10/27/2025
The Recombivax HB vaccine is given to babies within hours of birth. Yet very few have actually read the manufacturer’s insert. Let’s look at what it really says; not opinions, not headlines, but their own words. 🧾👇
VACCINE INSERT REVIEW: RECOMBIVAX HB
Disclaimer
Nothing here is medical advice. It’s information — drawn directly from the manufacturer’s own documentation. You’re responsible for your health, and you deserve the full truth before making any medical decision.
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1. Vaccine Overview
Name: Recombivax HB (Hepatitis B Vaccine, Recombinant)
Manufacturer: Merck & Co.
Initial U.S. Approval: 1986
Indicated For: Prevention of infection caused by all known subtypes of hepatitis B virus
Approved For: Individuals of all ages (including newborns)
Schedule:
• Birth through 19 years: 0, 1, and 6 months
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2. Study Design Summary
Clinical trials used for approval involved 147 infants and children (up to 10 years old) and 1,252 healthy adults who were monitored for 5 days after each dose.
In children: 434 doses were given and observed for 5 days post-injection.
In adults: 3,258 doses were given and observed for 5 days post-injection.
Monitoring relied on parent or subject symptom checklists.
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3. Placebo or Control Group
None.
All trials compared Recombivax HB to another hepatitis B recombinant vaccine or to different dosing regimens of the same vaccine.
There was no saline or inert placebo group, and all participants received formulations containing aluminum adjuvants.
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4. Reported Adverse Reactions (During Study)
Within 5 days of vaccination:
• Children: Injection site reactions (0.2%), systemic reactions (10.4%)
• Most common: Irritability, fever (≥101°F), diarrhea, fatigue, diminished appetite, rhinitis
• Adults: Injection site soreness (17%), fatigue/weakness, headache, fever, malaise, nausea, diarrhea
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5. Post-Marketing Adverse Events
The insert lists serious neurological, autoimmune, and hypersensitivity conditions reported after release, including:
• Neurological: Guillain-Barré syndrome, multiple sclerosis, transverse myelitis, seizures, Bell’s palsy, encephalitis
• Autoimmune: Lupus, vasculitis, arthritis, polyarteritis nodosa
• Allergic/Immune: Anaphylaxis, serum sickness-like reactions, urticaria, erythema multiforme, Stevens-Johnson syndrome
• Other: Alopecia, eczema, optic neuritis, tachycardia, tinnitus, thrombocytopenia, muscle weakness
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6. Ingredients and Additives
Each dose contains:
• Antigen: Hepatitis B surface antigen (HBsAg) produced in genetically engineered Saccharomyces cerevisiae yeast
• Adjuvant: ~0.5 mg aluminum (amorphous aluminum hydroxyphosphate sulfate)
• Preservative/Residuals: