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Influenza Virus B/Austria/1359417/2021-Like Strain (B/Austria/1359417/2021, Bvr-26)

This article summarizes several clinical trials investigating influenza vaccines containing the Influenza Virus B/Austria/1359417/2021-Like Strain (B/Austria/1359417/2021, BVR-26). These trials aim to evaluate the safety, immunogenicity, and efficacy of various influenza vaccine formulations in different populations, including healthy adults, older adults, and individuals with certain medical conditions. The studies explore factors such as vaccine dosage, adjuvants, and timing of administration to optimize protection against seasonal influenza.

Table of Contents

Introduction

Influenza, commonly known as the flu, is a serious respiratory illness that affects millions of people worldwide each year. To combat this virus, researchers and pharmaceutical companies continually develop and update vaccines. One such component used in recent flu vaccines is the INFLUENZA VIRUS B/AUSTRIA/1359417/2021-LIKE STRAIN (B/AUSTRIA/1359417/2021, BVR-26). This article aims to provide patients with a comprehensive understanding of this vaccine strain, its purpose, and its role in protecting against influenza.

What is INFLUENZA VIRUS B/AUSTRIA/1359417/2021-LIKE STRAIN?

The INFLUENZA VIRUS B/AUSTRIA/1359417/2021-LIKE STRAIN (B/AUSTRIA/1359417/2021, BVR-26) is a specific strain of influenza virus used in the development of flu vaccines. It is also known by its shorter name, B/Austria/1359417/2021 (B/Victoria lineage)-like virus[1]. This strain represents a type B influenza virus, which is one of the main types of influenza viruses that cause seasonal flu epidemics in humans.

The name of this strain provides important information:

  • “B” indicates it’s a type B influenza virus
  • “Austria” refers to the geographical location where the virus was first isolated
  • “1359417” is the identification number of the specific isolate
  • “2021” is the year the strain was identified
  • “BVR-26” is likely a laboratory designation for this particular variant

Purpose and Use

The primary purpose of including the B/Austria/1359417/2021-like strain in flu vaccines is to provide protection against circulating B/Victoria lineage influenza viruses. Influenza vaccines typically contain multiple strains to offer broad protection against different flu viruses expected to be prevalent in a given flu season.

This strain is used in various types of influenza vaccines, including:

  • Quadrivalent vaccines: These contain four different flu strains, typically two influenza A strains and two influenza B strains[2]
  • Inactivated vaccines: Where the virus has been killed and cannot cause infection[3]
  • Adjuvanted vaccines: Which include substances to enhance the body’s immune response[1]

Clinical Trials and Research

Several clinical trials have been conducted or are ongoing to evaluate vaccines containing the B/Austria/1359417/2021-like strain. These studies aim to assess the safety, effectiveness, and immune response generated by the vaccines. Some notable trials include:

  • A Phase 1/2 study evaluating the safety and immunogenicity of mRNA-based multivalent seasonal influenza vaccine candidates in healthy adults[2]
  • A Phase 3 trial comparing an MF59-adjuvanted quadrivalent influenza vaccine to non-adjuvanted vaccines in adults 50 years and older[1]
  • A study investigating the coadministration of influenza vaccines with COVID-19 vaccines in adults over 65 years of age[4]
  • Research on optimizing the time of day for influenza vaccine administration in adults aged 60-85 years[3]

Administration and Dosage

Vaccines containing the B/Austria/1359417/2021-like strain are typically administered as an intramuscular injection. The standard dose for most adult formulations is 0.5 ml[3]. However, specific dosages may vary depending on the particular vaccine product and the age of the recipient.

Some key points about administration:

  • Usually given as a single dose annually before the flu season
  • Can be administered to adults of various age groups, including those 65 years and older
  • May be given at the same time as other vaccines, including COVID-19 vaccines (as studied in some trials)

Safety and Side Effects

Vaccines containing the B/Austria/1359417/2021-like strain generally have a good safety profile, similar to other influenza vaccines. However, like all medical interventions, they can cause side effects. Common reactions may include:

  • Pain, redness, or swelling at the injection site
  • Fatigue
  • Headache
  • Muscle aches
  • Low-grade fever

These side effects are usually mild and resolve within a few days. Serious allergic reactions are rare but can occur. It’s important to discuss any concerns or medical history with your healthcare provider before receiving the vaccine[2].

Effectiveness and Immune Response

The effectiveness of vaccines containing the B/Austria/1359417/2021-like strain is measured through various immunological parameters in clinical trials. These include:

  • Hemagglutination inhibition (HI) antibody titers: This measures the level of antibodies produced against the virus[1]
  • Seroconversion rates (SCR): The percentage of individuals who develop a significant increase in antibody levels after vaccination[1]
  • Geometric mean titers (GMT): An average measure of antibody levels in a group of vaccinated individuals[1]

Clinical trials aim to demonstrate that vaccines containing this strain can produce a robust immune response, potentially providing protection against influenza B viruses of the Victoria lineage.

Special Populations

Research on vaccines containing the B/Austria/1359417/2021-like strain includes studies in various populations:

  • Older adults: Several trials focus on adults aged 50, 60, or 65 years and older, as this group is at higher risk for flu complications[1]
  • Individuals with chronic conditions: Some studies include participants with stable chronic diseases, recognizing the importance of protection for these at-risk groups[4]
  • Immunocompromised individuals: While generally excluded from initial trials, some studies may evaluate the vaccine’s safety and effectiveness in this population in later phases

Conclusion

The INFLUENZA VIRUS B/AUSTRIA/1359417/2021-LIKE STRAIN (B/AUSTRIA/1359417/2021, BVR-26) is an important component of current influenza vaccines, designed to protect against B/Victoria lineage flu viruses. Ongoing research and clinical trials continue to evaluate its safety, effectiveness, and potential benefits when combined with other vaccine strains or administered to different populations. As with all medical decisions, it’s important to consult with your healthcare provider to determine if a flu vaccine containing this strain is appropriate for you based on your individual health status and risk factors.

Aspect Details
Vaccine Formulations Various, including adjuvanted and non-adjuvanted, cell-derived and egg-derived, standard-dose and high-dose
Study Populations Adults 18-85 years old, with focus on older adults (50+, 65+) and some specific populations (e.g., hematological cancer patients)
Primary Outcomes Safety, reactogenicity, immunogenicity (antibody responses), and in some cases efficacy against influenza illness
Secondary Outcomes T cell responses, comparison between vaccine types, optimal administration timing, chronotype effects
Safety Assessments Solicited and unsolicited adverse events, serious adverse events, adverse events of special interest
Immunogenicity Measures Hemagglutination inhibition (HI) assay, seroconversion rates, geometric mean titers (GMT)
Special Considerations Co-administration with COVID-19 vaccines, time-of-day effects on vaccination, lot consistency

FAQ

  • What is the Influenza Virus B/Austria/1359417/2021-Like Strain? The Influenza Virus B/Austria/1359417/2021-Like Strain (B/Austria/1359417/2021, BVR-26) is a specific strain of influenza B virus used in seasonal flu vaccines. It represents one of the circulating B virus lineages and is included to provide protection against that particular strain of influenza.
  • What populations are being studied in these clinical trials? The clinical trials are studying various populations, including healthy adults, adults aged 50 years and older, adults aged 65 years and older, and individuals with certain medical conditions such as hematological cancers. Some trials also include younger adults for comparison.
  • What are the main objectives of these clinical trials? The main objectives of these trials include evaluating the safety and tolerability of the vaccines, assessing their immunogenicity (ability to provoke an immune response), comparing different vaccine formulations or dosages, and in some cases, determining vaccine efficacy in preventing influenza illness.
  • Are there any special considerations for vaccine administration being studied? Yes, some trials are investigating specific factors related to vaccine administration. For example, one study is examining the optimal time of day for administering the influenza vaccine to induce the strongest immune response in older adults. Another trial is looking at co-administration of an influenza vaccine with a COVID-19 vaccine.
  • How is the effectiveness of the vaccines being measured? The effectiveness of the vaccines is primarily measured through immunogenicity assessments, such as measuring antibody levels in the blood using tests like hemagglutination inhibition (HI) assays. Some trials also look at T cell responses and rates of influenza infection or influenza-like illness symptoms during follow-up periods.

Ongoing Clinical Trials on Influenza Virus B/Austria/1359417/2021-Like Strain (B/Austria/1359417/2021, Bvr-26)

  • Study on Immune Responses to Avian Influenza Vaccine with A/Turkey/Turkey/1/05 (H5N1)-Like Strain in Patients with Avian and Seasonal Influenza

    Recruiting

    3 1 1 1
    Investigated diseases:
    Investigated drugs:
    Finland

  • Study Comparing High-Dose and Standard-Dose Inactivated Influenza Vaccines in Adults with Blood Cancer

    Recruiting

    3 1 1 1
    Investigated diseases:
    Investigated drugs:
    Belgium

  • Study of Flu Vaccine and Pembrolizumab for Patients with Early Colorectal Cancer

    Recruiting

    2 1 1 1
    Investigated drugs:
    Denmark

  • Study of Influenza Vaccine Effects on Immune Response in the Nose and Airways in Adults Seeking Protection Against Seasonal Flu

    Not recruiting

    3 1 1 1
    Investigated drugs:
    France

  • Study of mRNA-based seasonal influenza vaccine to evaluate immune response and safety in adults 18 years and older

    Not recruiting

    2 1 1 1
    Investigated diseases:
    Investigated drugs:
    Belgium

  • Study of mRNA-based seasonal influenza vaccine combinations compared to standard influenza vaccines in adults aged 18 and older

    Not recruiting

    2 1 1 1
    Investigated diseases:
    Investigated drugs:
    Belgium

  • Study on the Safety and Immune Response of a High-Dose Influenza Vaccine in Adults Aged 60 and Over, Comparing Trivalent Influenza Vaccine with a Drug Combination

    Not recruiting

    3 1 1 1
    Investigated drugs:
    Belgium Bulgaria Estonia Finland Spain

  • Study on the Safety and Immune Response of aQIVc HD Vaccine Compared to a Drug Combination for Adults 50 Years and Older at Risk of Flu Complications

    Not recruiting

    3 1 1 1
    Investigated diseases:
    Investigated drugs:
    Denmark Estonia Germany

  • Study on the Best Time for Influenza Vaccine Administration in Adults Aged 60-85 Using Influenza Vaccine and Drug Combination

    Not recruiting

    3 1 1 1
    Investigated diseases:
    Investigated drugs:
    The Netherlands

  • Study on the Immune Response of COVID-19 Vaccine Tozinameran with Flu Vaccine Combinations in Adults Aged 65 and Over

    Not recruiting

    2 1 1
    Investigated diseases:
    Investigated drugs:
    Belgium The Netherlands

Glossary

  • Adjuvant: A substance added to a vaccine to enhance the body's immune response to the vaccine, potentially allowing for a lower dose of the vaccine antigen or improving its efficacy in certain populations.
  • Antibody titer: A measurement of the amount or concentration of antibodies in the blood, used to determine the strength of the immune response to a vaccine or infection.
  • Geometric Mean Titer (GMT): A type of average used to measure antibody levels in a group of study participants, calculated by multiplying all the values and then taking the nth root of the product, where n is the number of values.
  • Hemagglutination inhibition (HI) assay: A laboratory test used to measure antibodies that can prevent influenza viruses from binding to red blood cells, which is an indicator of potential protection against infection.
  • Immunogenicity: The ability of a substance, such as a vaccine, to provoke an immune response in the body.
  • Quadrivalent influenza vaccine: A flu vaccine that protects against four different influenza viruses: two influenza A viruses and two influenza B viruses.
  • Seroconversion: The development of detectable antibodies in the blood directed against an infectious agent, such as a virus, following vaccination or infection.
  • Seroprotection: The presence of sufficient antibodies in the blood to protect against a specific infection, often defined as an antibody titer above a certain threshold.

References

  1. http://clinicaltrials.eu/trial-id/2023-503763-42-00
  2. http://clinicaltrials.eu/trial-id/2022-502308-66-00
  3. http://clinicaltrials.eu/trial-id/2024-513558-30-00
  4. http://clinicaltrials.eu/trial-id/2023-506189-29-00