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Pneumococcal Polysaccharide Serotype 33F Conjugated To Crm197

This article summarizes clinical trials investigating the use of pneumococcal polysaccharide serotype 33F 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 33F Conjugated to CRM197?

Pneumococcal Polysaccharide Serotype 33F Conjugated to CRM197 is a component of pneumococcal vaccines designed to protect against infections caused by the Streptococcus pneumoniae bacteria, specifically the 33F serotype[1]. This component is part of newer, more comprehensive pneumococcal vaccines that aim to provide broader protection against various strains of pneumococcal bacteria.

The vaccine component consists of two main parts:

  • Pneumococcal Polysaccharide Serotype 33F: This is a sugar molecule (polysaccharide) found on the surface of the 33F strain of pneumococcal bacteria.
  • CRM197: This is a carrier protein that helps enhance the immune response to the polysaccharide.

How Does it Work?

The vaccine works by stimulating the body’s immune system to produce antibodies against the 33F serotype of pneumococcal bacteria. When the polysaccharide from the bacteria is conjugated (attached) to the CRM197 protein, it creates a stronger and more lasting immune response[1].

This process, known as conjugation, helps the body’s immune system recognize and remember the bacterial polysaccharide more effectively. If a person vaccinated with this component later encounters the 33F serotype of pneumococcal bacteria, their immune system can quickly recognize and fight off the infection.

Clinical Trials and Research

Several clinical trials have been conducted or are ongoing to evaluate the safety and effectiveness of vaccines containing this component. Some key studies include:

  • A Phase 3 study evaluating a 20-valent pneumococcal conjugate vaccine (which includes the 33F serotype) in adults aged 18 to 64 at increased risk for pneumococcal disease[2].
  • A study comparing the immune response of a new 21-valent pneumococcal conjugate vaccine (including 33F) to existing vaccines in adults 50 years and older[3].
  • Research on the effectiveness of a 20-valent pneumococcal conjugate vaccine against community-acquired pneumonia in adults 65 years and older[4].

Who Can Receive This Vaccine?

Vaccines containing this component are typically recommended for:

  • Adults aged 65 years and older
  • Adults aged 18-64 with certain risk factors or medical conditions that increase their risk of pneumococcal disease
  • Children and adolescents with specific health conditions that put them at higher risk for pneumococcal infections[5]

How is it Administered?

The vaccine is typically given as an intramuscular injection, usually in the upper arm (deltoid muscle). For most adults, a single dose is recommended. However, some individuals may require additional doses based on their age, health status, and previous vaccination history[6].

Safety and Side Effects

Clinical trials have shown that vaccines containing this component are generally safe and well-tolerated. Common side effects may include:

  • Pain, redness, or swelling at the injection site
  • Fatigue
  • Headache
  • Muscle pain
  • Joint pain

These side effects are usually mild and resolve within a few days. Serious allergic reactions are rare but can occur[7].

Effectiveness

Studies have shown that vaccines containing this component can effectively stimulate the immune system to produce antibodies against the 33F serotype of pneumococcal bacteria. The effectiveness is often measured by looking at the levels of antibodies in the blood (known as immunogenicity) and the ability of these antibodies to kill the bacteria (known as opsonophagocytic activity)[3].

Research is ongoing to determine the real-world effectiveness of these vaccines in preventing pneumococcal disease caused by the 33F serotype.

Conclusion

Pneumococcal Polysaccharide Serotype 33F Conjugated to CRM197 is an important component of newer pneumococcal vaccines. It helps protect against a specific strain of pneumococcal bacteria that can cause serious infections. As part of broader pneumococcal vaccines, it contributes to providing more comprehensive protection against pneumococcal disease, especially for those at higher risk of infection.

Trial ID Study Focus Population Key Outcomes
2022-501519-15-00 Immune response in lymph nodes after pneumococcal vaccination Healthy adults 20-40 years old Germinal center B cell frequency, T follicular helper cell frequency
2022-501988-40-00 Co-administration of 20-valent pneumococcal and RSV vaccines Adults ≥60 years old Non-inferiority of immune responses, safety
2022-502791-22-01 Safety and immunogenicity of V116 vaccine Adults 18-64 years at increased risk Adverse events, OPA antibody titers
2022-503144-40-00 Safety and immunogenicity of V116 vaccine Adults ≥50 years old Adverse events, OPA antibody titers vs PPSV23
2023-506236-32-00 Safety and immunogenicity of V116 vaccine Children/adolescents at increased risk Adverse events, OPA antibody titers vs PPSV23
2023-507293-40-00 Effectiveness of 20-valent pneumococcal vaccine Adults ≥65 years old Vaccine effectiveness against pneumonia

FAQ

  • What is pneumococcal polysaccharide serotype 33F conjugated to CRM197? It is a component of some pneumococcal conjugate vaccines that helps protect against infections caused by the 33F serotype of Streptococcus pneumoniae bacteria. The bacterial polysaccharide is linked to a carrier protein (CRM197) to enhance the immune response.
  • What populations are being studied in these clinical trials? The trials are studying various adult populations, including healthy adults over 50 or 60 years old, adults 18-64 years at increased risk of pneumococcal disease, and children/adolescents with risk factors for pneumococcal infections.
  • What are the main outcomes being measured? Key outcomes include safety (adverse events), immunogenicity (antibody levels and functional antibody activity), and vaccine effectiveness against pneumococcal pneumonia in some studies.
  • How is the immune response to the vaccine measured? The immune response is primarily measured through blood tests looking at antibody levels (IgG concentrations) and functional antibody activity (opsonophagocytic activity) against the vaccine serotypes.
  • Are these vaccines already approved or still experimental? Some of the vaccines, like the 20-valent Apexxnar, are already approved. Others, like the 21-valent V116 vaccine, are still experimental and being evaluated in clinical trials.

Ongoing Clinical Trials on Pneumococcal Polysaccharide Serotype 33F 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

  • Serotype: A distinct variation within a species of bacteria or virus, identified by specific antigens on its surface. For pneumococcal bacteria, serotypes are distinguished by differences in their polysaccharide capsule.
  • CRM197: A non-toxic mutant of diphtheria toxin used as a carrier protein in conjugate vaccines to enhance the immune response, especially in young children.
  • Opsonophagocytic activity (OPA): A measure of antibody function that assesses the ability of antibodies to facilitate the uptake and killing of bacteria by immune cells.
  • Immunogenicity: The ability of a substance, such as a vaccine, to provoke an immune response in the body.
  • 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.
  • 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.
  • Pneumococcal disease: Infections caused by Streptococcus pneumoniae bacteria, which can range from ear and sinus infections to pneumonia and invasive diseases like meningitis.
  • Invasive pneumococcal disease (IPD): A severe infection where pneumococcal bacteria enter normally sterile sites like blood or cerebrospinal fluid.
  • Community-acquired pneumonia (CAP): Pneumonia acquired outside of a healthcare setting, often caused by pneumococcal bacteria among other pathogens.
  • Vaccine effectiveness (VE): A measure of how well a vaccine prevents disease in real-world conditions, usually expressed as a percentage.

References

  1. http://clinicaltrials.eu/trial-id/2022-501519-15-00
  2. http://clinicaltrials.eu/trial/study-on-the-v116-vaccine-for-adults-aged-18-64-at-increased-risk-of-pneumococcal-infection/
  3. http://clinicaltrials.eu/trial-id/2022-503144-40-00
  4. http://clinicaltrials.eu/trial/study-on-the-effectiveness-of-20-valent-pneumococcal-conjugate-vaccine-for-preventing-pneumonia-in-adults-aged-65-and-older/
  5. http://clinicaltrials.eu/trial/study-on-the-safety-and-immune-response-of-v116-vaccine-in-children-and-adolescents-at-higher-risk-for-pneumococcal-disease/
  6. http://clinicaltrials.eu/trial-id/2022-501988-40-00
  7. http://clinicaltrials.eu/trial-id/2022-502791-22-01