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History Avian influenza A/H5N8 virus infections have been widespread in wild and domestic bird populations, with transmission restricted to a handful of human poultry workers. The safety and immunogenicity of a monovalent inactivated influenza A/H5N8 virus vaccine administered with and without AS03 or MF59 adjuvants was determined by a phase 1, randomized, blinded trial. For the homologous influenza A/H5N8 and three heterologous influenza A/H5 viruses, the human immunologicity was assessed during 21 days after the second dose of vaccine using hemagglutination inhibition and microneutralization assays. When compared to the MF59-adjudvanted groups, seroprotection was more prevalent in groups that had received AS03 Plus 7. 5 or 15 g of vaccine, relative to the MF59-adjuvanted groups, while unadjuvanted vaccines had a poor response. For all three heterologous strains of influenza A/H5 virus, HAI and MN GMTs and seroconversion rates were poor across all study groups.
Source link: https://europepmc.org/article/MED/36610741
Influenza A/H5N8 viruses infect poultry and wild birds in several countries. Methods We conducted a phase I, cohort-randomized, double-blind, placebo-controlled trial of inactivated influenza A/H5N8 vaccines administered with or without adjuvant adjuvant. Two doses of AS03-adjuvanted vaccine containing 3. 75 bcg or 15 % hemagglutininin; two doses of 15 bcg hemagglutinin; or one dose of non-adjuvanted vaccine; or one dose of non-adjuvanted vaccine containing 3. 75 bcg or 15 bcg hemagglutinin; or one dose of non-adjuvanted vaccine; Two doses of MF59-adjuvanted vaccine containing 3. 75 %u03bcg or 15 bcg HA, or 15 u03bcg HA of non-adjuvanted vaccines were given to Cohort 2 patients. Antibody counts returned to normal 12 months after the second vaccination in all groups except the 15 bcg AS03-adjuvanted group. In a subgroup of both 15 u03bcg adjuvanted groups, cross-reactive antibodies to clade 2. 3. 4. 4b strains isolated from human infections were demonstrated. Two doses of influenza A/H5N8 vaccine were well tolerated.
Source link: https://europepmc.org/article/MED/36610728
Live attenuated influenza vaccines can be administered intranasally, stimulate a broad and robust immune response, yields during manufacturing are higher than that of inactivated influenza vaccines, and are therefore a viable option for young children in poor countries. Until recently, two random controlled trials assessing Russian-backbone trivalent LAIV in children reported contradictory findings; vaccine effectiveness differed between Bangladesh and Senegal against all influenza viral strains. The CDC Advisory Committee on Immunization Practices recommended against the use of LAIV during the 2016-17 and 2017-18 influenza seasons, owing to the Ann Arbor-based LAIV's ineffectiveness against influenza Apdm09-like viruses. LAIV had significantly lower efficacy in comparison to IIV in 2021, according to the findings from a two-year RCT evaluating the Russian-backbone trivalent LAIV in rural north India, but in Year 2, the vaccine efficacy for LAIV and IIV were comparable.
Source link: https://europepmc.org/article/MED/36604216
For the large number of patients with chronic hepatitis B virus infection, studies on their immune responses to these vaccines are still lacking. Eight CHB patients were then injected with SARSu20102 vaccine during a 1200-year follow-up, and serum antibodies against SARSu20102 were further determined. On the 28th day of influenza vaccination, three influenza antibodies levels in CHB patients appeared to be lower than in HCs. Antiu2010SARSu2010CoVu20102 antibodies in patients with influenza vaccination history were higher in patients with influenza vaccination history than in patients without history. A history of inactivated influenza vaccination within a year before the introduction of activated SARS-20202 vaccination may have a greater antiu2010SARS+u20102 antibodies, as shown by the U2010CoVu20102 antibody response in a week. Patients with CHB with an activated influenza vaccine seem to have been reduced, particularly in those with cirrhosis. A history of inactivated influenza vaccination within one year before the inactivated SARSu20102 vaccination, which may result in a stronger anti-u2010SARSu20102 antibody response in a stoutified SARS20102 vaccination.
Source link: https://europepmc.org/article/MED/PMC9803931
However, Coronavirus 2019 vaccinees have often been infected with COVID-19 variants, and they may continue to suffer from long-term immunity and less-effective protection provided by available vaccines. In addition, the latest COVID-19 vaccines do not prevent viral transmission and ward off only around 15% of breakthrough infections. To guide influenza vaccination manufacturing by pharmaceutical firms, the World Health Organization recommends in advance which influenza strains are expected to be prevalent during influenza season.
Source link: https://europepmc.org/article/MED/36594004
Pre-vaccination HAI antibody titers are traditionally measured using latest season vaccine strain antigens rather than the previous season vaccinations that have been immunized, and they do not accurately represent circulating antibody titers from prior season vaccination. Participants in a longitudinal influenza immunization survey from 2014 to 2017, during which influenza A virus H3N2 and influenza B virus strains were modified in 2015 and 2016 respectively, including previously published pre-vaccination HAI antibody titers developed using prior season vaccine strain antigens. Conclusions: : The conventional model overestimates interseason HAI antibody decline by underestimating residual antibody titers from prior season vaccination, particularly when virus strains in the vaccine formula change.
Source link: https://europepmc.org/article/PPR/PPR589464
To prevent a wide variety of influenza viruses, a universal influenza vaccine is urgently needed. We summarize candidate influenza vaccines that meet two main criteria: first, they are intended to provide protection against multiple influenza viruses; second, they have passed regulatory inspections and are currently in various stages of clinical trials; and, third, they are intended to provide relief against two influenza viruses. In the development of universal influenza vaccines, we discuss these vaccine candidates based on the various vaccine-production platforms, with a focus on antigen selection, manufacture, adjuvants, immunomodulators, and vaccine delivery methods.
Source link: https://europepmc.org/article/MED/36574905
Background: Although obtaining appropriate variables to account for potential bias is important, developing the most useful variables should be prioritized. Establishing a large research network to conduct influenza vaccine effectiveness studies while collecting valid variables to account for potential bias is critical; the most significant variables should be prioritized. In the DRIVE multi-country network of sites doing test-negative design studies, we investigated the effects of potential confounders on IVE. Methods We created a targeted acyclic graph to show the relationship between influenza vaccination, medically attended influenza disease, confounders, and other variables. Only adjustment for lung disease in older adults in the primary care setting resulted in a marginal change of the IVE point figure by more than ten percent. Practical implications are that necessitating fewer variables lowers the entry criteria for enrollment of sites in IVE studies and simplifies the gathering of data from various IVE studies or research networks.
Source link: https://europepmc.org/article/MED/36550627
Background Immune responses to influenza vaccination tend to be lower among older, commonly vaccinated adults. Methods A prospective, observational study of the immunogenicity of the 2018-2019 influenza vaccine found community-dwelling older adults u2265 56 years of age – was published. Hemagglutination inhibition antibody titers were measured pre-vaccination and four weeks after vaccination to determine geometric mean titers, seropositivity, seroconversion, and geometric mean fold rises. For each vaccine antigen, Linear regression models investigated the relationship between predictors of GMFR for each vaccine antigen. Among the 91 people who received egg-free influenza vaccines, 84 received quadrivalent recombinant influenza vaccine, and 7 received quadrivalent cell culture-based influenza vaccine. Seroconversion by antigen ranging from 16. 5 percent for A and B/Colorado to 37. 4 percent for A; 40 participants failed to seroconvert to no antigen, with no one identifying the A. Conclusion Overall, the pre-vaccination seropositivity was high, with just over half of the cohort seroconverted to a u22651 vaccine antigen.
Source link: https://europepmc.org/article/MED/36543682
Influenza vaccines were the most commonly used vaccine during pregnancy globally before COVID-19. Despite this, influenza vaccine hesitancy is widespread, with few countries reporting immunization rates in pregnant women over 50%. Though some research has shown promising results, no single intervention has consistently raised influenza vaccination uptake during pregnancy. Future plans addressing several levels of vaccine hesitancy will be needed to obtain the potential health benefits of prenatal immunization services using a social-ecological framework.
Source link: https://europepmc.org/article/MED/36535646
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