What Avaxim 160 Treats: Main Uses and Benefits

Primary Prophylaxis Against Acute Viral Hepatitis A

Avaxim 160 is used across therapeutic domains where short-term symptom management is appropriate. The primary therapeutic use is for prophylaxis against this acute liver infection in susceptible adolescents and adults. This supports the patient during difficult episodes by easing distress and may assist with maintaining functional stability.

Prevention of Severe Systemic and Hepatic Symptoms

The vaccine's use is relevant for easing symptoms that interfere with daily functioning, and is applied in addressing the severe symptom clusters of acute hepatitis. This may include systemic manifestations like profound fatigue, high fever, and gastrointestinal symptoms related to systemic imbalance. It is considered relevant in contexts involving heightened systemic burden, as it may contribute to easing the overall symptom load associated with severe hepatic manifestations like jaundice in vulnerable groups.

Strategic Protection for High-Risk Individuals and Travelers

Avaxim 160 is commonly used across conditions presenting with acute episodes in high-risk scenarios, such as preparation for international travel to endemic regions. It may assist with addressing potential symptomatic burden for susceptible individuals, particularly those with pre-existing chronic liver disease or those in occupations with elevated exposure risk, assisting with maintaining functional stability.

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Quick Fact: Symptomatic Relief Domains

Avaxim 160 is applied in clinical settings that involve acute or unstable symptom patterns, relevant for managing symptoms that create noticeable physiological strain and supporting patients during episodes of heightened discomfort by easing the overall symptom load.

Eligibility Scope

Populations for whom use is allowed (as stated in label):

• Susceptible adolescents aged 16 years and above (EU/UK labelling).
• Susceptible adults (no upper age limit specified for standard indication).
• Susceptible persons 12 years of age and older (Canadian labelling).

Populations for whom use is not recommended (if applicable):

• Children less than or equal to 15 years of age (EU/UK, due to insufficient data for the 160U formulation).
• Pregnant individuals (unless use is clearly necessary, following a risk/benefit assessment).

Populations for whom use is contraindicated:

• Individuals with systemic hypersensitivity to the active substance, any excipient, or neomycin (a manufacturing trace) and those with a history of severe allergic reaction following a previous dose.

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Condition-Specific and Conditional Eligibility

Age-related eligibility rules:

• The minimum approved age is 16 years in Europe/UK and 12 years in Canada/Australia, reflecting regulatory differences for this specific formulation.

Condition-specific eligibility rules:

• Vaccination must be postponed in the presence of an acute severe febrile illness.
• Use must be considered with care in patients with liver disease, as formal studies have not been conducted in this population.
• The immune response could be impaired in patients with immunodeficiency states or those receiving immunosuppressive treatment.
• Caution is required for individuals with bleeding disorders or thrombocytopenia due to the injection method.

Pregnancy and lactation eligibility status (if explicitly documented):

• Pregnancy: Not recommended unless the benefit clearly outweighs the potential risk.
• Lactation (Breastfeeding): Use is possible during breastfeeding, but caution is advised.

Official Eligibility Summary

Regulatory documents establish that Avaxim 160 is restricted to older adolescents and adults, with absolute contraindication for individuals with known allergies to vaccine components, including neomycin. Eligibility is conditionally constrained for those with acute illness, liver disease, or impaired immune function where the vaccine response may be limited or unstudied.

Interactions with other medicines and products

The official regulatory profile for Avaxim 160, an inactivated viral vaccine, is uniquely defined by constraints necessary to ensure a maximal immune response and maintain physical compatibility with other medicinal products.

Pharmacodynamic Interactions The most significant interactions are pharmacodynamic in nature. Official documents state that immunosuppressive treatment or existing immunodeficiency states are documented to potentially induce a decrease in the immune response to the vaccine. Separately, if immunoglobulins are administered concurrently, resulting antibody titres may be lower than those achieved when the vaccine is administered alone; however, overall seroprotection rates are not documented to be modified by this combination.

Administration and Separation Requirements Avaxim 160 must not be mixed with any other vaccine or medicinal product in the same syringe due to physical incompatibility constraints. This mandatory restriction requires that all co-administered products be given in separate injection sites using separate syringes and needles. This spatial separation rule applies to combinations with other vaccines, including the typhoid polysaccharide vaccine (Typhim Vi) and the live yellow fever vaccine.

Absence of Pharmacokinetic Interactions Regulatory documentation confirms that Avaxim 160 is not associated with known pharmacokinetic interactions involving metabolic pathways (such as CYP enzymes) or drug transporters. The documented interaction profile is focused exclusively on immunological outcomes and physical administration constraints.

Avaxim 160 is an inactivated, adsorbed viral vaccine containing purified Hepatitis A Virus (HAV) antigen from the GBM strain, which is chemically modified by formaldehyde. The HAV antigen is adsorbed onto aluminum hydroxide, serving as an adjuvant to concentrate the antigen at the injection site and promote cellular uptake.

The vaccine's primary biological target is the host immune system within the muscle tissue, specifically antigen-presenting cells (APCs) like dendritic cells and macrophages. The aluminum adjuvant facilitates the recognition and engulfment of the inactivated HAV antigen by these APCs.

Following processing, APCs present the viral epitopes to T-lymphocytes via MHC class II molecules. This receptor-ligand interaction initiates a cascade involving the differentiation and proliferation of CD4+ T helper cells and the activation of B-lymphocytes. B cells, stimulated by T helper cell signals, undergo clonal expansion and differentiate into plasma cells, which are the terminal effector cells. These plasma cells synthesize and secrete anti-HAV Immunoglobulin G (IgG) antibodies that circulate systemically. Concurrently, a population of antigen-specific memory B and T cells is generated. The system-level physiological consequence is the establishment of a state of humoral and cellular immunological memory against the HAV viral capsid proteins.

The administration of Avaxim 160 follows a standardized schedule intended for individuals 16 years of age and above. The vaccine is supplied as a 0.5 mL suspension for injection, containing 160 ELISA Units of the inactivated Hepatitis A virus. The correct procedural method requires the contents of the syringe to be shaken thoroughly prior to administration to ensure the suspension is fully homogenous.

The standardized route of administration is via intramuscular (IM) injection, with the preferred site being the deltoid region of the upper arm. The subcutaneous (SC) route is an alternative strictly reserved for specific patients, such as those with a risk of haemorrhage. The vaccine is forbidden from being administered by the intravascular or intradermal routes, and injection into the buttocks should be avoided.

The complete use pattern involves a two-dose regimen. The primary vaccination consists of a single 0.5 mL dose. To establish the required long-term duration of protection, a second (booster) 0.5 mL dose is required. This booster is typically scheduled 6 to 12 months following the primary injection, though administration is permitted up to 36 months afterward. When given simultaneously with other immunisations, Avaxim 160 must be administered at a separate injection site.

Research Evidence / Overview of Studies for Avaxim 160

Research Evidence for Primary Prophylaxis Against Hepatitis A

Research evaluating Avaxim 160 primarily focuses on its role in active immunisation against the Hepatitis A virus in people who have not been previously exposed. These findings are derived mostly from Randomized Controlled Trials (RCTs) and various Prospective Cohort Studies.

These studies explored the vaccine's ability to stimulate an immune response, a measure known as immunogenicity. The main outcomes research examined were the Seroconversion Rate—the proportion of healthy adults and adolescents who developed levels of anti-HAV antibodies used as correlates of immunity after receiving the vaccine series—and the Geometric Mean Concentration (GMC) of these antibodies.

Studies tracked these antibody levels over defined time intervals and described patterns where participants developed the targeted anti-HAV antibody concentration following the vaccine series. These reported measurements of antibody levels contribute to the body of evidence reviewed by regulators. However, the existing research relies primarily on these antibody levels as a surrogate endpoint, meaning direct evidence on the prevention of clinical disease in large-scale trials is generally limited.

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Studies in Specific Populations with Pre-existing Conditions

Research has explored the immune response generated by the vaccine in specific adult and adolescent groups, including those with certain pre-existing conditions, such as Chronic Liver Disease.

These research efforts primarily used Cohort Studies to compare the antibody response in these individuals against the response observed in healthy control subjects. Studies reported that the immune response pattern in immunocompetent individuals with Chronic Liver Disease was observed to be similar to the response reported in the general population. Data also show patterns related to immune response in other groups, such as those traveling to endemic regions.

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Long-Term Evidence and Durability of Immune Response

Studies have explored the duration of the vaccine's immune effect, focusing on how long the anti-HAV antibody concentrations persist in the blood after the primary vaccination series. Research describes patterns where antibody concentrations typically decrease in the years following the last dose, with persistence observed over defined time intervals. Researchers provide context by estimating how durable the immune response may be, often using mathematical modeling to predict persistence decades beyond the period of direct observation. This type of analysis provides context; however, continuous clinical data tracking over extended periods is limited.

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What the Research Landscape Does Not Yet Address

While research has extensively explored the initial immune response to Avaxim 160, research is ongoing, but definitive, continuously tracked clinical data for antibody persistence beyond approximately 10 to 11 years are not fully established, with longer-term estimates primarily derived from mathematical projections. Research cannot predict whether any single individual will respond similarly to the group patterns observed in these studies.

Key Studies & References

1. WHO position paper on hepatitis A vaccines – October 2022 (Clinical Guidelines and Policy)
2. Advancements in Vaccine Strategies for Chronic Liver Disease Patients: Navigating Post-COVID Challenges and Opportunities (Evidence in Special Populations)

Common questions about Avaxim 160 (FAQ)

Q: Is there a different version of the vaccine for children, and how does it compare to Avaxim 160 U?

A: Official product information states that Avaxim 160 U is intended for adolescents and adults, typically aged 16 years and above. A separate formulation called Avaxim 80 U Pediatric is available for use in children who are not eligible for the 160 U dose.

The difference is in the amount of active ingredient: the pediatric version contains a lower quantity (80 ELISA Units) in the same 0.5 mL volume.

Q: What is the estimated duration of protection after the full two-dose series of Avaxim 160?

A: Studies and official information indicate that anti-Hepatitis A virus antibodies are expected to persist for many years following the complete two-dose schedule. Persistence of protective antibody levels is often referenced in documentation as extending beyond 10 years.

Longer-term estimates are sometimes projected using mathematical models, though continuously tracked clinical data over extended periods are limited.

Q: What symptoms are associated with a very rare, severe allergic reaction to the vaccine?

A: Serious allergic reactions, known as anaphylaxis, are possible but happen very rarely after any vaccine. Patient information outlines symptoms that may include difficulty in breathing, swelling of the face and neck, or a fast heart rate.

Regulatory information notes that if a severe reaction is suspected, seeking immediate attention is essential.

Q: How does Avaxim 160 interact with other medicines a person may be taking?

A: Regulatory documentation confirms that this vaccine is not associated with known interactions involving the body’s metabolic pathways. However, the official profile focuses on the immune response.

If used alongside treatments that suppress the immune system or with immunoglobulins, the vaccine's protective response may be reduced. The requirement for physical separation of the vaccine from other co-administered products is also a documented constraint.

Q: What are the excipients (non-active ingredients) in Avaxim 160?

A: The non-active components, or excipients, listed in the official documents include purified water, aluminium hydroxide (used as an adjuvant to help the immune response), and traces of substances from the manufacturing process, such as formaldehyde and neomycin.

The formulation also contains 2-phenoxyethanol and trace amounts of ethanol and phenylalanine which are noted in the product information.

Q: How long does it takes for a potential injection site reaction like pain to go away?

A: Official safety data indicates that local and systemic reactions, such as pain at the injection site, are generally mild.

These reactions are typically confined to the first few days following the vaccination and are described as resolving spontaneously. They are also less frequently reported after the booster dose than after the primary dose.

Q: What are the current official recommendations for using Avaxim 160 related to travel?

A: The purpose of the vaccine is active immunisation for those at risk of exposure to the Hepatitis A virus.

Official recommendations often specify its use for non-immunized adults and adolescents who are planning travel to regions where the virus is common, which places them at a higher risk of exposure.

Q: What should the vaccine liquid look like, and what if it appears discolored or contains particles?

A: Before use, the Avaxim 160 liquid is expected to be a sterile, whitish, cloudy suspension and should be thoroughly shaken to ensure homogeneity.

Regulatory information states that the product is designated for discard if unexpected foreign particles are visible or if the liquid appears discolored.

Q: Are there specific groups, like healthcare workers or food handlers, for whom Avaxim 160 is officially recommended?

A: Regulatory and public health bodies often provide specific recommendations for certain high-risk occupational groups at risk of exposure to the virus.

Examples listed may include healthcare workers, food handlers, sewage and water treatment personnel, and nursery personnel.

Q: What is the recommended period to wait before vaccination if someone is recovering from a serious illness?

A: Official documentation states that vaccination should be postponed until a person has recovered from any acute severe febrile illness, meaning an illness accompanied by a high temperature.

The regulatory documents do not specify a minimum recovery period for non-febrile or serious chronic illnesses.

Q: Can Avaxim 160 be used as a booster if the first vaccination was a different brand of Hepatitis A vaccine?

A: While the regulatory documentation primarily addresses the two-dose regimen of Avaxim 160, relevant clinical literature has indicated that Avaxim can be used as a booster dose.

This is applicable even if the individual was initially vaccinated with a different Hepatitis A-containing product.

Q: How soon after the initial injection can a person expect to have protective antibodies?

A: Studies have shown that immunity develops quickly after the first injection.

According to official data, more than 90% of healthy adults and adolescents demonstrate protective antibody levels within 14 days of vaccination, increasing to almost 100% one month after the first dose.

Q: Does the vaccine contain small amounts of phenylalanine, and why is this noted?

A: Yes, official product information confirms that the vaccine contains a trace amount of phenylalanine (10 micrograms) in each dose.

This is noted as a precaution because phenylalanine may be harmful to people who have the rare genetic disorder phenylketonuria (PKU).

Q: Does Avaxim 160 contain any trace amounts of alcohol (ethanol)?

A: Regulatory documents state that the vaccine does contain a small amount of anhydrous ethanol (alcohol), approximately 2 mg in each dose.

This minimal amount of alcohol is described in the official text as not having any noticeable effects on the recipient.

Q: Can Avaxim 160 be used in people who have already been exposed to Hepatitis A but do not have symptoms yet?

A: Regulatory warnings state that if the vaccine is administered when an individual is already in the incubation period of the disease (meaning they may have been infected but are not yet showing symptoms), it may have no effect on preventing the development of Hepatitis A.

The official documentation emphasizes that the primary role of the vaccine is active immunisation for prevention.

Q: Does Avaxim 160 contain potassium or sodium, and in what amounts?

A: Official documentation confirms that the vaccine contains both potassium and sodium.

However, the amounts are very small, considered less than 1 mmol per dose. For this reason, the product is officially described as essentially 'potassium-free' and 'sodium-free.'

Q: Is there any information on how Avaxim 160 affects the ability to drive or use machines?

A: Official product information states that the vaccine is unlikely to produce an effect on a person's ability to drive or use machines.

If any side effects that could temporarily impair function are experienced, official guidance indicates that caution should be exercised.

How to Store and Dispose of Avaxim 160 U

Avaxim 160 U must be stored under specific, mandatory conditions to maintain its stability and effectiveness, as documented in official regulatory labeling.

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Storage Requirements

• Refrigeration: The vaccine must be kept in a refrigerator at a temperature range of 2 C to 8 C.
• Freezing: Do not freeze the product; it must be discarded if it has been frozen.
• Light Protection: Store the vaccine in its original packaging to protect it from light.
• Child Safety: Keep the product strictly out of the sight and reach of children.
• Expiry: Do not use the vaccine after the expiry date printed on the carton.

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Disposal Instructions

Any unused medicinal product or waste material should not be disposed of via wastewater or household waste. Disposal must be carried out in accordance with local requirements, typically by taking the unwanted medicine to a pharmacist for proper disposal.