Influenza Co-infection Research Articles

INVASIVE TRICHOSPORON INFECTION IN A SARS-COV-2 AND INFLUENZA COINFECTED PATIENT: A CASE REPORT

Trichosporon species can cause systemic or mucosal-associated or superficial infections, including white piedra, as well as invasive fungal infections. They can be an opportunistic cause of invasive infection, especially in patients with hematological malignancies and solid organ tumors or immunosuppressed transplant recipients. There has been an increase in invasive infections due to Trichosporon species in recent years. Treatment of patients with trichosporonosis poses a problem due to limited data regarding the antifungal agents used. In this article, we present a case that resulted in death as a result of invasive trichosporonosis infection that developed after a long stay in intensive care due to co-infection of COVID-19 and influenza.

A case of severe COVID-19 and influenza co-infection

Aim. To analyze a case of severe COVID-19 and influenza co-infection in a 48-year-old female patient. Materials and methods. The clinical course, specifics of diagnosis and therapy of the 48-year-old patient S., who was treated for severe co-infection of COVID-19 and influenza at Municipal non-profit Enterprise “Regional Infectious Clinical Hospital” Zaporizhzhіa Regional Council from 29.01.2023 to 17.02.2023, were analyzed. The diagnosis of COVID-19 was confirmed by the detection of SARS-CoV-2 Ag in nasopharyngeal swabs by the immunochromatographic method, and the diagnosis of influenza – by the influenza A viral RNA detection by the polymerase chain reaction method. Current regulatory documents were used when examining and treating the patient. Results. It has been recognized that the unvaccinated 48-year-old female patient was at a risk group due to comorbid pathology (stage 2 hypertension, type 2 diabetes mellitus, grade 2 obesity) developed a severe course of COVID-19 and influenza type A co-infection. The course of co-infection was complicated by severe acute respiratory distress syndrome already on the 6th day of the disease. The diagnosis of COVID-19 was confirmed by a rapid SARS-CoV-2 antigen test. Treatment for COVID-19 was started immediately with the use of remdesivir, dexamethasone, and anticoagulants. However, despite the patient was given the treatment, his condition worsened due to the rapid progression of acute respiratory failure. The presence of clear clinical and laboratory signs of “cytokine storm” required the use of tocilizumab on the 7th day of the disease. Oseltamivir was commenced after receiving laboratory confirmation of influenza A by the PCR method on the 8th day of the disease. A complete etiologic interpretation of the diagnosis made it possible to prescribe a combination antiviral treatment which coupled with the timely additional initiation of tocilizumab, allowed obtaining certain positive dynamics after only five days of treatment with further improvement of the patient’s condition. Conclusions. Our clinical observation has demonstrated the severe course of COVID-19 and influenza co-infection in the unvaccinated high-risk 48-year-old female patient due to the presence of comorbid pathology. The complete etiologic interpretation of the co-infection has made it possible to prescribe the combination antiviral treatment, which coupled with the additional correction of the immunotropic treatment has enabled to obtain the positive dynamics after only 5 days with further improvement of the patient’s condition

Ferrets as a Mammalian Model to Study Influenza Virus-Bacteria Interactions.

Ferrets represent an invaluable model for the study of influenza virus pathogenicity and transmissibility. Ferrets are also employed for the study of bacterial pathogens that naturally infect humans at different anatomical sites. While viral and bacterial infection studies in isolation using animal models are important for furthering our understanding of pathogen biology and developing improved therapeutics, it is also critical to extend our knowledge to pathogen coinfections in vivo, to more closely examine interkingdom dynamics that may contribute to overall disease outcomes. We discuss how ferrets have been employed to study a diverse range of both influenza viruses and bacterial species and summarize key studies that have utilized the ferret model for primary influenza virus challenge followed by secondary bacterial infection. These copathogenesis studies have provided critical insight into the dynamic interplay between these pathogens, underscoring the utility of ferrets as a model system for investigating influenza virus-bacteria interactions.

Prevalence and associated outcomes of coinfection between SARS-CoV-2 and influenza: a systematic review and meta-analysis

ObjectivesTo estimate the prevalence of influenza coinfection in COVID-19 patients and investigate its association with severe clinical outcomes. MethodsWe systematically searched the Web of Science, PubMed, Scopus, Embase, The Cochrane Library, and CNKI for studies published between January 01, 2020, and May 31, 2023. Meta-analysis was performed to estimate the pooled prevalence of coinfection and the impact on clinical outcomes. Systematic review registered in PROSPERO (CRD42023423113). ResultsA total of 95 studies involving 62,107 COVID-19 patients were included. The pooled prevalence of coinfection with influenza virus was 2.45% (95% confidence interval [CI]: 1.67-3.58%), with a high proportion of influenza A. Compared with mono-infected patients (COVID-19 only), the odds ratio (OR) for severe outcomes (including intensive care unit admission [OR = 2.20, 95% CI: 1.68-2.87, P < 0.001], mechanical ventilation support [OR = 2.73, 95% CI: 1.46-5.10, P = 0.002], and mortality [OR = 2.92, 95% CI: 1.16-7.30, P = 0.022]) was significantly higher among patients coinfected influenza A. ConclusionAlthough the prevalence of coinfection is low, coinfected patients are at higher risk of severe outcomes. Enhanced identification of both viruses, as well as individualized treatment protocols for coinfection, are recommended to reduce the occurrence of serious disease outcomes in the future.

A non-linear differential equation model of COVID-19 and seasonal influenza co-infection dynamics under vaccination strategy and immunity waning

This study presents a mathematical model of the transmission dynamics of COVID-19 and influenza co-infection. The potential impacts of the influenza vaccine only on the co-infection dynamics and the potential impacts of both vaccines on the co-infection dynamics are thoroughly studied. The basic reproduction number for the two diseases using the next-generation matrix approach and the stability of the sub-model is examined. The model assessed the scenario whereby both diseases’ waning immunity occurs concurrently to check the epidemic peaks. The numerical simulation results show that the diseases would continue to be endemic in the population if the immunity waning rates increase. The epidemic peak can be reduced by increasing vaccination and vaccine efficacy rates. The results show that the COVID-19 contact rate significantly increases the epidemic level more than the co-infection contact rate. A similar result was obtained when it was observed that the COVID-19 post-recovery waning rate has more significant effects on the epidemic peak than the co-infection post-recovery waning rate. A possible reason for this counter-intuitive occurrence is that two infections cannot have the same viral load nor the same within-host competitiveness. This means an infectious co-infected person will transmit the infection with the highest within-host competitiveness. Here, it is suspected that COVID-19 has a within-host competitive advantage over influenza in the co-dynamics.

NEDD4 Regulated Pyroptosis Occurred from Co-infection between Influenza A Virus and Streptococcus pneumoniae.

Co-infection of respiratory tract viruses and bacteria often result in excess mortality, especially pneumonia caused by influenza viruses and Streptococcus pneumoniae. However, the synergistic mechanisms remain poorly understood. Therefore, it is necessary to develop a clearer understanding of the molecular basis of the interaction between influenza virus and Streptococcus pneumonia. Here, we developed the BALB/c mouse model and the A549 cell model to investigate inflammation and pyroptotic cell death during co-infection. Co-infection significantly activated the NLRP3 inflammasome and induced pyroptotic cell death, correlated with excess mortality. The E3 ubiquitin ligase NEDD4 interacted with both NLRP3 and GSDMD, the executor of pyroptosis. NEDD4 negatively regulated NLRP3 while positively regulating GSDMD, thereby modulating inflammation and pyroptotic cell death. Our findings suggest that NEDD4 may play a crucial role in regulating the GSDMD-mediated pyroptosis signaling pathway. Targeting NEDD4 represents a promising approach to mitigate excess mortality during influenza pandemics by suppressing synergistic inflammation during co-infection of influenza A virus and Streptococcus pneumoniae.

Clinical and Virologic Impacts of Respiratory Viral Co-infections in Children With Influenza.

Advances in multiplex polymerase chain reaction (PCR) methods have enabled the simultaneous detection of multiple respiratory viruses. We aimed to estimate the clinical and virologic impacts of influenza and other respiratory virus co-infection in children. We enrolled 38 and 35 children diagnosed with influenza and treated with baloxavir marboxil (baloxavir) and oseltamivir, respectively. We performed quantitative reverse transcription-PCR to detect and measure the levels of noninfluenza viruses from 3 nasopharyngeal swab samples collected before and on days 3 and 5 after the initial antiviral dose. We assessed patients' clinical information using questionnaires. One or more respiratory viruses other than influenza virus were detected in 26 (35.6%) of 73 children before antiviral treatment. The influenza virus load and clinical characteristics on the day of influenza onset were similar between children with and without virus co-infections. Of the 26 and 32 children without the emergence of the reduced baloxavir and oseltamivir susceptible variants after treatment, 8 (30.8%) and 7 (21.9%) children were dually co-infected with human rhinovirus only, respectively. The level of human rhinovirus RNA on day 0 in these children was less than -3 log 10 that of influenza virus RNA, and the human rhinovirus co-infection had no impact on the disease course either clinically or virologically. When multiple respiratory viruses are detected in the same patient, it is necessary to assess clinical symptoms as well as the levels of detected viruses to determine which virus contributes to the development of illness.

A multiscale mechanistic model of human dendritic cells for in-silico investigation of immune responses and novel therapeutics discovery.

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) with the unique ability to mediate inflammatory responses of the immune system. Given the critical role of DCs in shaping immunity, they present an attractive avenue as a therapeutic target to program the immune system and reverse immune disease disorders. To ensure appropriate immune response, DCs utilize intricate and complex molecular and cellular interactions that converge into a seamless phenotype. Computational models open novel frontiers in research by integrating large-scale interaction to interrogate the influence of complex biological behavior across scales. The ability to model large biological networks will likely pave the way to understanding any complex system in more approachable ways. We developed a logical and predictive model of DC function that integrates the heterogeneity of DCs population, APC function, and cell-cell interaction, spanning molecular to population levels. Our logical model consists of 281 components that connect environmental stimuli with various layers of the cell compartments, including the plasma membrane, cytoplasm, and nucleus to represent the dynamic processes within and outside the DC, such as signaling pathways and cell-cell interactions. We also provided three sample use cases to apply the model in the context of studying cell dynamics and disease environments. First, we characterized the DC response to Sars-CoV-2 and influenza co-infection by in-silico experiments and analyzed the activity level of 107 molecules that play a role in this co-infection. The second example presents simulations to predict the crosstalk between DCs and T cells in a cancer microenvironment. Finally, for the third example, we used the Kyoto Encyclopedia of Genes and Genomes enrichment analysis against the model's components to identify 45 diseases and 24 molecular pathways that the DC model can address. This study presents a resource to decode the complex dynamics underlying DC-derived APC communication and provides a platform for researchers to perform in-silico experiments on human DC for vaccine design, drug discovery, and immunotherapies.

Dynamic Behaviors of a COVID-19 and Influenza Co-Infection Model with Time Delays and Humoral Immunity

Co-infections with respiratory viruses were reported in hospitalized patients in several cases. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A virus (IAV) are two respiratory viruses and are similar in terms of their seasonal occurrence, clinical manifestations, transmission routes, and related immune responses. SARS-CoV-2 is the cause of coronavirus disease 2019 (COVID-19). In this paper, we study the dynamic behaviors of an influenza and COVID-19 co-infection model in vivo. The role of humoral (antibody) immunity in controlling the co-infection is modeled. The model considers the interactions among uninfected epithelial cells (ECs), SARS-CoV-2-infected ECs, IAV-infected ECs, SARS-CoV-2 particles, IAV particles, SARS-CoV-2 antibodies, and IAV antibodies. The model is given by a system of delayed ordinary differential equations (DODEs), which include four time delays: (i) a delay in the SARS-CoV-2 infection of ECs, (ii) a delay in the IAV infection of ECs, (iii) a maturation delay of newly released SARS-CoV-2 virions, and (iv) a maturation delay of newly released IAV virions. We establish the non-negativity and boundedness of the solutions. We examine the existence and stability of all equilibria. The Lyapunov method is used to prove the global stability of all equilibria. The theoretical results are supported by performing numerical simulations. We discuss the effects of antiviral drugs and time delays on the dynamics of influenza and COVID-19 co-infection. It is noted that increasing the delay length has a similar influence to that of antiviral therapies in eradicating co-infection from the body.

Adapting an integrated acute respiratory infections sentinel surveillance to the COVID-19 pandemic requirements, Egypt, 2020–2022

ObjectivesIn Egypt, an integrated surveillance for acute respiratory infections (ARIs) was established in 2016 to identify the causes of ARIs. The surveillance system includes 19 governmental hospitals. In response to the coronavirus disease 2019 (COVID-19) pandemic, the World Health Organisation (WHO) requested surveillance adaptation to address the emerging challenges. This study aims to describe the experience in Egypt of adapting ARI surveillance to the COVID-19 pandemic. MethodsWHO case definitions were used to identify patients with ARIs. Nasopharyngeal/oropharyngeal swabs were collected for SARS-CoV-2 and influenza testing. Demographic and clinical information were obtained by interviewing patients at the hospitals. During the COVID-19 pandemic, the first two outpatients daily and every fifth admitted patient were enrolled in the study. To determine the status of ARIs in Egypt during the pandemic, patient demographic, clinical and laboratory data from 2020 to 2022 were obtained and descriptive analyses were performed. ResultsOverall, 18,160 patients were enrolled in the study, including 7923 (43.6%) seen at outpatient clinics and 10,237 (56.4%) inpatients. Of the study participants, 6453 (35.5%) tested positive for ARIs, including 5620 (87.1%) for SARS-CoV-2, 781 (12.1%) for influenza and 52 (0.8%) for SARS-CoV-2/influenza coinfection. SARS-CoV-2 was the cause for 95.3% of admitted patients and 65.4% of outpatients. Influenza subtypes included A/H3 (55.7%), Influenza-B (29.1%) and H1/pdm09 (14.2%). Compared with influenza, SARS-CoV-2 tended to infect the elderly, in warm weather and in urban governorates, and resulted in more hospitalisations, longer hospital stays and higher case fatalities (16.3% vs 6.6%, p < 0.001). ConclusionsARI surveillance in Egypt was successfully adapted to the COVID-19 pandemic and effectively described the clinical characteristics and severity of circulating viruses. Surveillance reported the re-emergence of influenza with a severe course and high fatality. Surveillance is essential for monitoring the activity of respiratory viruses with the aim of guiding clinical management, including preventative and control measures.

Prevalence of SARS-CoV-2 and Influenza Coinfection and Clinical Characteristics Among Children and Adolescents Aged

The 2022-23 influenza season shows an early rise in pediatric influenza-associated hospitalizations (1). SARS-CoV-2 viruses also continue to circulate (2). The current influenza season is the first with substantial co-circulation of influenza viruses and SARS-CoV-2 (3). Although both seasonal influenza viruses and SARS-CoV-2 can contribute to substantial pediatric morbidity (3-5), whether coinfection increases disease severity compared with that associated with infection with one virus alone is unknown. This report describes characteristics and prevalence of laboratory-confirmed influenza virus and SARS-CoV-2 coinfections among patients aged <18 years who had been hospitalized or died with influenza as reported to three CDC surveillance platforms during the 2021-22 influenza season. Data from two Respiratory Virus Hospitalizations Surveillance Network (RESP-NET) platforms (October 1, 2021-April 30, 2022),§ and notifiable pediatric deaths associated¶ with influenza virus and SARS-CoV-2 coinfection (October 3, 2021-October 1, 2022)** were analyzed. SARS-CoV-2 coinfections occurred in 6% (32 of 575) of pediatric influenza-associated hospitalizations and in 16% (seven of 44) of pediatric influenza-associated deaths. Compared with patients without coinfection, a higher proportion of those hospitalized with coinfection received invasive mechanical ventilation (4% versus 13%; p = 0.03) and bilevel positive airway pressure or continuous positive airway pressure (BiPAP/CPAP) (6% versus 16%; p = 0.05). Among seven coinfected patients who died, none had completed influenza vaccination, and only one received influenza antivirals.†† To help prevent severe outcomes, clinicians should follow recommended respiratory virus testing algorithms to guide treatment decisions and consider early antiviral treatment initiation for pediatric patients with suspected or confirmed influenza, including those with SARS-CoV-2 coinfection who are hospitalized or at increased risk for severe illness. The public and parents should adopt prevention strategies including considering wearing well-fitted, high-quality masks when respiratory virus circulation is high and staying up-to-date with recommended influenza and COVID-19 vaccinations for persons aged ≥6 months.

COVID-19 and Influenza Coinfection Outcomes among Hospitalized Patients in the United States: A Propensity Matched Analysis of National Inpatient Sample.

This study aims to provide comparative data on clinical features and in-hospital outcomes among U.S. adults admitted to the hospital with COVID-19 and influenza infection using a nationwide inpatient sample (N.I.S.) data 2020. Data were collected on patient characteristics and in-hospital outcomes, including patient's age, race, sex, insurance status, median income, length of stay, mortality, hospitalization cost, comorbidities, mechanical ventilation, and vasopressor support. Additional analysis was performed using propensity matching. In propensity-matched cohort analysis, influenza-positive (and COVID-positive) patients had higher mean hospitalization cost (USD 129,742 vs. USD 68,878, p = 0.04) and total length of stay (9.9 days vs. 8.2 days, p = 0.01), higher odds of needing mechanical ventilation (OR 2.01, 95% CI 1.19-3.39), and higher in-hospital mortality (OR 2.09, 95% CI 1.03-4.24) relative to the COVID-positive and influenza-negative cohort. In conclusion, COVID-positive and influenza-negative patients had lower hospital charges, shorter hospital stays, and overall lower mortality, thereby supporting the use of the influenza vaccine in COVID-positive patients.

NLRP6 Induces Lung Injury and Inflammation Early in Brucella and Influenza Coinfection.

(1) Background: With the resurgence of brucellosis epidemics in China in recent years, the chances of a brucella coinfection with other common respiratory pathogens, such as the influenza virus, have increased dramatically. However, little is known about the pathogenicity or the mechanisms of brucella and influenza coinfections. (2) Methods: To clarify the interventions in the early stages of lung damage due to brucella and influenza coinfections, we evaluated the effect of the coinfection on disease progression and mortality using a coinfection model in WT mice and NLRP6-/- mice, and we verified the function of NLRP6 in infection and proinflammation. (3) Results: The coinfection induced significant respiratory symptoms, weight loss, and a high mortality rate in WT mice. Influenza in the coinfection group significantly increased brucella proliferation in a synergistic manner. Meanwhile, a histological examination showed severe lung tissue destruction and excessive inflammatory responses in coinfected WT animals, and the expression of NLRP6 and IL-18 was dramatically increased in the lung tissues. Furthermore, NLRP6 deletion attenuated lung injuries and inflammation, a reduced bacterial load, and decreased IL-18 protein expression. (4) Conclusions: Our findings indicated that NLRP6 plays a critical role and might be a promising potential therapeutic target for brucella-influenza coinfections.

Features of the course of influenza and its co-infection in children at the present stage

Influenza is an acute respiratory infection, mainly affecting the respiratory tract (often the trachea), with a tendency to develop symptoms rapidly and in most cases not requiring hospitalization. All acute respiratory infections are non-specific, with symptoms of intoxication, catarrhal symptoms (nasal congestion, rhinorrhoea, sore throat or pharyngeal discomfort), fever and cough. Improvement and widespread implementation of molecular methods to identify respiratory pathogens has led to the establishment of a higher frequency of co-infections. A literature review of the frequency of influenza co-infections is presented. Clinical cases of monoinfluenza and co-infections of influenza and respiratory syncytial infection are described, demonstrating the antagonistic effect of the two viruses on the course of the disease. In the first case, the patient, 1 year 1 month old, was hospitalised with a fever of 39 ºC in a moderate condition. A nasopharyngeal swab showed RNA of influenza A virus by PCR and was diagnosed with influenza. In the second case, the patient, 2 years old, at the beginning of the disease complained of an increase in body temperature to 38.7 ºC, cough, and difficulty in nasal breathing. On admission, the patient was in moderate condition with a body temperature of 36.6 ºC, clear consciousness and well-being. On auscultation, breathing in the lungs was rigid, single moist rales, scattered on both sides. A nasopharyngeal swab showed RNA of influenza A virus and respiratory syncytial virus by PCR. A viral acute respiratory infection of combined etiology and acute bronchitis was diagnosed. In the third case, a 14-year-old patient presented with complaints of fever up to 39 ºC, headache, weakness, muscle pain, dry cough. The condition was of moderate severity. The diagnosis of influenza A was confirmed by a rapid test for influenza A/B/C. In the treatment and prevention of both monoinfection and co-infections of influenza and other viruses, these clinical examples demonstrate the effectiveness of oseltamivir. These clinical examples highlight some key parameters: respiratory co-infections change the typical clinical picture of the disease, making it difficult to clinically diagnose the infection, highlighting laboratory diagnosis, which in turn facilitates rapid verification of the diagnosis and timely prescription of adequate therapy.

COVID-19 and Coinfections: A Serious Health Threat Requires Combination of Diagnosis and Therapy.

Since the advent of the COVID-19 pandemic in 2019, a mammoth research activity targeting the etiological features of COVID-19 has commenced. Many aspects of the disease have been studied, and various others are under consideration. The secondary microbial coinfections with COVID-19 have generated some serious concerns across the globe. This review mainly focuses on the notable secondary coinfections. The coinfection of influenza, tuberculosis, and typhoid may mimic the original COVID-19 symptoms. Physicians and clinicians must focus on the secondary coinfections which may aggravate the disease progression towards acute respiratory disorder syndrome (ARDS). Diagnostic strategies must also be redefined to determine the actual underlying secondary coinfection. There is a need for combination therapy and diagnostic approaches to minimize the risks associated with the COVID-19 pandemic effectively.

Incidence, risk factors, and whole-genome sequence of SARs-CoV-2 and influenza virus among the Egyptian pilgrims returning from Umrah mass gathering in Saudi Arabia, April-May 2022

BackgroundRamadan Umrah is the second largest Islamic pilgrimage with 2.75 million pilgrims allowed in 2022. This report presents the results of a survey among Egyptian pilgrims returning from Ramadan Umrah to monitor SARS-CoV-2 and influenza activity and identify prevalent SARS-CoV-2 variants after this mass gathering. MethodsCross‐sectional survey conducted at Cairo airport from 30th April 2022–5 th May 2022. Pilgrims were invited to participate voluntarily. After consenting, participants interviewed using questionnaire including demographics, health status, and vaccination information and asked to provide NP/OP swabs for SARS-CoV-2 and influenza testing by RT-PCR. Whole-genome sequencing performed for 29 SARS-CoV-2 isolates. Incidence calculated, descriptive data analysis performed, and SARS-CoV-2 patients were compared to negatively tested participants using chi2 and p value< 0.05. ResultsOverall, 1003 subjects participated, their mean age 50.9 ± 13 years, 594 (59.2%) were males. Of them, 76(7.6%) tested positive including 67(6.7%) SARS-CoV-2, 7(0.7%) influenza and 2(0.2%) SARS-CoV-2/influenza coinfection. Omicron sublineage BA.2 was the prevalent variant with no difference in severity identified between BA.1 and BA.2. No difference was identified between COVID-19 incidence among receivers of different vaccine types or between fully vaccinated and booster dose receivers. ConclusionsSurvey indicated a low incidence of SARs-CoV-2 and influenza among Egyptian pilgrims returning from Ramadan Umrah. Patients had mild or no symptoms with no hospitalization or deaths reported. Full vaccination and booster doses of COVID-19 vaccines proved equally effective. Enhancing COVID-19 and influenza vaccination before mass gatherings and close monitoring of respiratory viruses among pilgrims returning from Hajj and Umrah are crucial for outbreak early detection and mitigation.

A combination vaccine against SARS-CoV-2 and H1N1 influenza based on receptor binding domain trimerized by six-helix bundle fusion core.

SummaryBackgroundIncreasing severe morbidity and mortality by simultaneous or sequential infections with SARS-CoV-2 and influenza A viruses (IAV), especially in the elderly and obese patients, highlight the urgency of developing a combination vaccine against COVID-19 and influenza.MethodsSelf-assembling SARS-CoV-2 RBD-trimer and Influenza H1N1 HA1-trimer antigens were constructed, upon the stable fusion core in post-fusion conformation. Immunogenicity of SARS-CoV-2 RBD-trimer vaccine and H1N1 HA1-trimer antigens candidates were evaluated in mice. Protection efficacy of a combination vaccine candidate against SARS-CoV-2 and IAV challenge was identified using the K18-hACE2 mouse model.FindingsBoth the resultant RBD-trimer for SARS-CoV-2 and HA1-trimer for H1N1 influenza fully exposed receptor-binding motifs (RBM) or receptor-binding site (RBS). Two-dose RBD-trimer induced significantly higher binding and neutralizing antibody titers, and also a strong Th1/Th2 balanced cellular immune response in mice. Similarly, the HA1-trimer vaccine was confirmed to exhibit potent immunogenicity in mice. A combination vaccine candidate, composed of RBD-trimer and HA1-trimer, afforded high protection efficacy in mouse models against stringent lethal SARS-CoV-2 and homogenous H1N1 influenza co-infection, characterized by 100% survival rate.InterpretationOur results represent a proof of concept for a combined vaccine candidate based on trimerized receptor binding domain against co-epidemics of COVID-19 and influenza.FundingThis project was funded by the Strategic Priority Research Program of CAS (XDB29040201), the National Natural Science Foundation of China (81830050, 81901680, and 32070569) and China Postdoctoral Science Foundation (2021M703450).

SARS-CoV-2 and influenza co-infection: A cross-sectional study in central Missouri during the 2021–2022 influenza season

As SARS-CoV-2 and influenza viruses co-circulate, co-infections with these viruses generate an increasing concern to public health. To evaluate the prevalence and clinical impacts of SARS-CoV-2 and influenza A virus co-infections during the 2021–2022 influenza season, SARS-CoV-2-positive samples from 462 individuals were collected from October 2021 to January 2022. Of these individuals, 152 tested positive for influenza, and the monthly co-infection rate ranged from 7.1% to 48%. Compared to the Delta variant, individuals infected with Omicron were less likely to be co-infected and hospitalized, and individuals who received influenza vaccines were less likely to become co-infected. Three individuals had two samples collected on different dates, and all three developed a co-infection after their initial SARS-CoV-2 infection. This study demonstrates high prevalence of co-infections in central Missouri during the 2021–2022 influenza season, differences in co-infection prevalence between the Delta and the Omicron waves, and the importance of influenza vaccinations against co-infections.

Influenza and COVID-19 Co-infection

Influenza and COVID-19 Co-infection

Influenza and COVID-19 co-infection; a cross-sectional study from northern Iran

Influenza and COVID-19 co-infection; a cross-sectional study from northern Iran