that CPC disrupted the integrity of the viral envelope and its morphology. Influenza viruses demonstrated no resistance to CPC despite prolonged exposure. Treated mice exhibited significantly increased survival and maintained body weight compared to untreated mice.

Conclusions:

The antimicrobial agent CPC possesses virucidal activity against susceptible and resistant strains of influenza virus by targeting and disrupting the viral envelope. Substantial virucidal activity is seen even at very low concentrations of CPC without development of resistance. Moreover, CPC in formulation reduces influenza-associated mortality and morbidity in vivo.

Case-control vaccine effectiveness studies: Data collection, analysis and reporting results

The case-control methodology is frequently used to evaluate vaccine effectiveness post-licensure. The results of such studies provide important insight into the level of protection afforded by vaccines in a 'real world' context, and are commonly used to guide vaccine policy decisions. However, the potential for bias and confounding are important limitations to this method, and the results of a poorly conducted or incorrectly interpreted case-control study can mislead policies. In 2012, a group of experts met to review recent experience with case-control studies evaluating vaccine effectiveness; we summarize the recommendations of that group regarding best practices for data collection, analysis, and presentation of the results of case-control vaccine effectiveness studies. Vaccination status is the primary exposure of interest, but can be challenging to assess accurately and with minimal bias. Investigators should understand factors associated with vaccination as well as the availability of documented vaccination status in the study context; case-control studies may not be a valid method for evaluating vaccine effectiveness in settings where many children lack a documented immunization history. To avoid bias, it is essential to use the same methods and effort gathering vaccination data from cases and controls. Variables that may confound the association between illness and vaccination are also important to capture as completely as possible, and where relevant, adjust for in the analysis according to the analytic plan. In presenting results from case-control vaccine effectiveness studies, investigators should describe enrollment among eligible cases and controls as well as the proportion with no documented vaccine history. Emphasis should be placed on confidence intervals, rather than point estimates, of vaccine effectiveness. Case-control studies are a useful approach for evaluating vaccine effectiveness; however careful attention must be paid to the collection, analysis and presentation of the data in order to best inform evidence-based vaccine policies.

Grey literature in systematic reviews: a cross-sectional study of the contribution of non-English reports, unpublished studies and dissertations to the results of meta-analyses in child-relevant reviews

Background

Systematic reviews (SRs) are an important source of information about healthcare interventions. A key component of a well-conducted SR is a comprehensive literature search. There is limited evidence on the contribution of non-English reports, unpublished studies, and dissertations and their impact on results of meta-analyses.

Methods

Our sample included SRs from three Cochrane Review Groups: Acute Respiratory Infections (ARI), Infectious Diseases (ID), Developmental Psychosocial and Learning Problems (DPLP) (n = 129). Outcomes included: 1) proportion of reviews that searched for and included each study type; 2) proportion of relevant studies represented by each study type; and 3) impact on results and conclusions of the primary meta-analysis for each study type.

Results

Most SRs searched for non-English studies; however, these were included in only 12% of reviews and represented less than 5% of included studies. There was a change in results in only four reviews (total sample = 129); in two cases the change did not have an impact on the statistical or clinical significance of results. Most SRs searched for unpublished studies but the majority did not include these (only 6%) and they represented 2% of included studies. In most cases the impact of including unpublished studies was small; a substantial impact was observed in one case that relied solely on unpublished data. Few reviews in ARI (9%) and ID (3%) searched for dissertations compared to 65% in DPLP. Overall, dissertations were included in only nine SRs and represented less than 2% of included studies. In the majority of cases the change in results was negligible or small; in the case where a large change was noted, the estimate was more conservative without dissertations.

Conclusions

The majority of SRs searched for non-English and unpublished studies; however, these represented a small proportion of included studies and rarely impacted the results and conclusions of the review. Inclusion of these study types may have an impact in situations where there are few relevant studies, or where there are questionable vested interests in the published literature. We found substantial variation in whether SRs searched for dissertations; in most reviews that included dissertations, these had little impact on results.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-017-0347-z) contains supplementary material, which is available to authorized users.

Incidence of respiratory viral infections and associated factors among children attending a public kindergarten in Taipei City

BACKGROUND

Kindergarteners frequently encounter various infectious diseases, so surveillance of viral infectious diseases would provide information for their health promotion.

METHODS

We enrolled kindergarten attendees, age 2-5 years, during the academic years of 2006 and 2007 in a Taipei City kindergarten. Daily monitoring of illness and regular biweekly physical examinations were undertaken. Multiple infections were defined as one child having two or more laboratory-confirmed viral infections with different viruses or different serotypes during one academic year.

RESULTS

The overall laboratory-confirmed incidence rate of respiratory viral infection was 239 per 100 person-years in the 2006 academic year and 136 per 100 person-years in the 2007 academic year. The attack rate for seasonal influenza was 17% in the 2006 academic year and 27% in the 2007 academic year. Boys and children with allergies had significantly higher risks to get multiple viral infections [odds ratio (OR) 1.81, 95% confidence interval (CI) 1.20-2.75; OR 1.56, 95% CI 1.00-2.39, respectively]. Boys also tended to get enterovirus infections (OR 1.56, 95% CI 1.02-2.38) while children with allergies tended to acquire adenovirus infections (OR 1.71, 95% CI 1.12-2.66).

CONCLUSION

Boys and children with allergies were more susceptible to multiple viral infections, so they should be more cautious about viral infections.

Randomized, double-blind, placebo-controlled clinical trial to assess the safety and effectiveness of a novel dual-action oral topical formulation against upper respiratory infections

Background

Current prevention options for upper respiratory infections (URIs) are not optimal. We conducted a randomized, double-blinded, placebo-controlled pilot clinical trial to evaluate the safety and efficacy of ARMS-I™ (currently marketed as Halo™) in the prevention of URIs.

Methods

ARMS-I is patented novel formulation for the prevention and treatment of influenza, comprising a broad-spectrum antimicrobial agent (cetylpyridinium chloride, CPC) and components (glycerin and xanthan gum) that form a barrier on the host mucosa, thus preventing viral contact and invasion. Healthy adults (18–45 years of age) were randomized into ARMS-I or placebo group (50 subjects each). The drug was sprayed intra-orally (3× daily) for 75 days. The primary objectives were to establish whether ARMS-I decreased the frequency, severity or duration of URIs. Secondary objectives were to evaluate safety, tolerability, rate of virus detection, acceptability and adherence; effect on URI-associated absenteeism and medical visits; and effect of prior influenza vaccination on study outcomes.

Results

Of the 94 individuals who completed the study (placebo: n = 44, ARMS-I: n = 50), six presented with confirmed URI (placebo: 4, ARMS-I: 2), representing a 55% relative reduction, albeit this was statistically not significant). Influenza, coronavirus or rhinovirus were detected in three participants; all in the placebo group. Moreover, frequency of post-treatment exit visits was reduced by 55% in ARMS-I compared to the placebo group (N = 4 and 2, respectively). Fever was reported only in the placebo group. ARMS-I significantly reduced the frequency and severity of cough and sore throat, and duration of cough (P ≤ .019 for all comparisons). ARMS-I was safe, well tolerated, had high acceptability and high adherence to medication use. Medical visits occurred only in the placebo group while absenteeism did not differ between the two arms. Prior influenza vaccination had no effect on study outcome.

Conclusions

This randomized proof-of-concept clinical trial demonstrated that ARMS-I tended to provide protection against URIs in the enrolled study participants, while reducing severity and duration of cough and sore throat. A clinical trial with a larger number of study participants is warranted.

Trial registration

ClinicalTrials.gov NCT02644135 (retrospectively registered).

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2177-8) contains supplementary material, which is available to authorized users.

Vaccines in the Prevention of Viral Pneumonia

Pneumonia is of great global public health importance. Viral infections play both direct and indirect parts in its cause across the globe. Influenza is a leading cause of viral pneumonia in both children and adults, and respiratory syncytial virus is increasingly recognized as causing disease at both extremes of age. Vaccination offers the best prospect for prevention but current influenza vaccines do not provide universal and durable protection, and require yearly reformulation. In the future, it is hoped that influenza vaccines will give better and universal protection, and that new vaccines can be found for other causes of viral pneumonia.

Antiviral Medications in Seasonal and Pandemic Influenza

BACKGROUND

Amantadine, oseltamivir, and zanamivir are currently available in Germany for the prevention and treatment of influenza. We review their efficacy and side-effect profiles.

METHODS

This review is based on pertinent randomized and controlled trials (RCTs) and systematic reviews retrieved by a systematic literature search, and on other relevant literature.

RESULTS

The efficacy of antiviral drugs for the prevention of symptomatic influenza ranges from 60% to 90% (number needed to treat [NNT], 8-89) depending on the population and type of drug in question. Antiviral drugs shorten the duration of illness by 0.5-1.5 days when given within 48 hours of the onset of symptoms. Neuraminidase inhibitors do not significantly lower the incidence of bronchitis in adults, or of otitis media in children; they do have a positive effect against reported, but not necessarily diagnostically confirmed pneumonia in adults (NNT, 89 [50-232]). The RCTs yielded no information about possible effects on severe cases of influenza, or on mortality, as they included only mildly or moderately ill patients, but observational studies have yielded some evidence of benefit. The most common side effects of oseltamivir (>10%) are headache, nausea, and vomiting; of zanamivir (>1%), a skin rash; and of amantadine (>1%), loss of appetite, nausea, and central nervous effects.

CONCLUSION

The benefits of antiviral drugs, particularly neuraminidase inhibitors, outweigh their risks. In deciding whether to use them, physicians should consider the properties of the currently circulating viruses and the patient's individual risk constellation, as directed in clinical treatment recommendations.

The Clinical and Economic Impact of Probiotics Consumption on Respiratory Tract Infections: Projections for Canada

INTRODUCTION

There is accumulating evidence supporting the use of probiotics, which are defined as "live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host", as a preventive measure against respiratory tract infections (RTI). Two recent meta-analyses showed probiotic consumption (daily intake of 107 to 1010 CFU in any form for up to 3 months) significantly reduced RTI duration, frequency, antibiotic use and work absenteeism.

OBJECTIVES

The aim of this study was to assess the impact of probiotic use in terms of number of RTI episodes and days averted, and the number of antibiotic prescriptions and missed workdays averted, in the general population of Canada. In addition, the corresponding economic impact from both a healthcare payer and a productivity perspective was estimated.

METHODS

A microsimulation model was developed to reproduce the Canadian population (sample rate of 1/1000 = 35 540 individuals) employing age and gender. RTI incidence was taken from FluWatch consultation rates for influenza-like illness (2013-14) and StatCan all-cause consultations statistics. The model was calibrated on a 2.1% RTI annual incidence in the general population (5.2 million RTI days) and included known risk factors (smoking status, shared living conditions and vaccination status). RTI-related antibiotic prescriptions and work absenteeism were obtained from the literature.

RESULTS

The results indicate that probiotic use saved 573 000-2.3 million RTI-days, according to the YHEC-Cochrane scenarios respectively. These reductions were associated with an avoidance of 52 000-84 000 antibiotic courses and 330 000-500 000 sick-leave days. A projection of corresponding costs reductions amounted to Can$1.3-8.9 million from the healthcare payer perspective and Can$61.2-99.7 million when adding productivity losses.

CONCLUSION

The analysis shows that the potential of probiotics to reduce RTI-related events may have a substantial clinical and economic impact in Canada.

Passive immunization for influenza through antibody therapies, a review of the pipeline, challenges and potential applications

The Global Action Plan for influenza vaccines (GAP) aims to increase the production capacity of vaccines so that in the event of a pandemic there is an adequate supply to meet global needs. However, it has been estimated that even in the best case scenario there would be a considerable delay of at least five to six months for the first supplies of vaccine to become available after the isolation of the strain and availability of the candidate vaccine virus to vaccine manufacturers. By this time, the virus is likely to have already infected millions of people worldwide, causing significant mortality, morbidity and economic loss. Passive immunization through broadly neutralizing antibodies which bind to multiple, structurally diverse strains of influenza could be a promising solution to address the immediate health threat of an influenza pandemic while vaccines are being developed. These products may also have a role in seasonal influenza as an alternative to other options such as antivirals for the treatment of severe acute respiratory illness due to influenza. This article provides an overview of the current clinical pipeline of anti-influenza antibodies and discusses potential uses and the challenges to product development.

Improving data transparency in clinical trials using blockchain smart contracts

The scientific credibility of findings from clinical trials can be undermined by a range of problems including missing data, endpoint switching, data dredging, and selective publication. Together, these issues have contributed to systematically distorted perceptions regarding the benefits and risks of treatments. While these issues have been well documented and widely discussed within the profession, legislative intervention has seen limited success. Recently, a method was described for using a blockchain to prove the existence of documents describing pre-specified endpoints in clinical trials. Here, we extend the idea by using smart contracts - code, and data, that resides at a specific address in a blockchain, and whose execution is cryptographically validated by the network - to demonstrate how trust in clinical trials can be enforced and data manipulation eliminated. We show that blockchain smart contracts provide a novel technological solution to the data manipulation problem, by acting as trusted administrators and providing an immutable record of trial history.

Development of Seasonal Influenza Vaccination Recommendations: Relevance and Influence of the Evidence on the Decision-Making Process in France and the Netherlands

BACKGROUND

Target groups for seasonal influenza vaccination are defined at the country level and are based on several factors. However, little is known about the national decision-making procedures.

OBJECTIVE

The purpose of this study was to compare the evidence used for the development of recommendations and its impact on the choice of target groups in France and the Netherlands.

METHODS

A preliminary documentary analysis identified institutions to include in the assessment: governmental authorities, research institutions, associations, and manufacturers. At least one expert from each group was invited to our study. Thirty-three semi-structured interviews were conducted in 2013 (16 France, 17 the Netherlands). We used NVivo10® to perform a thematic content analysis.

RESULTS

Clinical/epidemiological studies were the evidence most used in both countries. Economic models were increasingly being used; these had greater influence on the decision making in the Netherlands than in France, probably because of the presence of a modeler. Generally, the quality of the evidence used was poor, although no systematic use of standard protocol for its assessment was observed. A general protocol was sometimes used in France; however, the personal judgment of the experts was crucial for the assessment in both countries.

CONCLUSIONS

There were differences in the target groups, for example, pregnant women, recommended only in France. France and the Netherlands use similar evidence for developing vaccination recommendations, although different decisions are sometimes made regarding target groups. This could be associated with the lack of systematic standard appraisals, increasing the influence of the experts' judgment on decision making. The development of standards for the appraisal of evidence is recommended.