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Pneumococcal Polysaccharide Serotype 22F Conjugated To Crm197

This article summarizes several clinical trials investigating the use of pneumococcal polysaccharide serotype 22F conjugated to CRM197 as part of pneumococcal conjugate vaccines. These trials aim to evaluate the safety, immune response, and effectiveness of new pneumococcal vaccines containing this serotype, particularly in adults and high-risk populations. The studies examine factors like antibody levels, opsonophagocytic activity, and protection against pneumococcal disease.

Table of Contents

What is Pneumococcal Polysaccharide Serotype 22F Conjugated to CRM197?

Pneumococcal Polysaccharide Serotype 22F Conjugated to CRM197 is a component of a vaccine designed to prevent pneumococcal disease. It is part of a larger group of vaccines known as pneumococcal conjugate vaccines. These vaccines help protect against infections caused by the bacterium Streptococcus pneumoniae, also known as pneumococcus.[1]

How Does it Work?

This vaccine component works by stimulating the body’s immune system to produce antibodies against a specific type (serotype) of pneumococcus, namely serotype 22F. The “conjugated” part means that the pneumococcal polysaccharide (a sugar molecule from the bacterial surface) is chemically linked to a carrier protein called CRM197. This conjugation helps to enhance the immune response, especially in young children.[1]

Vaccine Composition

The Pneumococcal Polysaccharide Serotype 22F Conjugated to CRM197 is just one of many components in pneumococcal conjugate vaccines. For example, it is included in a 20-valent pneumococcal conjugate vaccine (20vPnC) along with 19 other serotypes. This vaccine is known by the brand name Apexxnar and is produced by Pfizer.[2]

Clinical Trials and Research

Several clinical trials have been conducted or are ongoing to evaluate the safety, tolerability, and effectiveness of vaccines containing this component:

  • A Phase 3 study is evaluating the immune response, safety, and reactogenicity of a 20-valent pneumococcal conjugate vaccine (which includes serotype 22F) when co-administered with an RSV vaccine in adults aged 60 years and older.[1]
  • Another Phase 3 study is assessing the safety, tolerability, and immunogenicity of a 21-valent pneumococcal conjugate vaccine (V116) in pneumococcal vaccine-naïve adults 50 years of age or older.[3]
  • A Phase 4 study is investigating the effectiveness of a 20-valent pneumococcal conjugate vaccine against vaccine-type radiologically-confirmed community-acquired pneumonia in adults ≥65 years of age.[2]

Who is the Target Population?

The target population for vaccines containing this component varies depending on the specific vaccine formulation and approved indications. Generally, these vaccines are intended for:

  • Adults aged 65 years and older
  • Adults aged 18-64 with certain risk factors or medical conditions
  • Children and adolescents with increased risk of pneumococcal disease

For example, one clinical trial is specifically studying the vaccine in adults aged 18 to 64 years with increased risk for pneumococcal disease, including those with conditions such as diabetes mellitus, chronic liver disease, chronic lung disease, chronic heart disease, or chronic kidney disease.[4]

How is it Administered?

Vaccines containing Pneumococcal Polysaccharide Serotype 22F Conjugated to CRM197 are typically administered as an intramuscular injection. The usual dose is 0.5 ml. Depending on the specific vaccine and vaccination schedule, it may be given as a single dose or as part of a series.[1]

Effectiveness

The effectiveness of vaccines containing this component is being evaluated in ongoing clinical trials. Researchers are measuring various indicators of immune response, such as:

  • Opsonophagocytic activity (OPA) antibody titers, which indicate the ability of antibodies to help destroy the bacteria
  • Immunoglobulin G (IgG) concentrations, which measure the level of specific antibodies in the blood
  • The proportion of participants achieving a significant increase in antibody levels after vaccination

These measures help determine how well the vaccine stimulates the immune system to protect against pneumococcal disease.[3]

Safety and Side Effects

The safety profile of vaccines containing this component is being closely monitored in clinical trials. Common side effects may include:

  • Injection site reactions (pain, redness, swelling)
  • Systemic reactions (fatigue, headache, muscle pain, joint pain)
  • Fever

Serious adverse events are rare but are being carefully tracked in the studies. It’s important to note that the benefits of vaccination generally outweigh the risks for individuals in the recommended target groups.[4]

Conclusion

Pneumococcal Polysaccharide Serotype 22F Conjugated to CRM197 is an important component of newer pneumococcal conjugate vaccines. These vaccines aim to provide broader protection against pneumococcal disease, particularly in vulnerable populations. Ongoing research continues to evaluate their safety, effectiveness, and potential impact on public health. As with any medical intervention, individuals should consult with their healthcare provider to determine if vaccination is appropriate for their specific situation.

Trial Focus Key Endpoints Population Vaccine
Immune response in lymph nodes Germinal center B cell frequency, T follicular helper cell frequency Healthy adults 20-40 years old 20-valent pneumococcal conjugate vaccine (Apexxnar)
Co-administration with RSV vaccine Opsonophagocytic antibody titers, adverse events Adults ≥60 years old 20-valent pneumococcal conjugate vaccine (Apexxnar)
Safety and immunogenicity in at-risk adults Adverse events, opsonophagocytic activity, IgG levels Adults 18-64 years with risk conditions 21-valent pneumococcal conjugate vaccine (V116)
Comparison to PPSV23 in older adults Opsonophagocytic activity, IgG levels, adverse events Adults ≥50 years old 21-valent pneumococcal conjugate vaccine (V116)
Safety and immunogenicity in at-risk youth Adverse events, opsonophagocytic activity, IgG levels Children/adolescents with risk conditions 21-valent pneumococcal conjugate vaccine (V116)
Effectiveness against pneumonia Vaccine effectiveness against radiologically-confirmed CAP Adults ≥65 years old 20-valent pneumococcal conjugate vaccine (Apexxnar)

FAQ

  • What is the main purpose of these clinical trials? The main purpose is to evaluate the safety, immune response, and effectiveness of new pneumococcal conjugate vaccines containing serotype 22F, particularly in adults and high-risk populations.
  • What age groups are being studied in these trials? The trials are studying various adult age groups, including adults 50 years and older, 60 years and older, and 18-64 year olds at increased risk for pneumococcal disease. One trial is also looking at children and adolescents at higher risk.
  • What are some of the key outcomes being measured? Key outcomes include antibody levels, opsonophagocytic activity (ability of antibodies to kill bacteria), rates of adverse events, and protection against pneumococcal pneumonia and invasive disease.
  • How do these new vaccines differ from older pneumococcal vaccines? These new vaccines contain additional pneumococcal serotypes, including 22F, that were not in older vaccines. They aim to provide broader protection against more strains of pneumococcal bacteria.
  • Are there any special populations being studied? Yes, some trials are focusing on adults with increased risk factors for pneumococcal disease, such as chronic medical conditions. One trial is specifically studying children and adolescents at higher risk.

Ongoing Clinical Trials on Pneumococcal Polysaccharide Serotype 22F Conjugated To Crm197

  • Study of Pneumococcal Vaccine Response in Patients Without a Spleen: Comparing Vaccination Before and After Spleen Removal Using PCV20 and PCV21

    Recruiting

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

  • Study on the Safety and Immune Response of V116 Vaccine for Pneumococcal Disease in Adults Aged 50 and Older

    Not recruiting

    1 1 1 1
    Investigated drugs:
    Germany Spain

  • Study on the Safety and Immune Response of a 21-Valent Pneumococcal Conjugate Vaccine in Healthy Infants and Toddlers

    Not recruiting

    1 1 1 1
    Investigated drugs:
    Belgium Czechia Estonia Finland Germany Greece +3

  • Study on the Safety and Immune Response of V116 Vaccine in Children and Adolescents at Higher Risk for Pneumococcal Disease

    Not recruiting

    1 1 1 1
    Investigated diseases:
    Investigated drugs:
    Finland France Poland Spain Sweden

  • Study on the V116 Vaccine for Adults Aged 18-64 at Increased Risk of Pneumococcal Infection

    Not recruiting

    1 1 1
    Investigated drugs:
    Poland

Glossary

  • Pneumococcal polysaccharide: The sugar coating on the outside of pneumococcal bacteria that helps the immune system recognize and fight the bacteria.
  • Serotype: A distinct variation within a species of bacteria or virus. For pneumococcus, serotypes are distinguished by differences in their polysaccharide coating.
  • CRM197: A non-toxic mutant of diphtheria toxin used as a protein carrier in conjugate vaccines to enhance the immune response, especially in young children.
  • Conjugate vaccine: A type of vaccine that joins a weak antigen (like a bacterial polysaccharide) to a stronger antigen to create a more powerful immune response.
  • Opsonophagocytic activity (OPA): A measure of antibody function, specifically the ability of antibodies to help immune cells engulf and destroy bacteria.
  • Immunoglobulin G (IgG): The most common type of antibody in blood and other body fluids, playing a crucial role in fighting bacterial and viral infections.
  • Geometric mean titer (GMT): A way of averaging antibody levels across a group of people that reduces the impact of very high or low individual values.
  • Adverse event (AE): Any unfavorable and unintended sign, symptom, or disease temporarily associated with the use of a medical treatment or procedure.
  • Invasive pneumococcal disease (IPD): A severe infection caused by pneumococcal bacteria entering normally sterile sites like blood or spinal fluid.
  • Community-acquired pneumonia (CAP): Pneumonia acquired outside of a healthcare setting, often caused by pneumococcal bacteria among other pathogens.

References

  1. http://clinicaltrials.eu/trial-id/2022-501988-40-00
  2. http://clinicaltrials.eu/trial/study-on-the-effectiveness-of-20-valent-pneumococcal-conjugate-vaccine-for-preventing-pneumonia-in-adults-aged-65-and-older/
  3. http://clinicaltrials.eu/trial-id/2022-503144-40-00
  4. http://clinicaltrials.eu/trial/study-on-the-v116-vaccine-for-adults-aged-18-64-at-increased-risk-of-pneumococcal-infection/