Avaxim80 unit/prefilled syringe

Avaxim is indicated for active immunization against infection caused by hepatitis A virus (HAV).

Established / Approved Uses

• Routine immunization of children starting at 12 months of age, per national and international childhood immunization schedules.
• Pre-exposure protection for adults and children ≥12 months of age who are at increased risk of HAV infection, including travelers to countries with high or intermediate endemicity of hepatitis A.
• Individuals with chronic liver disease (including hepatitis B or hepatitis C infection), who are at higher risk of severe outcomes if infected with HAV.
• Men who have sex with men, users of injection and non-injection drugs, and persons with occupational risk of exposure (e.g., laboratory workers handling HAV).
• Persons with clotting-factor disorders and household/close contacts of international adoptees from HAV-endemic countries.

Guideline-Supported / Outbreak Use

• Post-exposure prophylaxis in healthy persons 12 months-40 years of age recently exposed to HAV, ideally within 2 weeks of exposure.
• Use during community hepatitis A outbreaks as directed by public health authorities.

Avaxim does not provide protection against hepatitis caused by other agents (e.g., hepatitis B, C, E) and will not prevent disease in a person already incubating HAV infection at the time of vaccination.

Each dose of Inactivated Hepatitis A vaccine contains a purified, formalin-inactivated (killed) strain of hepatitis A virus grown in human diploid cell culture, adsorbed onto an aluminum hydroxide adjuvant. Depending on the manufacturer and presentation (pediatric 0.5 mL vs. adult 1 mL), the formulation may also contain trace amounts of neomycin (from the cell-culture process), a preservative such as 2-phenoxyethanol in multi-dose presentations, and other inactive excipients (e.g., amino-acid supplement, polysorbate 20). Exact antigen content, expressed in ELISA units, varies by brand and age-appropriate formulation.

Avaxim is a sterile suspension for intramuscular injection containing whole, inactivated (non-live) hepatitis A virus antigen. Because the virus is killed rather than live-attenuated, Avaxim cannot cause hepatitis A infection or replicate in the body. It works by stimulating the immune system to produce protective antibodies against HAV, closely mimicking the immunity produced by natural infection without the risk of disease. It is supplied as a ready-to-use suspension in single-dose vials or prefilled syringes, available in separate pediatric and adult dose strengths.

Avaxim belongs to the therapeutic class of viral vaccines, specifically inactivated (killed) monovalent viral vaccines used for active immunoprophylaxis against hepatitis A virus infection.

Inactivated Hepatitis A vaccine contains hepatitis A virus antigen inactivated with formaldehyde and adsorbed to an aluminum-based adjuvant. After intramuscular administration, the adjuvant promotes a depot effect and enhanced antigen presentation, stimulating both humoral (antibody) and cell-mediated immune responses directed against HAV surface proteins.

Following a two-dose primary series, protective anti-HAV antibody levels develop in nearly all healthy vaccinees, with seroprotection achieved in more than 95% of recipients after the first dose and close to 100% after completion of the series. The booster (second) dose is important for inducing long-term, likely lifelong, immune memory. Because the virus in Inactivated Hepatitis A vaccine is fully inactivated, it cannot replicate, cause active infection, or revert to a virulent form.

Avaxim should be administered only by intramuscular injection, using the deltoid muscle in adults and older children or the anterolateral thigh in infants/young children. Do not inject into the gluteal region, as this may reduce vaccine efficacy. Shake well before use to obtain a uniform, slightly turbid white suspension; inspect visually for particulate matter or discoloration and discard if either is present. Appropriate medical treatment for managing acute anaphylactic reactions must be immediately available whenever Avaxim is administered.

Avaxim can generally be administered concomitantly with other routinely recommended vaccines (e.g., hepatitis B, typhoid, yellow fever, MMR, tetanus-containing vaccines), provided separate syringes and separate injection sites are used.

• Immune globulin (IG): Concomitant administration of IG with Avaxim may blunt the resulting antibody titer somewhat, though it does not appear to reduce protective efficacy; when both are indicated, they should be given at different injection sites.
• Immunosuppressive therapy/immunocompromising conditions: Patients on immunosuppressive drugs or with immunocompromising conditions may have a diminished antibody response to Avaxim; vaccination is still generally recommended, but serologic confirmation of response may be considered in select high-risk patients.

No clinically significant interactions with commonly used oral medications have been established for Avaxim.

Avaxim is generally well tolerated. Because the vaccine virus is inactivated, it cannot cause hepatitis A infection.

Very Common / Common

• Injection-site pain, soreness, redness, or swelling (the most common reaction)
• Headache
• Fatigue or malaise
• Low-grade fever
• In infants and young children: irritability, drowsiness, and temporary loss of appetite

Uncommon/Rare

• Gastrointestinal symptoms (nausea, vomiting, diarrhea, loss of appetite)
• Syncope (fainting), particularly in adolescents - observation for about 15 minutes after injection is advised
• Rare hypersensitivity reactions, including anaphylaxis (see Contraindications)

Most side effects of Avaxim are mild and resolve within 1-2 days without treatment.

Pregnancy: There are no adequate and well-controlled studies of Avaxim in pregnant women. As it contains inactivated (killed) virus, the theoretical risk to the fetus is considered low; however, Avaxim should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus. A physician should be consulted before vaccination during pregnancy.

Lactation: It is not known whether components of Avaxim are excreted in human milk. Because it is an inactivated vaccine, it is generally considered compatible with breastfeeding, but a physician should be consulted before use in breastfeeding mothers.

The following precautions apply to Avaxim:

• Vaccination should be deferred in persons with moderate-to-severe acute illness (with or without fever) until the condition improves; minor illnesses such as a mild cold are not a reason to defer.
• Appropriate medical treatment and supervision must always be available in case of a rare anaphylactic reaction.
• Syncope can occur after vaccination, especially in adolescents; observing the recipient for approximately 15 minutes after injection is recommended.
• Immunocompromised individuals (e.g., HIV infection, immunosuppressive therapy) may have a reduced antibody response to Avaxim; vaccination is still generally recommended given their heightened risk from natural HAV infection.
• As with any vaccine, Avaxim may not achieve 100% protection in all vaccinated individuals.
• Use a separate sterile needle and syringe for each individual to prevent transmission of infectious agents.

There is limited data on overdose with Avaxim, as it is administered as a single measured dose by a healthcare professional. A dose higher than recommended, or an extra dose given in error, is not expected to cause serious harm but may increase the likelihood of injection-site or systemic reactions such as soreness, fever, or fatigue. If an overdose or vaccination error is suspected, or if the recipient develops any severe or unusual symptoms after receiving Avaxim, seek immediate medical attention or contact the nearest emergency department/poison control service.

Store Avaxim refrigerated between 2°C and 8°C (36°F to 46°F). Do not freeze - discard the vaccine if it has been frozen, as freezing destroys potency. Protect vials/syringes from light. Keep out of reach of children. Do not use after the expiry date printed on the pack.

Pediatric: Avaxim is approved for children from 12 months of age using the pediatric dose and schedule. Safety and efficacy in infants younger than 12 months have not been established, largely due to possible interference from residual maternal antibody.

Elderly: No dedicated dose adjustment is required in older adults; however, immune response may be somewhat reduced with advancing age, similar to other vaccines.

Renal/Hepatic impairment: No specific dose adjustment is established; patients with chronic liver disease are, in fact, a priority group for Avaxim given their higher risk of severe outcomes from HAV infection.

Immunocompromised persons: May have a diminished immune response to Avaxim (see Precautions and Warnings); vaccination is still generally recommended.

Avaxim is given as a 2-dose primary series, not an ongoing/chronic treatment. The second dose should be given 6-12 months after the first to complete the series. Once the full 2-dose series is completed, protection is expected to be long-lasting, likely lifelong, in immunocompetent individuals, and routine booster doses are not currently recommended.

Vaccines; viral vaccines; inactivated (killed) viral vaccines; monovalent hepatitis A vaccines.

Inactivated Hepatitis A vaccine works by exposing the immune system to formalin-inactivated hepatitis A virus antigen adsorbed on an aluminum adjuvant. Because the virus is fully inactivated, it cannot replicate or cause disease, but its viral proteins are still recognized by the immune system as foreign. This triggers antigen-presenting cells to activate B-lymphocytes (producing neutralizing anti-HAV IgG antibodies) and T-helper cells, generating durable immune memory. On subsequent natural exposure to hepatitis A virus, these pre-formed antibodies and memory cells rapidly neutralize the virus, preventing clinical infection.

Avaxim is indicated for children starting at 12 months of age, given as a 0.5 mL intramuscular dose in a 2-dose series 6-12 months apart. It is a routinely recommended part of childhood immunization schedules in many countries to protect against hepatitis A, which can otherwise cause outbreaks in daycare and school settings. Safety and efficacy of Avaxim in infants younger than 12 months have not been established. Common reactions in young children include irritability, drowsiness, loss of appetite, and injection-site redness, which are generally mild and self-limited.