The natural history of influenza infection in the severely immunocompromised vs nonimmunocompromised hosts

Contribution of immunoglobulin products in influencing seasonal influenza infection and severity in antibody immune deficiency patients receiving immunoglobulin replacement therapy

Seasonal and pandemic influenza infection present a potential threat to patients with antibody deficiency. The acceptance and effect of the current recommendation for annual vaccination against influenza for patients with antibody deficiency is not well investigated and due to antigenic drift or shift the protective capacity of regular IgG replacement therapy (IgRT) is considered low. This narrative review considers the effect of influenza vaccination in immunodeficient patients and discusses available information on the effect of immunoglobulin products on seasonal influenza infectivity and severity in antibody deficiency patients receiving IgRT. The humoral immune response to seasonal influenza vaccination is reduced in patients with antibody immune deficiency. However, there is no evidence that the proportion of patients with primary antibody deficiency who develop influenza illness, and the severity of such illness, is increased when compared with the general population. The IgRT that patients receive has been shown to contain neutralizing antibodies as a consequence of past flu infections against both the hemagglutinin and neuraminidase surface proteins and other viral internal proteins of different influenza A virus strains. Studies have demonstrated not only significant levels of specific but also cross-reactive antibodies against seasonal influenza virus strains. Thus, despite the yearly changes in influenza viral antigenicity that occur, IgRT could potentially contribute to the protection of patients against seasonal influenza. Currently, only limited clinical data are available confirming a preventative effect of IgRT with respect to seasonal influenza infection. In conclusion, there is some evidence that IgRT could contribute to protection against seasonal influenza in patients with antibody-related immunodeficiency. However, additional clinical data are needed to confirm the extent and relevance of this protection and identify the main responsible virus targets of that protection.

Determinants of influenza and COVID vaccine uptake in healthcare workers: A cross-sectional survey during the post-pandemic era in a network of academic hospitals in France

OBJECTIVES

Although influenza and COVID vaccines are recommended for healthcare workers (HCWs), vaccine coverage is sub-optimal for influenza in this population, and the situation did not improve during the COVID pandemic. We aimed to estimate influenza and COVID vaccine coverage among HCWs and their determinants after the COVID pandemic.

METHODS

We performed a cross-sectional study between May and July 2023 among HCWs to estimate influenza and COVID vaccination coverage during the 2022-2023 season, and its determinants, using a web-based anonymous questionnaire. We performed a multivariable regression analysis to assess factors associated with vaccine uptake.

RESULTS

Of the 9158 HCWs invited to participate, 1587 (16 %) completed the questionnaire, primarily paramedics (n = 479, 30 %), medics (n = 310, 20 %), administrative staff (n = 249, 16 %), and nurse assistants (n = 237, 15 %). Vaccine coverage during the 2022-2023 season was estimated at 64 % [CI95 % 61-66] for influenza, and 42 % [CI95% 39-44] for COVID. Vaccinated HCWs reported adverse events rates of 8 % (n = 122) after influenza, and 37 % (n = 579) after COVID vaccines. On multivariable analysis, being a medic or over 40 years old was associated with both influenza and COVID vaccine uptake. Suggested interventions to boost vaccine uptake were primarily to facilitate access to vaccination in the workplace, and to better inform HCWs on the risks and benefits of these vaccines.

CONCLUSIONS

Easy access to COVID and influenza vaccines in the workplace, and better information about their benefits, may improve their uptake. Future vaccination campaigns should communicate more about potential adverse effects, and effectiveness.

Seasonal Patterns of Common Respiratory Viral Infections in Immunocompetent and Immunosuppressed Patients

INTRODUCTION

Several respiratory viruses have been shown to have seasonal patterns. The aim of our study was to evaluate and compare these patterns in immunocompetent and immunosuppressed patients for five different respiratory viruses.

METHODS

We performed a retrospective analysis of results for 13,591 respiratory tract samples for human metapneumovirus (HMPV), influenza virus, parainfluenza virus (PIV) and respiratory syncytial virus (RSV) in immunocompetent and immunosuppressed patients. A seasonal pattern was aligned to the data of immunocompetent patients through a logistic regression model of positive and negative test results.

RESULTS

A narrow seasonal pattern (January to March) was documented for HMPV. Most RSV infections were detected in the winter and early spring months, from December to March, but occasional cases of RSV could be found throughout the year. The peak season for PIV-3 was during the summer months, and that for PIV-4 was mostly in autumn. A narrow seasonal pattern emerged for influenza virus as most infections were detected in the winter, in January and February. The seasonal patterns of HMPV, RSV, PIV, and influenza virus were similar for both immunocompetent and immunocompromised patients.

CONCLUSIONS

We found no difference in the seasonality of HMPV, RSV, PIV, and influenza virus infections between immunosuppressed and immunocompetent hosts.

Pulmonary MicroRNA expression after heterologous challenge with swine influenza A virus (H1N2) in immunized and non-immunized pigs

MicroRNAs (miRNAs) contribute to post-transcriptional modulation of the host response during influenza A virus (IAV) infection and may be involved in shaping disease severity. Differential disease severity was achieved in two groups of pigs by immunization of one group with a commercial swine IAV vaccine prior to heterologous IAV (H1N2) challenge of both groups. Lung tissue was harvested 1, 3, and 14 days after challenge and miRNA expression was quantified. Gene Ontology term enrichment analysis was employed to examine the functional relevance of genes potentially regulated by differentially expressed miRNAs in pigs with varying degrees of disease severity following IAV infection. Results suggested that the miRNA response associated with less severe disease may modulate host mechanisms essential for viral life cycle, e.g. transcription, translation, and protein trafficking. During more severe disease, miRNA-mediated regulation may focus on dampening virus-specific processes e.g. virion assembly and viral protein processing, and controlling host metabolism.

Protective Effects from Prior Pneumococcal Vaccination in Patients with Chronic Airway Diseases during Hospitalization for Influenza-A Territory-Wide Study

Influenza is an important respiratory viral pathogen in adults, with secondary bacterial pneumonia being a common complication. While pneumococcal vaccines can prevent pneumococcal pneumonia and invasive pneumococcal disease, whether they can also prevent the severe in-hospital outcomes among patients hospitalized for influenza has not been examined. A territory-wide retrospective study was conducted in Hong Kong, which included all adult patients having chronic airway diseases (asthma, bronchiectasis, and chronic obstructive pulmonary disease) hospitalized for influenza and who had received seasonal influenza vaccine. The occurrence of secondary bacterial pneumonia, mortality, and other severe in-hospital outcomes were compared among subjects with or without pneumococcal vaccination. There was a total of 3066 eligible patients who were hospitalized for influenza in public hospitals in Hong Kong from 1 January 2016 to 30 June 2023. Completed pneumococcal vaccination with PSV23/PCV13 conferred protection against secondary bacterial pneumonia, all-cause mortality, and respiratory cause of mortality with adjusted odds ratios of 0.74 (95% CI = 0.57-0.95, p = 0.019), 0.12 (95% CI = 0.03-0.53, p = 0.005), and 0.04 (95% CI = 0.00-0.527, p = 0.0038), respectively.

Unveiling the Shadows: A Rare Encounter With Cardiac Tamponade Following Influenza B in a Young Female

Influenza B infection, although primarily recognized for respiratory symptoms, can lead to rare but severe cardiac complications such as pericardial effusion and cardiac tamponade. We present a case of a 33-year-old female with morbid obesity who initially exhibited flu-like symptoms, was subsequently diagnosed with influenza B infection, and was discharged with symptomatic treatment. Despite initial discharge, she returned with worsening weakness, gastrointestinal symptoms, and shortness of breath. Imaging studies confirmed pericardial effusion with early signs of tamponade, necessitating an emergent intervention. The patient underwent subxiphoid pericardial window and fluid removal, followed by colchicine treatment to prevent recurrence. Our case highlights the importance of recognizing and promptly managing rare influenza-related complications, particularly in patients without significant comorbidities. It underscores the value of a proactive approach, utilizing point-of-care ultrasound and echocardiography for early diagnosis and intervention to mitigate mortality and morbidity risks associated with pericarditis and cardiac tamponade secondary to influenza B.

Cerebral Anoxia in an 18-year-old Patient Being Treated for Major Depressive Disorder: How Forensic Detective Work Uses Medical Knowledge Including Clinical Pharmacology to Solve Cases

This column is the first of a 3-part series illustrating the importance of medical knowledge, including clinical pharmacology, in a forensic context. This first case involved an 18-year-old high school student who suffered an anoxic brain injury and remained in a state of permanent decorticate posture, unresponsive except for grunts and primitive movements until he died several years later. Our investigation began by ruling out plausible causes that were suggested by the defense in the malpractice suit. Once those possibilities were eliminated, the focus was on what accounted for the damage to the patient using general medical knowledge and clinical pharmacology. The 4 Ds of forensic psychiatry (duty, damages, dereliction, and direct cause) are the 4 elements that the plaintiff is required to prove in civil court to prevail in a malpractice suit and are applied to this case with a special focus on dereliction and direct cause. This catastrophic outcome was due to 3 factors. First, the patient had physiologically significant dehydration to the point that he had developed a reflex tachycardia to maintain his blood pressure. Second, the patient had been switched from extended to immediate-release quetiapine, resulting in a doubling of the peak concentration of the drug, which produced higher occupancy of alpha-1 adrenergic, histamine-1, and dopamine-2 receptors, causing a further drop in his blood pressure as well as increased sedation and impairment of his gag reflex. These effects occurred quickly because of the faster absorption of the IR formulation of the drug. Third, the patient had gone to sleep in a reclining chair so that his brain was above his heart and his lower extremities were below his heart, resulting in an increased "steal" of cardiac output going to his brain. These 3 factors together led the patient to aspirate and suffer a hypoxic brain injury after an episode of vomitus. This column explains the process by which the cause of this sad outcome was determined, how it was related to a dereliction of duty to the patient, and how other proposed causes were ruled out.

Outlining recent updates on influenza therapeutics and vaccines: A comprehensive review

Influenza virus has presented a considerable healthcare challenge during the past years, particularly in vulnerable groups with compromised immune systems. Therapeutics and vaccination have always been in research annals since the spread of influenza. Efforts have been going on to develop an antiviral therapeutic approach that could assist in better disease management and reduce the overall disease complexity, resistance development, and fatality rates. On the other hand, vaccination presents a chance for effective, long-term, cost-benefit, and preventive response against the morbidity and mortality associated with the influenza. However, the issues of resistance development, strain mutation, antigenic variability, and inability to cure wide-spectrum and large-scale strains of the virus by available vaccines remain there. The article gathers the updated data for the therapeutics and available influenza vaccines, their mechanism of action, shortcomings, and trials under clinical experimentation. A methodological approach has been adopted to identify the prospective therapeutics and available vaccines approved and within the clinical trials against the influenza virus. Review contains influenza therapeutics, including traditional and novel antiviral drugs and inhibitor therapies against influenza virus as well as research trials based on newer drug combinations and latest technologies such as nanotechnology and organic and plant-based natural products. Most recent development of influenza vaccine has been discussed including some updates on traditional vaccination protocols and discussion on next-generation and upgraded novel technologies. This review will help the readers to understand the righteous approach for dealing with influenza virus infection and for deducing futuristic approaches for novel therapeutic and vaccine trials against Influenza.

Genome characterization of influenza A and B viruses in New South Wales, Australia, in 2019: A retrospective study using high-throughput whole genome sequencing

BACKGROUND

During the 2019 severe influenza season, New South Wales (NSW) experienced the highest number of cases in Australia. This study retrospectively investigated the genetic characteristics of influenza viruses circulating in NSW in 2019 and identified genetic markers related to antiviral resistance and potential virulence.

METHODS

The complete genomes of influenza A and B viruses were amplified using reverse transcription-polymerase chain reaction (PCR) and sequenced with an Illumina MiSeq platform.

RESULTS

When comparing the sequencing data with the vaccine strains and reference sequences, the phylogenetic analysis revealed that most NSW A/H3N2 viruses (n = 68; 94%) belonged to 3C.2a1b and a minority (n = 4; 6%) belonged to 3C.3a. These viruses all diverged from the vaccine strain A/Switzerland/8060/2017. All A/H1N1pdm09 viruses (n = 20) showed genetic dissimilarity from vaccine strain A/Michigan/45/2015, with subclades 6B.1A.5 and 6B.1A.2 identified. All B/Victoria-lineage viruses (n = 21) aligned with clade V1A.3, presenting triple amino acid deletions at positions 162-164 in the hemagglutinin protein, significantly diverging from the vaccine strain B/Colorado/06/2017. Multiple amino acid substitutions were also found in the internal proteins of influenza viruses, some of which have been previously reported in hospitalized influenza patients in Thailand. Notably, the oseltamivir-resistant marker H275Y was present in one immunocompromised patient infected with A/H1N1pdm09 and the resistance-related mutation I222V was detected in another A/H3N2-infected patient.

CONCLUSIONS

Considering antigenic drift and the constant evolution of circulating A and B strains, we believe continuous monitoring of influenza viruses in NSW via the high-throughput sequencing approach provides timely and pivotal information for both public health surveillance and clinical treatment.

Adult vaccination against respiratory infections in Egypt: a review of expert opinions

INTRODUCTION

Lower respiratory tract infection is one of the leading causes of morbidity and mortality all over the world, with a substantial impact on healthcare costs. In Egypt, local consensus on its burden, diagnosis, and vaccination is scarce. This expert opinion is the first to address the local recommendations for vaccinating adults against respiratory infection. It sheds light on the growing need to understand the barriers and underpublicized concept of adult vaccination in Egypt.

AREAS COVERED

A collaborative multidisciplinary panel from Egypt developed an expert opinion-based suggestions/points, including epidemiology, microbiology, and highlights on vaccination in Egypt, as well as challenges and recommendations regarding adult vaccination.

EXPERT OPINION

Adult vaccinations against respiratory infections are now recommended for high-risk people by all healthcare regulatory bodies. However, it was acknowledged that there may be hesitancy and concerns among patients; in addition, healthcare professionals' awareness about vaccination guidelines and benefits needs improvement. There are several strategies that could be implemented to enhance vaccine adherence in Egypt. These approaches encompass conducting community education programs, addressing the concerns of patients, and enhancing awareness among healthcare professionals through education, policy changes, and periodical reminders in each healthcare setting.

Evaluation of Hospitalized Patients with Community-Acquired Influenza-Like Illness During Two Influenza Seasons

Objective

Influenza is among the most important respiratory infections affecting all age groups and can lead to hospitalizations. We aimed to determine the frequency of influenza infections among acute admissions with influenza-like illness (ILI) and evaluate the demographic, clinical findings, and outcomes of patients with influenza.

Methods

This prospective, active surveillance study was conducted in a university hospital between 2015 and 2017. Patients hospitalized for at least 24 hours in the selected units with community-acquired ILI were screened according to certain influenza-predicting ICD-10 codes. Nasopharyngeal and pharyngeal swab samples were taken from patients who were eligible for the study. Patients tested for influenza with real-time polymerase chain reaction. Univariate and multivariate analyses were performed for data.

Results

Among 440 patients screened according to influenza-related ICD-10 codes, 112 were included. Influenza positivity was detected in 37 of the 112 patients. Clinical findings were similar between influenza positive and negative groups and also between influenza subtypes, excluding sore throat, which was more common in the H1N1 group. Alanine transaminase (ALT), aspartate transaminase (AST), and creatine kinase (CK) elevations were found to be significantly higher in the influenza-positive group. When influenza-positive patients with and without pneumonia were compared, the rate of vaccination in the same season was higher in patients without pneumonia than in patients with pneumonia (38.8% and 10.5%, respectively; p=0.04).

Conclusion

Integrating molecular tests detecting both influenza and other respiratory viruses into influenza surveillance programs can increase the efficacy and quality of these programs. The elevation of AST, ALT, and CK in influenza cases can be considered in distinguishing influenza from other ILI cases. Vaccination in the same season can reduce the risk of pneumonia in influenza-positive patients.

Influenza vaccine coverage among healthcare workers: A cluster analysis from a cross-sectional survey

OBJECTIVES

Influenza vaccination is recommended for healthcare workers (HCWs). However, in a 1500-bed tertiary care university hospital in France, influenza vaccine coverage among HCWs was 23% in 2017.

PATIENTS AND METHODS

We performed a cross-sectional study between 05/09/2018 and 25/09/2018 among HCWs, randomly selected independent of their vaccination status, to estimate influenza vaccination coverage rate during the 2017-2018 season, and explore factors influencing vaccination, using a questionnaire. Multivariable regression analysis to assess factors associated with vaccine uptake and hierarchical clustering on principal components to identify HCW profiles regarding factors influencing vaccine uptake, were performed after multiple imputation.

RESULTS

977 HCWs were included (68% participation rate), primarily females (84%), nurses (38%) of 18-39 years old. Influenza vaccination coverage rate reached 33[30-36]%. Frequent vaccination (aOR 39.27[21.52-74.51]) and personal/family medical history of influenza (aOR 3.33[1.16-10.02]) were independently associated with vaccination. In HCWs' patterns of influenza vaccination status, three clusters were identified: 1) (n = 438) mostly vaccinated (70%); 2) (n = 507) most unvaccinated (97%); and 3) (n = 32) unvaccinated HCWs lacking knowledge on influenza and influenza vaccine. Among the 148 (15%) HCWs reluctant to receive the vaccine the following year, 23 (16%) received it for the 2017-2018 season, while 125 (84%) did not, mostly stating they had doubts about the vaccine (82%).

CONCLUSION

This work identifies determinants of vaccine uptake and highlights HCWs profiles associated with factors influencing vaccination and a subgroup of HCWs flexible about having the vaccine during the upcoming seasonal campaign. This result opens up perspectives toward improved vaccination coverage among HCWs.

Burden of influenza A (H1N1)pdm09 infection among tuberculosis patients: a prospective cohort study

BACKGROUND

Influenza and tuberculosis both cause significant morbidity and mortality worldwide. Therefore, this study aimed to estimate the burden of influenza A (H1N1)pdm09 virus infection among human tuberculosis patients and the general population.

METHODS

A prospective cohort study was conducted among a cohort group (TB positive patients) as exposed and a comparison group (general population) as non-exposed. A total of 304 participants were recruited in both groups and followed for a period of 12 weeks. Of the 304 concurrently enrolled individuals, 152 were TB-positive patients (cohort group) and 152 were from the general population (comparison group).To calculate the sample size, the power of study was kept at 80% for detecting a difference at 5% alpha level assuming the 25% prevalence of respiratory viruses in cohort group compared to 12.5% in general population. An oropharyngeal swab was taken from a participant with symptoms of influenza-like illness (ILI). Samples were tested by conventional reverse transcription polymerase chain reaction (RT-PCR) for the detection of influenza A (H1N1)pdm09. All statistical analyses were conducted using R software.

RESULTS

A total of 95 participants developed influenza-like illness (ILI) symptoms. Among these, 64 tested positive for influenza A(H1N1)pdm09, of which 39 were from the exposed group and 25 were from the non-exposed group. During the 12-week period of follow-up, the influenza A (H1N1)pdm09 incidence rate was 20 per 1000 people. The risk of testing positive for influenza A (H1N1)pdm09 was 1.66 times higher in the exposed group compared to the non-exposed group. The cumulative incidence indicated that 25% of the TB cohort and 16% of the comparison group were at risk of getting influenza A (H1N1)pdm09 during the 12 weeks of follow-up.

CONCLUSION

Participants from the TB cohort had a higher incidence of influenza A (H1N1)pdm09 than the general population suggesting that they should be prioritized for influenza vaccination.

Effectiveness of prolonged versus standard-course of oseltamivir in critically ill patients with severe influenza infection: A multicentre cohort study

The aim of this study is to investigate the effectiveness of prolonged versus standard course oseltamivir treatment among critically ill patients with severe influenza. A retrospective study of a prospectively collected database including adults with influenza infection admitted to 184 intensive care units (ICUs) in Spain from 2009 to 2018. Prolonged oseltamivir was defined if patients received the treatment beyond 5 days, whereas the standard-course group received oseltamivir for 5 days. The primary outcome was all-cause ICU mortality. Propensity score matching (PSM) was constructed, and the outcome was investigated through Cox regression and RCSs. Two thousand three hundred and ninety-seven subjects were included, of whom 1943 (81.1%) received prolonged oseltamivir and 454 (18.9%) received standard treatment. An optimal full matching algorithm was performed by matching 2171 patients, 1750 treated in the prolonged oseltamivir group and 421 controls in the standard oseltamivir group. After PSM, 387 (22.1%) patients in the prolonged oseltamivir and 119 (28.3%) patients in the standard group died (p = 0.009). After adjusting confounding factors, prolonged oseltamivir significantly reduced ICU mortality (odds ratio [OR]: 0.53, 95% confidence interval [CI]: 0.40-0.69). Prolonged oseltamivir may have protective effects on survival at Day 10 compared with a standard treatment course. Sensitivity analysis confirmed these findings. Compared with standard treatment, prolonged oseltamivir was associated with reduced ICU mortality in critically ill patients with severe influenza. Clinicians should consider extending the oseltamivir treatment duration to 10 days, particularly in higher-risk groups of prolonged viral shedding. Further randomized controlled trials are warranted to confirm these findings.

Review of the unmet medical need for vaccination in adults with immunocompromising conditions: An Indian perspective

Immunocompromised (IC) populations are at increased risk of vaccine-preventable diseases (VPDs). In India, the concern of VPDs in IC populations is particularly acute due to the prevalence of crowded living situations, poor sanitation and variable access to healthcare services. We present a narrative review of IC-related disease and economic burden, risk of VPDs and vaccination guidelines, based on global and India-specific literature (2000-2022). IC conditions considered were cancer, diabetes mellitus, chronic kidney disease, respiratory disorders, disorders treated with immunosuppressive therapy, and human immune deficiency virus (HIV). The burden of IC populations in India is comparable to the global population, except for cancer and HIV, which have lower prevalence compared with the global average. Regional and socioeconomic inequalities exist in IC prevalence; VPDs add to the burden of IC conditions, especially in lower income strata. Adult vaccination programs could improve health and reduce the economic impact of VPDs in IC populations.

Influenza-like illness in individuals treated with immunosuppressants, biologics, and/or systemic corticosteroids for autoimmune or chronic inflammatory disease: A crowdsourced cohort study, France, 2017-2018

BACKGROUND

Influenza-like illness (ILI) incidence estimates in individuals treated with immunosuppressants and/or biologics and/or corticosteroid for an autoimmune or chronic inflammatory disease are scarce. We compared the ILI incidence among immunocompromised population and the general population.

METHOD

We conducted a prospective cohort study during the 2017-2018 seasonal influenza epidemic, on the GrippeNet.fr electronic platform, which allows the collection of epidemiological crowdsourced data on ILI, directly from the French general population. The immunocompromised population were adults treated with systemic corticosteroids, immunosuppressants, and/or biologics for an autoimmune or chronic inflammatory disease, recruited directly on GrippeNet.fr and also among patients of the departments of a single university hospital that were asked to incorporate GrippeNet.fr. The general population consisted of adults reporting none of the above treatments or diseases participating in GrippeNet.fr. The incidence of ILI was estimated on a weekly basis and compared between the immunocompromised population and the general population, during the seasonal influenza epidemic.

RESULTS

Among the 318 immunocompromised patients assessed for eligibility, 177 were included. During the 2017-2018 seasonal influenza epidemic period, immunocompromised population had 1.59 (95% CI: 1.13-2.20) higher odds to experience an ILI episode, compared to the general population (N = 5358). An influenza vaccination was reported by 58% of the immunocompromised population, compared to 41% of the general population (p < 0.001).

CONCLUSION

During a seasonal influenza epidemic period, the incidence of influenza-like illness was higher in patients treated with immunosuppressants, biologics, and/or corticosteroids for an autoimmune or chronic inflammatory disease, compared to the general population.

Phylogenetic analysis of HA and NA genes of influenza A viruses in immunosuppressed inpatients in Beijing during the 2018-2020 influenza seasons

BACKGROUND

Influenza A viruses have undergone rapid evolution with virulent; however, complete and comprehensive data on gene evolution and amino acid variation of HA and NA in immunosuppressed patients was few. In this study, we analysed molecular epidemiology and evolution of influenza A viruses in immunosuppressed population, and immunocompetent population were used as controls.

METHODS

Full sequences of HA and NA of A(H1N1)pdm09 and A(H3N2) were acquired through reverse transcription-polymerase chain reaction (RT-PCR). HA and NA genes were sequenced using the Sanger method and phylogenetically analysed using ClustalW 2.10 and MEGA software version 11.0.

RESULTS

During the 2018-2020 influenza seasons, 54 immunosuppressed and 46 immunocompetent inpatients screened positive for influenza A viruses by using the quantitative real-time PCR (qRT-PCR) were enrolled. 27 immunosuppressed and 23 immunocompetent nasal swab or bronchoalveolar lavage fluid samples were randomly selected and sequenced using the Sanger method. A(H1N1)pdm09 were detected in 15 samples and the remaining 35 samples were A(H3N2) positive. By analyzing the HA and NA gene sequences of these virus strains, we found that all A(H1N1)pdm09 viruses shared high similarities to each other and the HA and NA genes of these viruses exclusively belonged to subclade 6B.1A.1. Some NA genes of A(H3N2) viruses were not in the same clade as those of A/Singapore/INFIMH-16-0019/2016 and A/Kansas/14/2017, which may have led to A(H3N2) being the dominant strain in the 2019-2020 influenza season. Both A(H1N1)pdm09 and A(H3N2) viruses showed similar evolutionary lineages patterns of HA and NA between immunosuppressed and immunocompetent patients. Compared with the vaccine strains, there were no statistically significant of HA and NA genes and amino acid sequences of influenza A viruses in immunosuppressed and immunocompetent patients. However, the oseltamivir resistance substitution of NA-H275Y and R292K have been observed in immunosuppressed patients.

CONCLUSIONS

A(H1N1)pdm09 and A(H3N2) viruses showed similar evolutionary lineages patterns of HA and NA between immunosuppressed and immunocompetent patients. Both immunocompetent and immunosuppressed patients have some key substitutions, which should be of note monitored, especially those with potential to affect the viral antigen.

Factors associated with poor outcomes in patients with severe acute respiratory infections in Bahrain

Background

Severe acute respiratory tract infection (SARI) is a major global health threat. This study aimed to examine risk factors associated with poor outcomes in patients with SARI.

Methods

All patients who met World Health Organization's (WHO) SARI case definition and were admitted to Salmaniya Medical Complex from January 2018 to December 2021 were included. Epidemiological and virological data were obtained and analyzed.

Results

Of 1159 patients with SARI included, 731 (63.1%) patients were below 50 years, and 357 (30.8%) tested positive for viral pathogens. The most prevalent virus was Flu-A (n = 134, 37.5%), SARS-CoV2 (n = 118, 33%), RSV (n = 51, 14.3%), Flu B (n = 49,13.7%), other viruses (n = 3, 0.8%), and combined infection (n = 2, 0.6%). Six hundred fifty-eight (56.8%) patients had comorbidities, mainly diabetes (n = 284, 43%) and heart disease (n = 217, 33%). 183 (16%) patients were admitted to ICU, 110 (9%) needed mechanical ventilation, and 80 (7%) patients died.The odds of ICU admission were higher for patients with hematological (OR 5.9, 95% CI 3.1-11.1) and lung diseases (OR 2.7, 95% CI 1.6-4.6). The odds of mechanical ventilation were higher among patients with lung disease (OR 3.1, 95% 1.7-5.5). The mortality odds were higher among patients above 50 (OR 2.4, 95% CI 1.4-4.1) and chronic kidney disease (OR 2.5, 95% CI 1.1-5.2).

Conclusions

Being 50 years or above or having kidney, lung, or heart diseases was associated with worse SARI outcomes. Efforts and actions in developing better strategies to vaccinate individuals at high risk and early diagnosis and treatment should help in reducing the burden of SARI.

Psychological distress experienced by parents caring for an immunosuppressed child during the COVID-19 pandemic

The COVID-19 pandemic has proved unique in both its unpredictability and the extent to which it has continued to impact on daily life since March 2020. Among the immunosuppressed population the challenges of the COVID-19 pandemic are cumulative to the ever-present challenges of living with a long-term condition. This prospective longitudinal study explored patterns of concern experienced by 467 British parents caring for an immunosuppressed child during the first 2 years of the COVID-19 pandemic and related this to parental mental wellbeing. Most parents slowly adapted or were resilient to the ever-changing stressors of the COVID-19 pandemic. However, 12% experienced high levels of concern throughout the first 2 years of the pandemic. This group was also more likely to report emotional mental health problems towards the end of this period. The experience of emotional mental health problems among parents caring for an immunosuppressed child was related to low household income, single parenting, difficult access to greenspace, and higher level of exposure to COVID positive cases and COVID restrictions (North of England). Parents reported that optimism, reduction of isolation, and support promoted coping and management of the challenges of the COVID-19 pandemic. More reliable COVID information and periodic medical-condition-specific guidance would have been appreciated. These findings can increase clinical awareness of high-risk parental groups and make an important contribution to the planning of appropriate targeted psychological family interventions.

Mortality in cancer patients with SARS-CoV-2 or seasonal influenza: an observational cohort study from a German-wide hospital network

PURPOSE

At the beginning of the COVID-19 pandemic, SARS-CoV-2 was often compared to seasonal influenza. We aimed to compare the outcome of hospitalized patients with cancer infected by SARS-CoV-2 or seasonal influenza including intensive care unit admission, mechanical ventilation and in-hospital mortality.

METHODS

We analyzed claims data of patients with a lab-confirmed SARS-CoV-2 or seasonal influenza infection admitted to one of 85 hospitals of a German-wide hospital network between January 2016 and August 2021.

RESULTS

29,284 patients with COVID-19 and 7442 patients with seasonal influenza were included. Of these, 360 patients with seasonal influenza and 1625 patients with COVID-19 had any kind of cancer. Cancer patients with COVID-19 were more likely to be admitted to the intensive care unit than cancer patients with seasonal influenza (29.4% vs 24.7%; OR 1.31, 95% CI 1.00-1.73 p < .05). No statistical significance was observed in the mechanical ventilation rate for cancer patients with COVID-19 compared to those with seasonal influenza (17.2% vs 13.6% OR 1.34, 95% CI 0.96-1.86 p = .09). 34.9% of cancer patients with COVID-19 and 17.9% with seasonal influenza died (OR 2.45, 95% CI 1.81-3.32 p < .01). Risk factors among cancer patients with COVID-19 or seasonal influenza for in-hospital mortality included the male gender, age, a higher Elixhauser comorbidity index and metastatic cancer.

CONCLUSION

Among cancer patients, SARS-CoV-2 was associated with a higher risk for in-hospital mortality than seasonal influenza. These findings underline the need of protective measurements to prevent an infection with either COVID-19 or seasonal influenza, especially in this high-risk population.

The Role of Immunosuppression in the Development of COVID-19 in Systemic Lupus Erythematosus Patients: A Brief Report

Recently, due to the coronavirus disease 2019 (COVID-19) pandemic, much concern has been raised about patients with chronic diseases who may become more susceptible to the disease. The present cross-sectional study aimed to characterize the clinical course of COVID-19 in patients with systemic lupus erythematosus (SLE). In addition, a possible correlation between the immunosuppression state and the incidence of COVID-19 is investigated. In May 2020, 500 SLE patients registered in the database of Golestan Rheumatology Research Center (Golestan province, Iran) were selected for this cross-sectional study. Using a questionnaire, patients were contacted by telephone to collect data including demographic characteristics, disease status, drug use, and new clinical symptoms. Data were analyzed using SPSS software version 24.0. Of the 500 selected patients, 355 responded to the phone calls and subsequently enrolled in the study. Among the enrolled patients, 25 were classified as COVID-19 positive, including eight hospitalized patients, of which two required intensive care and subsequently died. COVID-19 incidence was significantly lower in the immunosuppressed patients (2.2% vs. 10%, P=0.01). There was no significant correlation between hydroxychloroquine consumption and the incidence of COVID-19 in SLE patients. Fever, fatigue, dyspnea, and dry cough were the most common clinical symptoms. Our results showed that COVID-19 incidence was lower in immunosuppressed than the non-immunosuppressed SLE patients. Further studies are required to substantiate the role of immunosuppression in the development of COVID-19. A preprint version of this study was published at https://www.researchsquare.com/article/rs-78704/v1 with doi: https://doi.org/10.21203/rs.3.rs-78704/v1.

Clinical features and outcome of influenza pneumonia in critically-ill immunocompromised patients

Immunocompromised subjects are at risk of severe viral infections which may require intensive care unit (ICU) admission. Data on the outcome of influenza pneumonia in critically-ill immunocompromised subjects are limited. We conducted a single-center observational study. All subjects admitted to the ICU for influenza pneumonia between 2016 and 2020 were included. The main objective was to compare the clinical features and outcome of critically-ill subjects with flu according to their immune status. 137 subjects (age 60 years-old, 58.4% male) were included, of whom 58 (42.34%) were intubated during the ICU stay. Forty-three (31.4%) subjects were immunocompromised. Immunocompromised subjects had a higher Charlson comorbidity index. In contrast, severity scores and hypoxemia at ICU admission, and ventilatory support during ICU stay were similar between the 2 groups. There was no difference in the rate of co-infections and ventilator-associated pneumonia between the 2 groups. Among intubated subjects, 10 (23.26%) immunocompromised subjects developed severe acute respiratory distress syndrome compared to 13 (13.83%) non-immunocompromised (P = .218). ICU mortality was 13.97%, with mortality being 3-times higher in immunocompromised subjects (25.58% vs 8.6%, P = .015). On multivariable analysis, immunocompromised status, higher age and lower arterial oxygen partial pressure/fraction of inspired oxygen were associated with an increased ICU mortality. Immunocompromised subjects with severe influenza pneumonia were more likely to develop severe acute respiratory distress syndrome and had a 3-fold increase in ICU mortality compared to non-immunocompromised subjects. Such difference was not explained by an increased rate of co-infections or nosocomial pneumonia, suggesting that influenza virus was by itself responsible of a more severe form of pulmonary disease in immunocompromised subjects.

Parental concern for clinically vulnerable child during first 18 months of the COVID pandemic

BACKGROUND

The uncertainties surrounding the COVID-19 pandemic have been associated with increased parental concern. The aim of this study is to explore if this increased level of concern is associated with certain individual/household characteristics or if parents adapted to the ever-changing realities of the COVID-19 pandemic over time.

METHODS

This prospective study explored COVID-19 concern trajectories and associated family characteristics of 765 UK parents caring for an immunosuppressed child during the first 18 months of the pandemic using growth mixture modelling. Qualitative analysis was performed to examine in more detail the source of concern.

RESULTS

Four different trajectories of parental COVID-19 concern were identified. Ongoing very high concern was associated with caring for children with nephrotic or respiratory disease; having a child on an organ transplant waiting list; residency in the North of England; or parental vocational inactivity. Explicit concerns voiced by the parents generally followed national trends, but vulnerable status specific concerns were also reported.

CONCLUSION

Diagnosis and prescribed medication of the immunosuppressed child, geographical location, household composition, and employment status of parent were associated with the different concern trajectories. This information can be helpful in targeting psychological family care where it is most needed.

IMPACT

Many British parents caring for a clinically vulnerable child during the first 18 months of the COVID-19 pandemic showed high levels of concern with little sign of psychological adaptation. Consistent with findings from non-vulnerable populations, parents mentioned the impact of shielding and repeated isolation on their child's education, social life, and mental health. Unique to the clinically vulnerable population, parents were worried about child's health status, impact of delayed healthcare, and were confused by the contradictory information received from government, doctors, and media. Psychological family care can be targeted to those parents at greater risk for high levels of concern.

Antiviral Peptides as Anti-Influenza Agents

Influenza viruses represent a leading cause of high morbidity and mortality worldwide. Approaches for fighting flu are seasonal vaccines and some antiviral drugs. The development of the seasonal flu vaccine requires a great deal of effort, as careful studies are needed to select the strains to be included in each year's vaccine. Antiviral drugs available against Influenza virus infections have certain limitations due to the increased resistance rate and negative side effects. The highly mutative nature of these viruses leads to the emergence of new antigenic variants, against which the urgent development of new approaches for antiviral therapy is needed. Among these approaches, one of the emerging new fields of "peptide-based therapies" against Influenza viruses is being explored and looks promising. This review describes the recent findings on the antiviral activity, mechanism of action and therapeutic capability of antiviral peptides that bind HA, NA, PB1, and M2 as a means of countering Influenza virus infection.

Influenza

Annual seasonal influenza epidemics of variable severity caused by influenza A and B virus infections result in substantial disease burden worldwide. Seasonal influenza virus circulation declined markedly in 2020-21 after SARS-CoV-2 emerged but increased in 2021-22. Most people with influenza have abrupt onset of respiratory symptoms and myalgia with or without fever and recover within 1 week, but some can experience severe or fatal complications. Prevention is primarily by annual influenza vaccination, with efforts underway to develop new vaccines with improved effectiveness. Sporadic zoonotic infections with novel influenza A viruses of avian or swine origin continue to pose pandemic threats. In this Seminar, we discuss updates of key influenza issues for clinicians, in particular epidemiology, virology, and pathogenesis, diagnostic testing including multiplex assays that detect influenza viruses and SARS-CoV-2, complications, antiviral treatment, influenza vaccines, infection prevention, and non-pharmaceutical interventions, and highlight gaps in clinical management and priorities for clinical research.

Antiviral therapy for COVID-19: Derivation of optimal strategy based on past antiviral and favipiravir experiences

Favipiravir, a broad-spectrum RNA-dependent RNA polymerase inhibitor, inhibits the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at significantly lower concentrations than the plasma trough levels achieved by the dosage adopted for influenza treatment and exhibits efficacy against coronavirus disease 2019 (COVID-19) pneumonia. Although high doses of favipiravir are required due to the molecule being a purine analog, its conversion into the active form in infected cells with active viral RNA synthesis enhances the antiviral specificity and selectivity as a chain terminator with lethal mutagenesis. Another characteristic feature is the lack of generation of favipiravir-resistant virus. COVID-19 pneumonia is caused by strong cell-mediated immunity against virus-infected cells, and the inflammatory response induced by adaptive immunity continues to peak for 3 to 5 days despite antiviral treatment. This has also been observed in herpes zoster (HZ) and cytomegalovirus (CMV) pneumonia. Inflammation due to an immune response may mask the effectiveness of favipiravir against COVID-19 pneumonia. Favipiravir significantly shortened the recovery time in patients with mild COVID-19 pneumonia by 3 days with the start of treatment by the 5th day of symptom onset. Since both CMV and COVID-19 pneumonia are caused by adaptive immunity and prevention of cytomegalovirus pneumonia is the standard treatment due to difficulties in treating refractory CMV pneumonia, COVID-19 pneumonia should be prevented with early treatment as well. In the present study, we have comprehensively reviewed the optimal antiviral therapy for COVID-19 based on clinical trials of favipiravir for the treatment of COVID-19 pneumonia and the concurrently established therapies for other viral infections, particularly HZ and CMV pneumonia. Optimally, antivirals should be administered immediately after COVID-19 diagnosis, similar to that after influenza diagnosis, to prevent COVID-19 pneumonia and complications resulting from microangiopathy.

Outcomes following diabetes admission in patients who had influenza vaccination: A population-based cohort study

OBJECTIVE

The beneficial effect of influenza vaccination (IV) in patients with diabetes was not completely understood.

METHODS

Using the research data of health insurance, we performed a cohort study of patients aged ≥20 years who were admitted to inpatient care due to diabetes in 2008-2013 in Taiwan. We performed the propensity score matching and the outcomes of complications and mortality following the diabetes admission was compared between patients with and without IV.

RESULTS

Among 61,002 patients with diabetes admission, IV reduced 30-day in-hospital mortality (odds ratio [OR] 0.75, 95% confidence interval [CI] 0.66-0.84), particularly among patients with prior diabetes hospitalization, inadequate control for diabetes, and diabetes-related comorbidities, such as eye involvement, ketoacidosis, renal manifestations, and coma. Compared with non-IV control group, patients with IV also had decreased risks of pneumonia (OR 0.92, 95% CI 0.87-0.97), septicemia (OR 0.83, 95% CI 0.79-0.88), urinary tract infection (OR 0.94, 95% CI 0.90-0.97), and intensive care (OR 0.29, 95% CI 0.27-0.31).

CONCLUSION

In patients with diabetes admission, IV was associated with reduced risks of complications and mortality. Our study implicated the urgent need to promote influenza vaccination for this susceptible population with diabetes.

Preclinical and clinical developments for combination treatment of influenza

Antiviral drugs are an important measure of control for influenza in the population, particularly for those that are severely ill or hospitalised. The neuraminidase inhibitor (NAI) class of drugs, including oseltamivir, have been the standard of care (SOC) for severe influenza illness for many years. The approval of drugs with novel mechanisms of action, such as baloxavir marboxil, is important and broadens potential treatment options for combination therapy. The use of antiviral treatments in combination for influenza is of interest; one potential benefit of this treatment strategy is that the combination of drugs with different mechanisms of action may lower the selection of resistance due to treatment. In addition, combination therapy may become an important treatment option to improve patient outcomes in those with severe illness due to influenza or those that are immunocompromised. Clinical trials increasingly evaluate drug combinations in a range of patient cohorts. Here, we summarise preclinical and clinical advances in combination therapy for the treatment of influenza with reference to immunocompromised animal models and clinical data in hospitalised patient cohorts where available. There is a wide array of drug categories in development that have also been tested in combination. Therefore, in this review, we have included polymerase inhibitors, monoclonal antibodies (mAbs), host-targeted therapies, and adjunctive therapies. Combination treatment regimens should be carefully evaluated to determine whether they provide an added benefit relative to effectiveness of monotherapy and in a variety of patient cohorts, particularly, if there is a greater chance of an adverse outcome. Safe and effective treatment of influenza is important not only for seasonal influenza infection, but also if a pandemic strain was to emerge.

Clinical course of idiopathic inflammatory myopathies in COVID-19 pandemic: a single-center experience

Aim: To evaluate the clinical course of idiopathic inflammatory myopathy (IIM) patients in COVID-19 pandemic, and to assess the COVID-19 outcomes in infected IIM patients. Materials & methods: In this study, 39 patients were evaluated retrospectively. Myositis disease activity, myositis damage index, depression, fatigue, active medical treatment, drug compliance and SARS-CoV-2 PCR test results in COVID-19 pandemic were collected. Results: Fourteen of these patients (35%) were detected to have a positive SARS-CoV-2 PCR test. The demographic and clinical characteristics, active medical treatment, disease activity, depression and fatigue of the patients who had undergone or not SARS-CoV-2 were similar. Conclusion: Our results have shown that although prevalence of COVID-19 seems to be increased in IIM patients under immunosuppressive treatment, hospitalization rates were lower and no intensive care unit admissions or deaths were observed.

Effects and Interaction of Meteorological Parameters on Influenza Incidence During 2010-2019 in Lanzhou, China

Background

Influenza is a seasonal infectious disease, and meteorological parameters critically influence the incidence of influenza. However, the meteorological parameters linked to influenza occurrence in semi-arid areas are not studied in detail. This study aimed to clarify the impact of meteorological parameters on influenza incidence during 2010-2019 in Lanzhou. The results are expected to facilitate the optimization of influenza-related public health policies by the local healthcare departments.

Methods

Descriptive data related to influenza incidence and meteorology during 2010-2019 in Lanzhou were analyzed. The exposure-response relationship between the risk of influenza occurrence and meteorological parameters was explored according to the distributed lag no-linear model (DLNM) with Poisson distribution. The response surface model and stratified model were used to estimate the interactive effect between relative humidity (RH) and other meteorological parameters on influenza incidence.

Results

A total of 6701 cases of influenza were reported during 2010-2019. DLNM results showed that the risk of influenza would gradually increase as the weekly mean average ambient temperature (AT), RH, and absolute humidity (AH) decrease at lag 3 weeks when they were lower than 12.16°C, 51.38%, and 5.24 g/m³, respectively. The low Tem (at 5th percentile, P₅) had the greatest effect on influenza incidence; the greatest estimated relative risk (RR) was 4.54 (95%CI: 3.19-6.46) at cumulative lag 2 weeks. The largest estimates of RRs for low RH (P₅) and AH (P₅) were 4.81 (95%CI: 3.82-6.05) and 4.17 (95%CI: 3.30-5.28) at cumulative lag 3 weeks, respectively. An increase in AT by 1°C led to an estimates of percent change (95%CI) of 3.12% (-4.75% to -1.46%) decrease in the weekly influenza case counts in a low RH environment. In addition, RH showed significant interaction with AT and AP on influenza incidence but not with wind speed.

Conclusion

This study indicated that low AT, low humidity (RH and AH), and high air pressure (AP) increased the risk of influenza. Moreover, the interactive effect of low RH with low AT and high AP can aggravate the incidence of influenza.

An anti-influenza A virus microbial metabolite acts by degrading viral endonuclease PA

The emergence of new highly pathogenic and drug-resistant influenza strains urges the development of novel therapeutics for influenza A virus (IAV). Here, we report the discovery of an anti-IAV microbial metabolite called APL-16-5 that was originally isolated from the plant endophytic fungus Aspergillus sp. CPCC 400735. APL-16-5 binds to both the E3 ligase TRIM25 and IAV polymerase subunit PA, leading to TRIM25 ubiquitination of PA and subsequent degradation of PA in the proteasome. This mode of action conforms to that of a proteolysis targeting chimera which employs the cellular ubiquitin-proteasome machinery to chemically induce the degradation of target proteins. Importantly, APL-16-5 potently inhibits IAV and protects mice from lethal IAV infection. Therefore, we have identified a natural microbial metabolite with potent in vivo anti-IAV activity and the potential of becoming a new IAV therapeutic. The antiviral mechanism of APL-16-5 opens the possibility of improving its anti-IAV potency and specificity by adjusting its affinity for TRIM25 and viral PA protein through medicinal chemistry.

Factors associated with children's seasonal influenza diagnosis by their guardians: a prospective observational study in Japan

Introduction Children's influenza diagnosis by their guardians has been reported to be highly accurate, but clinical factors that improve the reliability of a guardian's diagnosis are unclear. Aim To determine the accuracy of guardians' influenza diagnosis of their children, investigate clinical factors that improve the diagnostic accuracy, and determine the additional clinical value of the guardian's diagnosis. Methods A prospective observational study was conducted at a primary care clinic in Japan from December 2017 to April 2019. Pre-examination checklists completed by guardians accompanying children aged Results A total of 112 patient pairs of child (median age, 6 years) and guardian (mother, 81.2%; father, 16.1%; grandmother, 1.8%; other, 0.9%) were included in the analysis. The AUC for guardians' influenza diagnosis was higher in mothers (0.72), as well as pairs with children with a history of influenza (0.72), guardians who were aware of the influenza epidemic (0.71), and unvaccinated children (0.76), than in other guardians. After multivariate analysis, the AUC increased significantly from 0.79 to 0.85. Discussion Guardians' influenza diagnosis for their children was highly accurate. We identified factors that improve the accuracy of the guardians' diagnosis and demonstrated that the guardians' diagnosis can support physicians' diagnostic accuracy.

Vaccinations in Patients with Rheumatic Disease: Consider Disease and Therapy

Patients with rheumatic diseases are susceptible to infections due to their underlying disease states as well as from immunosuppressive medications, highlighting the importance of vaccination, these same factors also pose challenges to vaccine efficacy, safety, and uptake. This article reviews the impact of immunosuppressive therapies and rheumatic disease on vaccine efficacy in this vulnerable patient population as well as discusses best practices.

Human seasonal influenza under COVID-19 and the potential consequences of influenza lineage elimination

Annual epidemics of seasonal influenza cause hundreds of thousands of deaths, high levels of morbidity, and substantial economic loss. Yet, global influenza circulation has been heavily suppressed by public health measures and travel restrictions since the onset of the COVID-19 pandemic. Notably, the influenza B/Yamagata lineage has not been conclusively detected since April 2020, and A(H3N2), A(H1N1), and B/Victoria viruses have since circulated with considerably less genetic diversity. Travel restrictions have largely confined regional outbreaks of A(H3N2) to South and Southeast Asia, B/Victoria to China, and A(H1N1) to West Africa. Seasonal influenza transmission lineages continue to perish globally, except in these select hotspots, which will likely seed future epidemics. Waning population immunity and sporadic case detection will further challenge influenza vaccine strain selection and epidemic control. We offer a perspective on the potential short- and long-term evolutionary dynamics of seasonal influenza and discuss potential consequences and mitigation strategies as global travel gradually returns to pre-pandemic levels.

Incidence, Disease Severity, and Follow-Up of Influenza A/A, A/B, and B/B Virus Dual Infections in Children: A Hospital-Based Digital Surveillance Program

Influenza virus (IV) coinfection, i.e., simultaneous infection with IV and other viruses, is a common occurrence in humans. However, little is known about the incidence and clinical impact of coinfection with two different IV subtypes or lineages (“dual infections”). We report the incidence, standardized disease severity, and follow-up of IV dual infections from a hospital-based digital surveillance cohort, comprising 6073 pediatric patients fulfilling pre-defined criteria of influenza-like illness in Berlin, Germany. All patients were tested for IV A/B by PCR, including subtypes/lineages. We assessed all patients at the bedside using the mobile ViVI ScoreApp, providing a validated disease severity score in real-time. IV-positive patients underwent follow-up assessments until resolution of symptoms. Overall, IV dual infections were rare (4/6073 cases; 0.07%, incidence 12/100,000 per year) but showed unusual and/or prolonged clinical presentations with slightly above-average disease severity. We observed viral rebound, serial infection, and B/Yamagata-B/Victoria dual infection. Digital tools, used for instant clinical assessments at the bedside, combined with baseline/follow-up virologic investigation, help identify coinfections in cases of prolonged and/or complicated course of illness. Infection with one IV does not necessarily prevent consecutive or simultaneous (co-/dual) infection, highlighting the importance of multivalent influenza vaccination and enhanced digital clinical and virological surveillance.

Influenza Vaccination in Systemic Lupus Erythematosus: Efficacy, Effectiveness, Safety, Utilization, and Barriers

Influenza increases morbidity and mortality in systemic lupus erythematosus (SLE) and lupus nephritis but is preventable through vaccination. This systematic review of PubMed, Embase, CENTRAL, WHO Clinical Trials, and ClinicalTrials.gov publications until August 2021 identified 45 reports (16,596 patients), including 8.5% with renal involvement or lupus nephritis: 9 studies (10,446 patients) on clinical effectiveness, 20 studies (1327 patients) on vaccine efficacy, 22 studies (1116 patients) on vaccine safety, 14 studies (4619 patients) on utilization rates, and 5 studies (3220 patients) on barriers. Pooled seroconversion rates ranged between 46% and 56%, while seroprotection rates ranged from 68% to 73% and were significantly associated with age and disease duration. Influenza infection was lower in vaccinated patients with systemic lupus erythematosus compared with unvaccinated patients. Disease activity scores did not change significantly after vaccination and reported flares were mild to moderate. Pooled current vaccination rate was 40.0% (95% confidence interval [CI]: 33.7%-46.5%) with significant heterogeneity and associated with the gross domestic product (P = .002) and disease duration (P = .001). Barriers to vaccination were the lack of doctor recommendation (57.4%) and concerns over the safety or efficacy of the vaccine (12.7%).

Inhibition of Influenza Virus Replication by Oseltamivir Derivatives

Characterized by the high morbidity and mortality and seasonal surge, the influenza virus (IV) remains a major public health challenge. Oseltamivir is commonly used as a first-line antiviral. As a neuraminidase inhibitor, it attenuates the penetration of viruses through the mucus on the respiratory tract and inhibits the release of virus progeny from infected cells. However, over the years, oseltamivir-resistant strains have been detected in the IV surveillance programs. Therefore, new antivirals that circumvent the resistant strains would be of great importance. In this study, two novel secondary amine derivatives of oseltamivir CUHK326 (6f) and CUHK392 (10i), which bear heteroaryl groups of M2-S31 proton channel inhibitors, were designed, synthesized and subjected to biological evaluation using plaque assay. Influenza A virus (A/Oklahoma/447/2008, H1N1), influenza B viruses (B/HongKong/CUHK33261/2012), an oseltamivir-resistant influenza A virus (A/HongKong/CUHK71923/2009, H1N1) and an oseltamivir-resistant influenza B virus (B/HongKong/CUHK33280/2012) were included in the antiviral effect assessment compared to oseltamivir carboxylate (OC). Both novel compounds significantly reduced the plaque size of seasonal IV A and B, and performed similarly to OC at their corresponding half-maximal inhibitory concentration (IC₅₀). CUHK392 (10i) functioned more effectively than CUHK326 (6f). More importantly, these compounds showed an inhibitory effect on the oseltamivir-resistant strain under 10 nM with selective index (SI) of >200.

Temporal and Gene Reassortment Analysis of Influenza C Virus Outbreaks in Hong Kong, SAR, China

From 2014 to week 07/2020 the Centre for Health Protection in Hong Kong conducted screening for influenza C virus (ICV). A retrospective analysis of ICV detections to week 26/2019 revealed persistent low-level circulation with outbreaks occurring biennially in the winters of 2015 to 2016 and 2017 to 2018 (R. S. Daniels et al., J Virol 94:e01051-20, 2020, https://doi.org/10.1128/JVI.01051-20). Here, we report on an outbreak occurring in 2019 to 2020, reinforcing the observation of biennial seasonality in Hong Kong. All three outbreaks occurred in similar time frames, were subsequently dwarfed by seasonal epidemics of influenza types A and B, and were caused by similar proportions of C/Kanagawa/1/76 (K)-lineage and C/São Paulo/378/82 S1- and S2-sublineage viruses. Ongoing genetic drift was observed in all genes, with some evidence of amino acid substitution in the hemagglutinin-esterase-fusion (HEF) glycoprotein possibly associated with antigenic drift. A total of 61 ICV genomes covering the three outbreaks were analyzed for reassortment, and 9 different reassortant constellations were identified, 1 K-lineage, 4 S1-sublineage, and 4 S2-sublineage, with 6 of these being identified first in the 2019-1920 outbreak (2 S2-lineage and 4 S1-lineage). The roles that virus interference/enhancement, ICV persistent infection, genome evolution, and reassortment might play in the observed seasonality of ICV in Hong Kong are discussed. IMPORTANCE Influenza C virus (ICV) infection of humans is common, with the great majority of people being infected during childhood, though reinfection can occur throughout life. While infection normally results in "cold-like" symptoms, severe disease cases have been reported in recent years. However, knowledge of ICV is limited due to poor systematic surveillance and an inability to propagate the virus in large amounts in the laboratory. Following recent systematic surveillance in Hong Kong SAR, China, and direct ICV gene sequencing from clinical specimens, a 2-year cycle of disease outbreaks (epidemics) has been identified, with gene mixing playing a significant role in ICV evolution. Studies like those reported here are key to developing an understanding of the impact of influenza C virus infection in humans, notably where comorbidities exist and severe respiratory disease can develop.

Clinical characteristics, risk factors and antiviral treatments of influenza in immunosuppressed inpatients in Beijing during the 2015-2020 influenza seasons

BACKGROUND

Compared with immunocompetent patients, immunosuppressed patients have higher morbidity and mortality, a longer duration of viral shedding, more frequent complications, and more antiviral resistance during influenza infections. However, few data on this population in China have been reported. We analysed the clinical characteristics, effects of antiviral therapy, and risk factors for admission to the intensive care unit (ICU) and death in this population after influenza infections and explored the influenza vaccination situation for this population.

METHODS

We analysed 111 immunosuppressed inpatients who were infected with influenza virus during the 2015-2020 influenza seasons. Medical data were collected through the electronic medical record system and analysed. Univariate analysis and multivariate logistics analysis were used to identify risk factors.

RESULTS

The most common cause of immunosuppression was malignancies being treated with chemotherapy (64.0%, 71/111), followed by haematopoietic stem cell transplantation (HSCT) (23.4%, 26/111). The most common presenting symptoms were fever and cough. Dyspnoea, gastrointestinal symptoms and altered mental status were more common in HSCT patients than in patients with immunosuppression due to other causes. Approximately 14.4% (16/111) of patients were admitted to the ICU, and 9.9% (11/111) of patients died. Combined and double doses of neuraminidase inhibitors did not significantly reduce the risk of admission to the ICU or death. Risk factors for admission to the ICU were dyspnoea, coinfection with other pathogens and no antiviral treatment within 48 h. The presence of dyspnoea and altered mental status were independently associated with death. Only 2.7% (3/111) of patients less than 12 months old had received a seasonal influenza vaccine.

CONCLUSION

Fever and other classic symptoms of influenza may be absent in immunosuppressed recipients, especially in HSCT patients. Conducting influenza virus detection at the first presentation seems to be a good choice for early diagnosis. Clinicians should pay extra attention to immunosuppressed patients with dyspnoea, altered mental status, coinfection with other pathogens and no antiviral treatment within 48 h because these patients have a high risk of severe illness. Inactivated influenza vaccines are recommended for immunosuppressed patients.

An Open-label Randomized Controlled Parallel-group Pilot Study Comparing the Immunogenicity of a Standard-, Double-, and Booster-dose Regimens of the 2014 Seasonal Trivalent Inactivated Influenza Vaccine in Kidney Transplant Recipients

BACKGROUND

Immunogenicity of influenza vaccine in transplant recipients is suboptimal and alternative vaccination regimens are necessary.

METHODS

We compared the immunogenicity of a standard-dose trivalent inactivated influenza vaccination (SDTIIV), double-dose trivalent inactivated influenza vaccination (DDTIIV), and booster-dose trivalent inactivated influenza vaccination (BDTIIV) of the 2014 seasonal trivalent inactivated influenza vaccine in kidney transplant recipients. We randomized 176 participants to SDTIIV (59), DDTIIV (59), and BDTIIV regimens (58). Antibody titers were determined by hemagglutination inhibition at enrollment and 21 d postvaccination. Seroprotection rates (SPRs), seroconversion rates (SCRs), and geometric mean ratios (GMRs) were analyzed separately for participants with low (<1:40) and high (≥1:40) prevaccination antibody titers.

RESULTS

Vaccination was confirmed for 172 participants. Immunogenicity analysis was done for 149 participants who provided postvaccination blood samples. In the subgroup with high prevaccination antibody titers, all vaccination regimens induced SPR > 70% to all antigens, but SCR and GMR were below the recommendations. In the subgroup with low prevaccination antibody titers, DDTIIV and BDTIIV regimens induced adequate SCR > 40% and GMR > 2.5 for all antigens, whereas SDTIIV achieved the same outcomes only for influenza B. SPRs were >70% only after DDTIIV (A/H1N1-77.8%) and BDTIIV (A/H3N2-77.8%). BDTIIV regimen independently increased seroprotection to A/H1N1 (PR = 2.58; P = 0.021) and A/H3N2 (PR = 2.21; P = 0.004), whereas DDTIIV independently increased seroprotection to A/H1N1 (PR = 2.59; P = 0.021).

CONCLUSIONS

Our results suggest that DDTIIV and BDTIIV regimens are more immunogenic than SDTIIV, indicating the need for head-to-head multicenter clinical trials to further evaluate their efficacy.

Changing Patterns of Disease Severity in Blastomyces dermatitidis Infection, Quebec, Canada

The increase in severe cases might be related to an increased number of immunosuppressed patients; climate change might also play a role.

This retrospective multicenter cohort study assessed temporal changes in the severity and mortality rate of blastomycosis in Quebec, Canada, and identified risk factors for death in patients with blastomycosis in 1988–2016. The primary outcome was 90-day all-cause deaths. Among 185 patients, 122 (66%) needed hospitalization and 30 (16%) died. We noted increases in the proportion of severe cases, in age at diagnosis and in the proportion of diabetic and immunocompromised patients over time. Independent risk factors for death were age (adjusted odds ratio [aOR] 1.04, 95% CI 1.00–1.07), immunosuppression (aOR 4.2, 95% CI 1.5–11.6), and involvement of >2 lung lobes (aOR 5.3, 95% CI 1.9–14.3). There was no association between the Blastomyces genotype group and all-cause mortality. The proportion of severe cases of blastomycosis has increased in Quebec over the past 30 years, partially explained by the higher number of immunosuppressed patients.

Impact of COVID-19 on Pediatric Immunocompromised Patients

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Simulating influenza epidemics with waning vaccine immunity

Observational studies indicate that vaccine-induced immunity can decline over time. However, few researchers have incorporated this kind of waning effect into their virus spread models. In this study, we simulate an influenza epidemic that considers the effects of waning immunity by fitting epidemiological models to CDC secondary historical data aggregated on a weekly basis, and derive the transmission rates at which susceptible individuals become infected over the course of the influenza season. Using a system of differential equations, we define four groups of individuals in a population: susceptible, vaccinated, infected, and recovered. We show that a larger number of initially infected individuals might not only bring the influenza season to an end sooner but also reduce the epidemic size. Moreover, any influenza virus that entails a faster recovery rate does not necessarily lead to a smaller epidemic size. We illustrate how simulation helps in understanding the effects of influenza epidemiological model in the presence of waning influenza vaccine immunity.

Understanding the Host in the Management of Pneumonia. An Official American Thoracic Society Workshop Report

Pneumonia causes a significant burden of disease worldwide. Although all populations are at risk of pneumonia, those at extremes of age and those with immunosuppressive disorders, underlying respiratory disease, and critical illness are particularly vulnerable. Although clinical practice guidelines addressing the management and treatment of pneumonia exist, few of the supporting studies focus on the crucial contributions of the host in pneumonia pathogenesis and recovery. Such essential considerations include the host risk factors that lead to susceptibility to lung infections; biomarkers reflecting the host response and the means to pursue host-directed pneumonia therapy; systemic effects of pneumonia on the host; and long-term health outcomes after pneumonia. To address these gaps, the Pneumonia Working Group of the Assembly on Pulmonary Infection and Tuberculosis led a workshop held at the American Thoracic Society meeting in May 2018 with overarching objectives to foster attention, stimulate research, and promote funding for short-term and long-term investigations into the host contributions to pneumonia. The workshop involved participants from various disciplines with expertise in lung infection, pneumonia, sepsis, immunocompromised patients, translational biology, data science, genomics, systems biology, and clinical trials. This workshop report summarizes the presentations and discussions and important recommendations for future clinical pneumonia studies. These recommendations include establishing consensus disease and outcome definitions, improved phenotyping, development of clinical study networks, standardized data and biospecimen collection and protocols, and development of innovative trial designs.

Review of Influenza Virus Vaccines: The Qualitative Nature of Immune Responses to Infection and Vaccination Is a Critical Consideration

Influenza viruses have affected the world for over a century, causing multiple pandemics. Throughout the years, many prophylactic vaccines have been developed for influenza; however, these viruses are still a global issue and take many lives. In this paper, we review influenza viruses, associated immunological mechanisms, current influenza vaccine platforms, and influenza infection, in the context of immunocompromised populations. This review focuses on the qualitative nature of immune responses against influenza viruses, with an emphasis on trained immunity and an assessment of the characteristics of the host–pathogen that compromise the effectiveness of immunization. We also highlight innovative immunological concepts that are important considerations for the development of the next generation of vaccines against influenza viruses.

The severity and risk factors for mortality in immunocompromised adult patients hospitalized with influenza-related pneumonia

Objective

To explore disease severity and risk factors for 30-day mortality of adult immunocompromised (IC) patients hospitalized with influenza-related pneumonia (Flu-p).

Method

A total of 122 IC and 1191 immunocompetent patients hospitalized with Flu-p from January 2012 to December 2018 were recruited retrospectively from five teaching hospitals in China.

Results

After controlling for confounders, multivariate logistic regression analysis showed that immunosuppression was associated with increased risks for invasive ventilation [odds ratio: (OR) 2.475, 95% confidence interval (CI): 1.511–4.053, p < 0.001], admittance to the intensive care unit (OR: 3.247, 95% CI 2.064–5.106, p < 0.001), and 30-day mortality (OR: 3.206, 95% CI 1.926–5.335, p < 0.001) in patients with Flu-p. Another multivariate logistic regression model revealed that baseline lymphocyte counts (OR: 0.993, 95% CI 0.990–0.996, p < 0.001), coinfection (OR: 5.450, 95% CI 1.638–18.167, p = 0.006), early neuraminidase inhibitor therapy (OR 0.401, 95% CI 0.127–0.878, p = 0.001), and systemic corticosteroid use at admission (OR: 6.414, 95% CI 1.348–30.512, p = 0.020) were independently related to 30-day mortality in IC patients with Flu-p. Based on analysis of the receiver operating characteristic curve (ROC), the optimal cutoff for lymphocyte counts was 0.6 × 10⁹/L [area under the ROC (AUROC) = 0.824, 95% CI 0.744—0.887], sensitivity: 97.8%, specificity: 73.7%].

Conclusions

IC conditions are associated with more severe outcomes in patients with Flu-p. The predictors for mortality that we identified may be valuable for the management of Flu-p among IC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12941-021-00462-7.

Characteristics of viral pneumonia in non-HIV immunocompromised and immunocompetent patients: a retrospective cohort study

BACKGROUND

Concerning viral pneumonia, few large-scale comparative studies have been published describing non-HIV immunocompromised and immunocompetent patients, but the epidemiological characteristics of different viruses or underlying diseases in immunocompromised hosts are lacking.

METHODS

We retrospectively recruited patients hospitalised with viral pneumonia from six academic hospitals in China between August 2016 and December 2019. We measured the prevalence of comorbidities, coinfections, nosocomial infections, and in-hospital mortalities.

RESULTS

Of the 806 patients, 370 were immunocompromised and 436 were immunocompetent. The disease severity and in-hospital mortality of immunocompromised patients were higher than those of immunocompetent patients. During the influenza season, an increased number of cases of influenza virus (IFV) infection were found in the immunocompromised group, followed by cases of cytomegalovirus (CMV) and respiratory syncytial virus (RSV) infection. During the non-influenza season, CMV was the main virus detected in the immunocompromised group, while RSV, adenovirus (AdV), parainfluenza virus (PIV), and rhinovirus (HRV) were the main viruses detected in the immunocompetent group. Pneumonia caused by Pneumocystis jirovecii (22.4%), Aspergillus spp. (14.1%), and bacteria (13.8%) were the most frequently observed coinfections in immunocompromised patients but not in immunocompetent patients (Aspergillus spp. [10.8%], bacteria [7.1%], and Mycoplasma spp. [5.3%]). CMV infection and infection with two-or-more viruses were associated with a higher in-hospital mortality rate than non-IFV infection. However, patients with IFV and non-IFV infection in immunocompromised patients had similar disease severity and prognosis.

CONCLUSIONS

Immunocompromised patients have a high frequency of coinfections, and a higher mortality rate was observed among those infected with CMV and two-or-more viruses. In addition, patients with IFV and non-IFV infection in immunocompromised patients had similar same disease severity and prognosis. The type of viral infection varied with seasons.

In-hospital mortality among immunosuppressed patients with COVID-19: Analysis from a national cohort in Spain

BACKGROUND

Whether immunosuppressed (IS) patients have a worse prognosis of COVID-19 compared to non-IS patients is not known. The aim of this study was to evaluate the clinical characteristics and outcome of IS patients hospitalized with COVID-19 compared to non-IS patients.

METHODS

We designed a retrospective cohort study. We included all patients hospitalized with laboratory-confirmed COVID-19 from the SEMI-COVID-19 Registry, a large multicentre national cohort in Spain, from March 27th until June 19th, 2020. We used multivariable logistic regression to assess the adjusted odds ratios (aOR) of in-hospital death among IS compared to non-IS patients.

RESULTS

Among 13 206 included patients, 2 111 (16.0%) were IS. A total of 166 (1.3%) patients had solid organ (SO) transplant, 1081 (8.2%) had SO neoplasia, 332 (2.5%) had hematologic neoplasia, and 570 (4.3%), 183 (1.4%) and 394 (3.0%) were receiving systemic steroids, biological treatments, and immunosuppressors, respectively. Compared to non-IS patients, the aOR (95% CI) for in-hospital death was 1.60 (1.43-1.79) for all IS patients, 1.39 (1.18-1.63) for patients with SO cancer, 2.31 (1.76-3.03) for patients with haematological cancer and 3.12 (2.23-4.36) for patients with SO transplant. The aOR (95% CI) for death for patients who were receiving systemic steroids, biological treatments and immunosuppressors compared to non-IS patients were 2.16 (1.80-2.61), 1.97 (1.33-2.91) and 2.06 (1.64-2.60), respectively. IS patients had a higher odds than non-IS patients of in-hospital acute respiratory distress syndrome, heart failure, myocarditis, thromboembolic disease and multiorgan failure.

CONCLUSIONS

IS patients hospitalized with COVID-19 have a higher odds of in-hospital complications and death compared to non-IS patients.