Hepavax-B

• Prevention of Hepatitis B Virus (HBV) infection
• All age groups including neonates, children, adolescents, and adults at risk.
• Indicated for individuals at high risk, including healthcare workers, dialysis patients, travelers to endemic areas, and those with chronic liver disease.
• Post-exposure prophylaxis
• In combination with Hepatitis B immune globulin (HBIG) for neonates born to HBsAg-positive mothers or after exposure to blood or body fluids from an infected individual.
• Off-label / special populations
• Can be used in immunocompromised patients with adjusted dosing schedules.
• Administered in catch-up immunization programs for unvaccinated older children and adults.

Administered intramuscularly (IM), preferably in the deltoid muscle for adults or anterolateral thigh for infants.

• Standard schedule (infants)
• 0, 1, and 6 months: 0.5 mL per dose
• Birth dose: within 24 hours of birth for neonates at risk
• Adult schedule
• 0, 1, and 6 months: 1 mL per dose
• Alternative accelerated schedule: 0, 1, 2 months with booster at 12 months
• Post-exposure prophylaxis
• Neonates born to HBsAg-positive mothers: Vaccine at birth plus HBIG; complete standard series as above.
• Adults after exposure: Start vaccine series immediately, optionally with HBIG depending on exposure type.
• Special populations
• Immunocompromised individuals may require double doses or additional boosters.
• No adjustment necessary for renal or hepatic impairment.

Hepatitis B vaccine [rDNA] is a recombinant DNA vaccine containing hepatitis B surface antigen (HBsAg) produced in yeast cells. Upon intramuscular administration, HBsAg is recognized by antigen-presenting cells (APCs), activating both humoral and cellular immune responses. This stimulates B lymphocytes to produce anti-HBs antibodies and memory T cells, providing protective immunity. The vaccine does not contain live virus and cannot cause infection; protective antibody titers usually develop within 1–2 months after completing the series.

• Absorption: Rapidly taken up by APCs at the injection site; systemic distribution is minimal.
• Distribution: Local immune response in lymph nodes; minimal systemic circulation of antigen.
• Metabolism: Antigen processed by immune cells; no hepatic metabolism.
• Excretion: Antigen components degraded by cellular proteolytic mechanisms; not renally excreted in active form.
• Onset & duration: Protective antibody titers usually appear 1 month after the second dose, with long-term protection lasting at least 20 years after complete vaccination.

• Pregnancy: Category C; indicated for women at risk of HBV exposure. No evidence of fetal harm with recombinant vaccine.
• Lactation: Safe for breastfeeding; vaccine antigens are not transferred in significant amounts to milk.

• Primary therapeutic class: Vaccine / Immunoprophylactic agent.
• Subclass: Recombinant subunit vaccine.

• Known hypersensitivity to yeast or any vaccine component.
• Previous severe allergic reaction to a prior dose of Hepatitis B vaccine.
• Acute moderate or severe febrile illness (temporary deferral).

• Anaphylaxis risk: Rare; observe for 15–30 minutes post-injection.
• Immunocompromised patients: May have reduced response; monitor antibody titers.
• Latex allergy: Check vial stopper if latex-sensitive.
• Thrombocytopenia / bleeding disorders: Use caution with IM injection; apply pressure to prevent hematoma.
• Concurrent vaccines: Can be administered with other inactivated or live vaccines at separate sites.

• Common
• Injection site pain, redness, swelling
• Mild fever, fatigue, headache
• Uncommon
• Nausea, dizziness, arthralgia, myalgia
• Rare / serious
• Severe allergic reactions including anaphylaxis
• Neurological events (rare and usually transient)

• No significant CYP450 or metabolic enzyme interactions.
• Can be administered concurrently with other vaccines; use separate injection sites.
• Immunosuppressive therapy may reduce antibody response.

• WHO recommends universal birth dose within 24 hours for all newborns.
• CDC/ACIP recommends catch-up vaccination for unvaccinated adolescents and adults.
• For post-exposure prophylaxis, combination of vaccine + HBIG is standard for high-risk exposure.
• Emphasis on using recombinant DNA vaccines for enhanced safety over plasma-derived products.

• Temperature: Store 2°C–8°C (refrigerated); do not freeze.
• Light & humidity: Keep in original protected vial; avoid light exposure.
• Handling precautions: Inspect for particulate matter; discard if compromised.
• Reconstitution: Some formulations are pre-filled; if lyophilized, reconstitute with sterile water immediately before use.