Synflorix

Quick links to important sections

Synflorix

Selected form

Method of action: Vacciness

Treatment option:

Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Synflorix

Property Description
Active Ingredients Pneumococcal Polysaccharides conjugated to Carrier Proteins
Form Suspension for injection
Pharmacological Class Immunological Agent / Vaccine (ATC J07AL52)
Common Use Active Immunisation (Prevention)
Origin Biologic / Subunit Conjugate Vaccine

What Type of Medical Product is Synflorix?

Synflorix is officially identified as a Pneumococcal Polysaccharide Conjugate Vaccine (Adsorbed), fundamentally classified as an Immunological Agent used for active preparation of the immune system. Its pharmaceutical form is a turbid white suspension for injection, distinguishing it as a biologic product intended for administration via the intramuscular route. The vaccine falls within the high-level pharmacological class of Vaccines, specifically those targeting pneumococcal infections (ATC Code J07AL52).

Understanding the Composition: 10-Valent and Conjugated

The structure of Synflorix is that of a complex combination product known for its 10-valent structure, incorporating purified capsular Polysaccharides from ten specific serotypes of Streptococcus pneumoniae. These bacterial polysaccharides are chemically linked, or conjugated, to various Carrier Proteins—including Protein D (derived from Non-Typeable Haemophilus influenzae), Tetanus Toxoid, and Diphtheria Toxoid—to enhance the immune response. The vaccine incorporates multiple carrier proteins to improve immunogenicity, especially in infants. The vaccine is designated as adsorbed because the active components are attached to the adjuvant, Aluminium phosphate, which helps stimulate the body’s defenses and stabilizes the formulation within the aqueous base. The inclusion of Protein D as a carrier is a differentiating feature clinically noted for supporting immune response.

Primary Function: Establishing Active Immunisation

The primary function of Synflorix is to establish Active Immunisation by stimulating the immune system to create its own defense against the ten specific serotypes included in the product. This immunological training generates durable antibodies and memory cells, preparing the body to swiftly recognize the target bacterial components upon natural exposure. The purpose of this entire biological process is prevention, typically used in public health settings, serving to protect the individual by enabling immunological readiness before potential infection occurs. This type of preparation results in the generation of functional antibodies.

Regulatory References

  1. World Health Organization (WHO) Prequalification

What side effects are possible with Synflorix ?

Possible Side Effects and Safety Information

This section describes the officially documented adverse effects and safety characteristics of Synflorix, based strictly on authoritative government regulatory sources.

The safety profile is formally organized by the frequency of occurrence and the physiological system affected.

Frequency-Classified Adverse Reactions

The most frequently documented reactions are classified as Very Common (ge 1/10). These typically include local effects such as pain, redness, and swelling at the injection site, as well as systemic reactions like fever (ge 38^circC), drowsiness, irritability, and loss of appetite. Less frequent, Common effects include the formation of induration at the injection site. Uncommon reactions may involve diarrhoea, vomiting, rash, and pruritus.

Systemic and Serious Reactions

Adverse effects are grouped by System-Organ Class (SOC) in regulatory documents, involving the Nervous System (e.g., drowsiness, convulsions), the Gastrointestinal System, and Skin and Subcutaneous Tissue (e.g., rash). Rare and clinically significant events documented in official labeling include convulsions (including febrile convulsions), Angioedema, and the occurrence of Kawasaki disease.

Safety Constraints and Population-Specific Notes

Administration is officially contraindicated in individuals with known hypersensitivity to any component of the vaccine. Regulatory texts advise postponement of administration in subjects with an acute severe febrile illness. The official label includes specific cautions for certain populations, noting a documented potential risk of apnoea (temporarily stopping breathing) in very premature infants (le 28 weeks gestation), which may require post-administration monitoring. Additionally, the label notes that reactogenicity, particularly injection site reactions and fever, may be more pronounced following the booster dose given to older children.

Overdose and Emergency Response

Overdose and when to seek help

The official regulatory documents indicate that no case of overdose has been reported in the clinical experience with Synflorix. Due to the vaccine's classification as an immunological agent, the official guidance for severe events focuses on managing acute systemic reactions.

Overdose Scope Regulatory Statement
Documented Manifestation No case of overdose has been reported.
Severe Outcome Risk Anaphylactic reaction is a potential life-threatening event.
Population-Specific Note Very premature infants (born le 28 weeks of gestation) have a documented risk of apnoea.

Official Emergency Statements:

  • Seek immediate medical attention for symptoms indicative of a severe allergic reaction, such as swelling of the limbs, face, or throat, or sudden, severe weakness or collapse.
  • Appropriate medical treatment and supervision must be readily available to manage the rare risk of a severe systemic event like anaphylaxis following administration.
  • Mandatory respiratory monitoring for 48–72 hours must be considered for very premature infants due to the potential risk of apnoea.
  • No specific antidote is known or described in the regulatory prescribing information.

Connection to the overall overdose profile: The regulatory profile is defined by the official statement of no reported cases, shifting the emergency focus toward managing rare, severe systemic reactions. This requires patients to contact emergency services immediately upon noticing the onset of life-threatening symptoms, ensuring prompt access to supportive medical care as mandated by official labeling.

Therapeutic Uses of Synflorix

Synflorix is considered relevant for use in infants and children for addressing conditions related to specific strains of pneumococcus. The primary focus is on preventative support, which helps ease the overall symptom load associated with severe infections.

This agent is commonly used across conditions presenting with acute episodes and systemic imbalance, such as meningitis (a systemic infection), septicaemia (blood poisoning), and bacteraemia. This preventative support helps maintain a sense of stability when symptoms are more noticeable, supporting the patient during difficult episodes.

The use of this agent is also relevant for managing symptoms that interfere with daily comfort, associated with localized infections. It is commonly used across conditions presenting with acute episodes, including pneumonia and acute otitis media (AOM), which involve symptoms related to inflammatory or irritative states.

The application is relevant in clinical settings that involve acute or unstable symptom patterns, including the use for high-risk pediatric groups like premature infants and children with chronic underlying conditions like splenic dysfunction.

Quick Fact: Relief for Systemic and Respiratory Symptoms (Through Prevention)

Regulatory References

  1. European Medicines Agency (EMA) overview

Eligibility and Restrictions for Use

The eligibility for Synflorix is strictly defined by regulatory bodies for use in a specific pediatric age range and is subject to documented population-specific rules and contraindications.

Official Eligibility and Contraindications

Population Status Regulatory Rule (Official Labeling)
Approved Age Range Infants and children from 6 weeks up to 5 years of age.
Absolute Contraindication Individuals with known hypersensitivity to any component of the vaccine, including active substances, excipients, or carrier proteins.
Conditional Use (Postponement) Administration must be postponed for subjects suffering from an acute severe febrile illness.
Conditional Use (Caution) Use requires caution in children with thrombocytopenia or any coagulation disorder.
Use Not Established Safety and efficacy have not been established for children over 5 years of age, adolescents, or adults.

Special Population Considerations

Synflorix is often administered to high-risk pediatric groups, such as those with Human Immunodeficiency Virus (HIV) infection, sickle cell disease, or splenic dysfunction. However, regulatory documents state that when administering the primary series to very premature infants (born at leq 28 weeks of gestation), the risk of apnoea and the need for respiratory monitoring for 48–72 hours must be considered. Furthermore, children with impaired immune responsiveness may have a reduced antibody response to vaccination.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Synflorix is a vaccine whose interaction profile is defined by its use with other vaccines and the potential for a reduced immune response when combined with certain medications.


Co-Administration with Other Vaccines

Synflorix can be given at the same time as several other vaccines, including those for Diphtheria, Tetanus, Pertussis (acellular), Hepatitis B, Inactivated Polio, Haemophilus influenzae type b, Measles, Mumps, Rubella, and Varicella. A critical constraint is that different injectable vaccines administered simultaneously must always be given at separate injection sites.


Exposure and Immune Response Modifiers

Substance Category Interaction Statement
Immunosuppressive Medicinal Products Patients receiving immunosuppressive treatment may not generate an adequate immune response to the vaccine (reduced efficacy).
Prophylactic Antipyretics Clinical data suggest that the prophylactic use of paracetamol (before or immediately after vaccination) might reduce the immune response to Synflorix. The clinical relevance is currently unknown.

Timing and Population-Specific Constraints

  • Timing Requirement: A minimum interval of 8 weeks is required between the administration of Synflorix and the 23-valent pneumococcal polysaccharide vaccine.
  • Population Note: Children with impaired immune responsiveness due to conditions like HIV infection or ongoing immunosuppressive therapy may have a reduced antibody response to the vaccine. Inconsistent results have been observed for the immune response to the inactivated poliovirus type 2 component when co-administered; the clinical relevance is not known.

Mechanism of Action

Eliciting T-Cell Dependent Immune Activation

Synflorix functions by presenting bacterial polysaccharide antigens linked (conjugated) to a carrier protein to the host's immune system. This targeted delivery mechanism engages Antigen-Presenting Cells (APCs) and T-helper cells ( CD4^+ T-cells), thereby initiating the complex molecular cascade promoting a T-cell dependent immune response. This process supports the generation of immunological memory, which involves the long-term persistence of antigen-specific lymphocytes.


Driving the Humoral Response and Functional Antibody Production

The T-cell activation pathway supports the differentiation of B-lymphocytes into specialized plasma cells, leading to the production of specific IgG antibodies. These antibodies coat the bacterial cell surface (a process called opsonization), which acts as a molecular marker. The resulting physiological effect is the initiation of phagocytosis—the destruction of the marked bacteria by immune cells—which demonstrates the functional consequence of the antibody action on the pathogen's surface structures.

Dosage and Administration Information

Official Administration Guidelines

The use of Synflorix is governed by specific, fixed-protocol instructions, ensuring consistent administration of the product. The vaccine is indicated for children aged 6 weeks up to 5 years and is not authorized for use in older children or adults.

Administration Scope

Feature Official Instruction (Label-Based)
Route of administration: Intramuscular (IM) injection only. It must not be administered intravascularly, intradermally, or subcutaneously.
Dosing schedule: A fixed volume of 0.5 mL is used for every injection, regardless of the child's age or weight.
Preparation requirements: The suspension must be well shaken immediately prior to use until it becomes a uniform, turbid white liquid.

Age-Specific Vaccination Schedule

The total number of doses and timing intervals depend on the child's age when the first dose is given. The full course should be completed with Synflorix. Schedules may vary by region based on official immunization programs.

Recent Clinical Evidence

Research evidence / Overview of Studies for Synflorix

This section outlines the research that has been conducted on Synflorix, describing the types of studies, the populations they examined, and the outcomes that were monitored. The findings describe group patterns observed in research settings, not personal outcomes, and research does not determine whether an individual will respond similarly.

Evidence for Use in Preventing Invasive Pneumococcal Disease (IPD) and Respiratory Infections

Research exploring the product's scope for immunization against pneumococcal infections has been conducted through large-scale, controlled clinical trials (RCTs), as well as observational surveillance programs. These studies were conducted in large groups of healthy infants and young children. Researchers examined outcomes such as the incidence of culture-confirmed Invasive Pneumococcal Disease (IPD), hospital-diagnosed pneumonia, and episodes of Acute Otitis Media (AOM). Regulatory assessments have described the evidence related to IPD using the coarse grading label of High. The observed effect related to AOM and pneumonia appears to be substantially lower than the effect observed for IPD.

Immunological Studies and Serotype Response

The research included laboratory studies that focused on immunological outcomes, examining the development of immune markers related to the vaccine components. Studies monitored the generation of serotype-specific antibody levels and functional antibodies across all ten serotypes contained in the product. Research also explored whether the product generated cross-reactive responses against a related serotype, 19A. A finding reported in the research is that the measured magnitude of the functional immune response was lower for serotypes 1 and 5 when compared to the immune responses observed against the other eight serotypes.

Studies in High-Risk Pediatric Groups

Research has also explored the immune response generated in specific patient populations associated with a higher risk of pneumococcal disease. These were primarily immunological trials conducted in children with underlying conditions such as HIV infection, sickle cell disease, or splenic dysfunction, and in stable preterm infants. The available evidence related to these patient groups was described as moderate, and the trials reported how immune markers developed in these specific cohorts following either standard or modified dosing schedules.

Documented Research Gaps and Uncertainties

The evidence base highlights what is still uncertain regarding the product's research profile: Data for certain high-risk groups remain insufficient, and the results apply only to the limited cohorts studied. It is not yet clear how the observed variability in immune response for serotypes 1 and 5 was associated with differences in disease incidence caused by those specific serotypes. Furthermore, evidence is limited regarding protection against pneumococcal serotypes not contained in the vaccine formulation, and long-term outcomes are not fully established.

Frequently Asked Questions (FAQ)

Common questions about Synflorix (FAQ)


Q: Which specific serotypes of Streptococcus pneumoniae are included in Synflorix?

Regulatory documents list the specific serotypes of Streptococcus pneumoniae that Synflorix is formulated to protect against. This 10-valent vaccine contains polysaccharides from the following ten serotypes: 1, 4, 5, 6B, 7F, 9V, 14, 18C, 19F, and 23F.

Q: How is Synflorix different from Prevnar 13 (PCV13) regarding the number of serotypes covered?

Official product information describes Synflorix as a 10-valent vaccine, which means it targets ten specific strains (serotypes) of Streptococcus pneumoniae. For comparison, other vaccines like Prevnar 13 are known to be 13-valent, covering thirteen strains. The difference relates to the specific serotypes included in the respective formulations.

Q: How is Synflorix different from the older PCV7 vaccine?

Regulatory documentation describes Synflorix as a 10-valent vaccine, which protects against ten serotypes of Streptococcus pneumoniae. The older PCV7 vaccine, in comparison, was formulated to protect against seven serotypes.

Q: Why might a public health schedule choose Synflorix over a different pneumococcal vaccine?

Synflorix contains specific components that differentiate it from other pneumococcal vaccines. Official regulatory summaries highlight the use of Protein D from H. influenzae as a unique carrier protein for several of its components. These distinguishing features are described in regulatory documents as a unique characteristic of the product's formulation.

Q: Is Synflorix considered a routine childhood immunization in most programs?

Official documents describe the vaccine's use 'as part of a routine infant immunisation programme.' This framing suggests the product is included in recommended public health schedules in the regions where it is registered.

Q: Does Synflorix contain live or inactivated components?

Synflorix is classified as a Pneumococcal Polysaccharide Conjugate Vaccine. This means it is made from purified bacterial polysaccharides and carrier proteins, and therefore does not contain live bacteria capable of causing the disease.

Q: Can Synflorix cause the disease it is meant to prevent?

Because the vaccine is a conjugate vaccine composed of purified, non-living parts of the bacteria, it does not contain the live germ. This composition means the vaccine cannot cause the invasive pneumococcal disease it is meant to prevent.

Q: Will Synflorix protect against all types of pneumonia or meningitis?

The vaccine is indicated to provide active immunisation only against diseases caused by the ten specific Streptococcus pneumoniae serotypes it contains. Therefore, the vaccine does not protect against all types of pneumonia or meningitis caused by other pathogens.

Q: Does the vaccine protect against bacteria other than Streptococcus pneumoniae?

The official therapeutic indications state that Synflorix is intended only for immunisation against disease caused by Streptococcus pneumoniae. It is not indicated for protection against other types of bacteria or pathogens.

Q: What does the medical term 'invasive pneumococcal disease' mean in simple language?

This medical term (IPD) is used in regulatory documents to describe severe infections caused by Streptococcus pneumoniae. These serious conditions include sepsis (blood infection), meningitis (brain/spinal cord infection), and bacteraemia (bacteria in the blood).

Q: What are the signs of a severe allergic reaction to Synflorix that require immediate attention?

Severe allergic reactions are rare, but their signs are formally documented in safety information. These signs can include a raised, itchy rash (hives), swelling of the face, throat (Angioedema) causing difficulty breathing, or sudden collapse.

Q: Can children with a weakened immune system or underlying chronic illness receive Synflorix?

Regulatory documents state that the vaccine is indicated for use in certain high-risk children, such as those with HIV infection or sickle cell disease. However, the official information also indicates that individuals who have impaired immune responsiveness may generate a reduced antibody response to the vaccine.

Q: Can a child switch to a different pneumococcal vaccine, like PCV13, if they started with Synflorix?

Regulatory guidance states that it is recommended subjects who receive a first dose of Synflorix complete the full vaccination course using the same product.

Q: How long does the protection from Synflorix generally last?

Studies indicate that Synflorix generates immunological memory in the body, which is the mechanism for long-term protection. However, official regulatory summaries note that specific long-term outcome data related to disease prevention are not fully established.

Q: Are there any food or drink interactions reported for Synflorix?

Official regulatory product information outlines specific interactions with certain medicinal products, such as immunosuppressants or prophylactic fever-reducing medicines. However, the documentation does not report or discuss any known interactions with food or drink.

Q: What are the non-active ingredients or excipients in the vaccine?

Official product information lists the vaccine's non-active components (excipients). These include Aluminium phosphate, which acts as an adjuvant to help stimulate the body's defenses, as well as Sodium chloride and Water for injections.

Q: Does Synflorix contain thimerosal?

According to the official regulatory product information, Thimerosal is not listed among the excipients contained in the vaccine formulation.

Q: Does the Synflorix vaccine require a prescription?

Synflorix is formally classified as a medicinal product that is subject to medical prescription.

How should Synflorix be stored and disposed of?

How to Store and Dispose of Synflorix

Synflorix (Pneumococcal Polysaccharide Conjugate Vaccine, Adsorbed) must be stored under strict conditions to maintain its integrity, as mandated by regulatory labeling.

Condition Requirement
Temperature Range Store in a refrigerator between 2°C and 8°C (36°F and 46°F).
Freezing Do not freeze; the vaccine must be discarded if it has been frozen.
Light Protection Store in the original package to protect from light.

For multidose vials, the product must be used within 28 days after first opening when kept refrigerated. The vaccine should not be used after the expiry date.

All unused product or waste material must be disposed of in accordance with local requirements and must not be discarded via wastewater or household waste. The medicine must be kept out of the sight and reach of children.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

Available in countries:

Equivalent of Synflorix  found in:

A-Z Index: