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Pneumococcal Polysaccharide Serotype 19A Conjugated To Crm197

This article summarizes clinical trials investigating the use of pneumococcal polysaccharide serotype 19A conjugated to CRM197 vaccine. This vaccine is part of broader pneumococcal conjugate vaccines being studied to prevent pneumococcal disease in various populations. The trials examine the safety, immune response, and effectiveness of these vaccines in different age groups and risk populations.

Table of Contents

What is the pneumococcal polysaccharide serotype 19A conjugate vaccine?

The pneumococcal polysaccharide serotype 19A conjugate vaccine is a component of newer pneumococcal vaccines designed to protect against infections caused by the bacterium Streptococcus pneumoniae, also known as pneumococcus.[1] This specific component targets the 19A serotype of pneumococcus, which is one of the strains that can cause serious infections.

The vaccine contains a small amount of the outer sugar coating (polysaccharide) of the 19A pneumococcal bacteria. This polysaccharide is chemically attached (conjugated) to a harmless protein called CRM197. The combination helps trigger a stronger immune response than the polysaccharide alone would.[1]

How does it work?

When you receive the vaccine, your immune system recognizes the pneumococcal polysaccharides as foreign and produces antibodies against them. If you’re later exposed to pneumococcal bacteria, your body can quickly produce those antibodies to fight off the infection before it becomes serious.[1]

The conjugation to the CRM197 protein enhances the immune response, especially in young children. This makes the vaccine more effective at preventing pneumococcal disease than older vaccines that used the polysaccharide alone.

Who is this vaccine for?

The pneumococcal polysaccharide serotype 19A conjugate vaccine is typically included in vaccines recommended for:

  • Infants and young children as part of their routine vaccination schedule
  • Adults 65 years and older
  • People with certain medical conditions that increase their risk of pneumococcal disease

Specific recommendations may vary by country and individual risk factors. Your healthcare provider can advise if this vaccine is appropriate for you or your child.[2]

How effective is it?

Studies have shown that pneumococcal conjugate vaccines containing the 19A serotype are highly effective at preventing invasive pneumococcal disease caused by this strain. For example, research indicates these vaccines can reduce the risk of invasive pneumococcal disease caused by vaccine serotypes by over 90% in children.[3]

In adults 65 and older, the vaccine has been shown to be effective in preventing pneumococcal pneumonia and invasive pneumococcal disease caused by the included serotypes.[4]

Is it safe?

Pneumococcal conjugate vaccines, including those with the 19A serotype, have been extensively studied and have a good safety profile. Common side effects are generally mild and may include:

  • Pain, redness, or swelling at the injection site
  • Mild fever
  • Irritability in children
  • Fatigue
  • Headache
  • Muscle pain

Serious allergic reactions are rare but possible, as with any vaccine. Your healthcare provider can discuss the benefits and risks based on your individual situation.[5]

How is it administered?

The pneumococcal polysaccharide serotype 19A conjugate vaccine is given as an injection, typically in the muscle of the upper arm or thigh. It’s often administered as part of a combination vaccine that protects against multiple pneumococcal serotypes.

The number of doses and schedule can vary depending on age and risk factors. For example:

  • Infants usually receive a series of doses as part of their routine vaccinations
  • Adults 65 and older typically receive a single dose
  • People with certain health conditions may need additional doses

Your healthcare provider will determine the appropriate vaccination schedule for you or your child.[6]

Ongoing research

Researchers continue to study pneumococcal vaccines to improve their effectiveness and expand protection. Some areas of ongoing research include:

  • Developing vaccines that cover even more pneumococcal serotypes
  • Studying the long-term effectiveness of these vaccines
  • Investigating the impact of widespread vaccination on pneumococcal disease rates in communities
  • Evaluating the potential need for booster doses in different populations

This ongoing research helps ensure that pneumococcal vaccines, including those targeting the 19A serotype, continue to provide optimal protection against pneumococcal infections.[7]

Study Aspect Details
Populations studied Infants, children, adolescents, adults 18-64 with risk factors, adults 60+ years
Main outcomes measured Safety, tolerability, immunogenicity, vaccine effectiveness
Immune response markers Opsonophagocytic activity (OPA), Immunoglobulin G (IgG) levels
Safety assessments Local and systemic reactions, serious adverse events
Comparator vaccines 23-valent pneumococcal polysaccharide vaccine (PPSV23), 13-valent pneumococcal conjugate vaccine (PCV13)
Study designs Randomized, controlled, multi-country, phase II/III trials
Key serotypes 19A and others included in multi-valent conjugate vaccines

FAQ

  • What is the main purpose of these clinical trials? The main purpose is to evaluate the safety, tolerability, and immunogenicity (immune response) of pneumococcal conjugate vaccines containing serotype 19A in different populations, including adults, children, and those at higher risk for pneumococcal disease.
  • What age groups are being studied in these trials? The trials cover a wide range of age groups, including infants as young as 2 months old, children and adolescents at higher risk for pneumococcal disease, adults aged 18-64 with increased risk factors, and older adults aged 60 years and above.
  • How is the immune response measured in these studies? The immune response is typically measured through blood tests that look at antibody levels, specifically opsonophagocytic activity (OPA) and immunoglobulin G (IgG) levels against the vaccine serotypes. These are assessed before and after vaccination to determine the vaccine's ability to stimulate an immune response.
  • What are some of the safety measures being evaluated? Safety measures include monitoring for local injection site reactions, systemic reactions, serious adverse events, and any unexpected side effects. Participants are typically followed for a period after vaccination to assess both short-term and longer-term safety outcomes.
  • Are these vaccines being compared to existing pneumococcal vaccines? Yes, some trials compare the new pneumococcal conjugate vaccines to existing vaccines like the 23-valent pneumococcal polysaccharide vaccine (PPSV23) or the 13-valent pneumococcal conjugate vaccine (PCV13) to assess relative safety and immunogenicity.

Ongoing Clinical Trials on Pneumococcal Polysaccharide Serotype 19A 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 disease: Infections caused by Streptococcus pneumoniae bacteria, which can lead to conditions such as pneumonia, meningitis, and bloodstream infections.
  • Conjugate vaccine: A type of vaccine that joins a weak antigen to a strong antigen to enhance the immune response, typically used for bacterial diseases.
  • Serotype: A distinct variation within a species of bacteria, in this case referring to different strains of Streptococcus pneumoniae.
  • CRM197: A non-toxic mutant of diphtheria toxin used as a carrier protein in conjugate vaccines to enhance the immune response.
  • Immunogenicity: The ability of a substance, such as a vaccine, to provoke an immune response in the body.
  • 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.
  • Immunoglobulin G (IgG): The most common type of antibody found in blood circulation, playing a crucial role in the body's immune response.
  • Geometric mean titer (GMT): A way of expressing average antibody levels in a group, calculated using the geometric mean of individual titers.
  • Adverse event (AE): Any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medical treatment or procedure.
  • Vaccine effectiveness (VE): A measure of how well a vaccine prevents disease in real-world conditions, often expressed as a percentage reduction in disease incidence among vaccinated individuals.

References

  1. http://clinicaltrials.eu/trial-id/2022-501519-15-00
  2. http://clinicaltrials.eu/trial-id/2022-501988-40-00
  3. http://clinicaltrials.eu/trial-id/2022-502791-22-01
  4. http://clinicaltrials.eu/trial-id/2022-503144-40-00
  5. http://clinicaltrials.eu/trial-id/2023-506236-32-00
  6. http://clinicaltrials.eu/trial-id/2023-506449-40-00
  7. http://clinicaltrials.eu/trial-id/2023-507293-40-00