View clinical trials related to Influenza, Human.
Filter by:This study examines how the immune system responds to the flu virus (H3N2) during and after infection and how the flu virus is transmitted in the environment. The study will used a flu virus called the H3N2 influenza challenge virus which was produced specifically for use in clinical research in controlled conditions. The study will also assess the safety of the H3N2 influenza challenge in healthy subjects. Mild to moderate symptoms are expected based on previous studies with this strain of influenza.
The main objective of this study was to evaluate the immunogenicity and safety of the booster dose of COVID-19 inactivated vaccine and co-immunization with quadrivalent influenza vaccine and 23-valent pneumonia polysaccharide vaccine in people aged 18 years and older. A randomized controlled, open trial design was adopted. The study was conducted with informed consent of the subjects for immunogenicity and safety in the population aged 18 years and older. A total of 3000 healthy subjects were selected, (1)600 healthy subjects were selected for the immunogenicity and safety study of co-immunization, 300 in the adult group (18-59 years old) and 300 in the elderly group (60 years old and above); (2) 2400 healthy subjects were selected for the observational study of the safety of co-immunization, 1200 in the adult group (18-59 years old) and 1200 in the elderly group (60 years old and above ) 1200 people.
Background: Respiratory viruses, like the flu or COVID-19, cause significant illness and death worldwide. Researchers want to collect samples from people with respiratory virus infections. The samples in this natural history study will be used in future research. Objective: To obtain samples from people with respiratory viruses to learn more about respiratory virus infections and the immune responses against them. Eligibility: People aged 3 and older who have or are suspected to have a respiratory virus infection. Design: Participants will be screened with a medical record review. Participants will give blood samples. Data from their medical records will be collected. Participants will give nose samples. A soft plastic strip will be put into each nostril for a minute. They may also give nose, mouth (back of the throat), or saliva samples using swabs. Participants may receive kits by mail to collect nose and blood samples at home. They will use soft plastic strips to collect nose samples. To collect blood, they will prick their finger and dab a few drops of blood on four plastic tips. If a participant is in the hospital, air samples may be collected in their room. Participation will last for up to 2 years. After 2 years, participants may be asked for their consent again to give new samples and new medical data.
Study Description: Background: Well-known fact that the number of cardiovascular diseases is on the rise during influenza epidemic. It is conceivable that influenza may precipitate plaque rupture, increase cytokines with central roles in plaque destabilization and trigger the coagulation cascade. A number of studies have shown that the risk of cardiovascular complications (ACS, stroke, CHF decompensation, cardiac arrhythmias) seem to be reduced following influenza vaccination. The Influenza Vaccination After Myocardial Infarction study data published in September 2021 have demonstrated a significant decrease of mortality (by 40%) during 1 year of follow-up in patients with myocardial infarction (MI) who has been vaccinated during the first 72 hours. Objective: the objective is to find out whether influenza vaccination protects against cardiovascular events and death in ACS & CHF patients vaccinated during hospitalization Methods: Population: 400 patients aged 65 and older with acute coronary syndrome are randomized 1:1 and followed up via telephone calls and registries (AIS "Mortality"). Patients will be included in the study in cardiology departments № 1, 2, 3, 5, 6 of the State Budgetary Healthcare Institution "Samara Regional Clinical Cardiology Dispensary named after V.P. Polyakov" Intervention: Influenza vaccination. Control: group of unvaccinated patients. Planned study period is 1 year.
Lung allograft recipients have a higher burden of influenza disease and greater associated morbidity and mortality compared with healthy controls. Induction and early maintenance immunosuppression is thought to impair immunogenicity to standard dose inactivated influenza vaccine. This early post-transplant period is when immunity is most desirable, since influenza disease during this time frame is associated with adverse consequences. Thus, strategies to reduce severe influenza disease in this highly susceptible population are critical. No trials in lung transplant recipients have evaluated two doses of HD-IIV within the same influenza season as a strategy to improve immunogenicity and durability of influenza prevention. Furthermore, no influenza vaccine trials have focused on enrollment of subjects at early post-transplant timepoints. Very few studies have been performed in solely lung allograft recipients. Immunosuppression intensity is highest in lung patients, thereby limiting comparisons to recipients of heart, liver, and kidney transplants. Therefore, studies to assess both HD-IIV and two-dose strategies in the same influenza season in post-lung transplant recipients are greatly needed. The central hypothesis of our proposal is that lung allograft recipients who are 1-35 months post-transplant and receiving two doses of HD-quadrivalent inactivated influenza vaccine (QIV) will have higher HAI geometric mean titers (GMT) to influenza antigens compared to those receiving two doses of SD-QIV. To test this hypothesis and address the above critical knowledge gaps, we propose to conduct a phase II, multi-center, randomized, double-blind, controlled immunogenicity and safety trial comparing the administration of two doses of HD-QIV to two doses of SD-QIV in lung allograft recipients 1-35 months post-transplant. The results of this clinical trial will address significant knowledge gaps regarding influenza vaccine strategies (e.g., one vs. two doses and HD-QIV vs. SD-QIV) and immune responses in lung transplant recipients and will guide vaccine recommendations during the post-transplant period.
This is a randomized, double-blind, placebo-controlled pilot study of the efficacy and safety of baloxavir in combination with oseltamivir (standard of care) for the treatment of influenza in allogeneic stem cell transplant patients. Although there are no data about this treatment option currently available, the investigator hypothesizes that combination therapy may be more effective in clearing influenza virus infection and decreasing the rate of emergence of resistant influenza in immunocompromised human hosts.
The objectives of this study are to understand the long-term consequences of repeated annual influenza vaccination among healthcare workers (HCWs) and to use statistical and mathematical modelling to elucidate the immunological processes that underlie vaccination responses and their implications for vaccination effectiveness. These objectives will be achieved by pursuing three specific aims: 1. To study the immunogenicity and effectiveness of influenza vaccination by prior vaccination experience 2. To characterize immunological profiles associated with vaccination and infection 3. To evaluate the impact of immunity on vaccination effectiveness. Under Aim 1, a cohort of hospital workers will be recruited and followed for up to 4 years to assess their pre- and post-vaccination and post-season antibody responses, and their risk of influenza infection. These outcomes will be compared by vaccination experience, classified as frequently vaccinated (received ≥3 vaccines in the past 5 years), infrequently vaccinated (<3 vaccinations in past 5 years), vaccinated once, vaccine naïve and unvaccinated. In Aim 2, intensive cellular and serological assessments will be conducted to dissect the influenza HA-reactive B cell and antibody response, and build antibody landscapes that typify the different vaccination groups. In Aim 3, the data generated in Aims 1 and 2 will be used to develop a mathematical model that considers prior infection, vaccination history, antibody kinetics, and antigenic distance to understand the effects of repeated vaccination on vaccine effectiveness. Completion of the proposed research will provide evidence to inform decisions about continued support for influenza vaccination programs among HCWs and general policies for annual influenza vaccination, as well as much needed clarity about the effects of repeated vaccination. In March-April 2020 pursuant to the SARS-CoV-2 global pandemic an administrative supplement added a SARS-CoV-2 protocol addendum for follow-up of COVID-19 infections amongst our HCW participant cohort. The following objectives were added: 1. To estimate risk factors and correlates of protection for SARS-CoV-2 infection amongst HCW 2. To characterize viral kinetics and within-host viral dynamics of SARS-CoV-2 infecting HCW 3. To characterize immunological profiles following infection by SARS-CoV-2 4. To characterize immunological profiles following vaccination for SARS-CoV-2.
Cellular and humoral immune responses before and after seasonal influenza vaccination will be assessed. Each year, up to 100 participants will be enrolled. To study age-specific differences in immune responses, participants with various years of birth will be enrolled. The investigators hypothesize that humans with different birth years will mount antibody and cellular responses of different specificities following seasonal influenza vaccination.
"Influenza and the Heart: An investigation into the acute and lasting cardiac effects of influenza infection" the investigators aim to assess the mechanisms for cardiovascular disease in patients suffering an acute influenza infection. The project will be carried out by creating a prospective clinical cohort study of consecutive patients hospitalized at Herlev & Gentofte University Hospital with a laboratory confirmed influenza.
This study was a randomized controlled trial to investigate the immune response of influenza vaccines when doses were increased. and a second vaccination together with an increase in the amount of vaccine in patients with chronic kidney disease receiving hemodialysis