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What was claimed

The Recombivax HB hepatitis B vaccine was licensed based only on 434 doses given to 147 infants/children monitored for just 5 days per dose with no placebo or long-term follow-up

Our verdict

Needs caution

The package insert says the pediatric studies had 5-day monitoring, but other sources note longer follow-up in some studies and long-term follow-up data in broader vaccine programs. So it is inaccurate to say there was no long-term follow-up at all. The package insert confirms 434 doses in 147 healthy infants and children in three clinical studies. But other sources indicate the original pivotal program included about 1,600 participants across age groups, so “only” is an overstatement. (Only 1 of 3 AI systems responded.)

1 AI system responded32 sources citedChecked Sep 22, 2026

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Key findings

There was no long-term follow-up.

Incorrect84%
1 AI checked

Recombivax HB was licensed based only on 434 doses given to 147 infants/children.

Misleading90%
1 AI checked

There was no placebo.

Verified86%
1 AI checked

Those infants/children were monitored for just 5 days per dose.

Verified98%
1 AI checked

Verified against 32 sources

vaccinedatanavigator.orgfda.govchop.edumerck.canvic.orgdownloads.regulations.govicandecide.orgpmc.ncbi.nlm.nih.govmerckvaccines.compdf.hres.caicandecide.orgcorvelva.orgmerckvaccines.comfda.govhepatitisb.uw.edupubmed.ncbi.nlm.nih.govdailymed.nlm.nih.govsciencedaily.comcdc.govsciencedaily.comcdc.govscience.thewire.indailykos.compharmaphorum.comcdc.govyahoo.comcancerletter.compharmaphorum.comapnews.comfinance.biggo.compharmaphorum.comtehrantimes.com

Detailed Analysis

The quoted numbers are substantially supported by the Recombivax HB package insert, but the claim is incomplete and potentially misleading. The insert confirms 434 doses in 147 infants/children monitored for 5 days after each dose, yet other sources note broader pre-licensure studies and longer follow-up in some groups, so “licensed based only on” is too strong.[2] [3]

Why this verdict

  • The quoted numbers are substantially supported by the Recombivax HB package insert, but the claim is incomplete and potentially misleading.
  • The insert confirms 434 doses in 147 infants/children monitored for 5 days after each dose, yet other sources note broader pre-licensure studies and longer follow-up in some groups, so “licensed based only on” is too strong.[2] [3]

Claims checked

There was no long-term follow-up.

Incorrect84%
The package insert says the pediatric studies had 5-day monitoring, but other sources note longer follow-up in some studies and long-term follow-up data in broader vaccine programs.[3] [12] So it is inaccurate to say there was no long-term follow-up at all.

This claim may mislead readers without added context.

Recombivax HB was licensed based only on 434 doses given to 147 infants/children.

Misleading90%
The package insert confirms 434 doses in 147 healthy infants and children in three clinical studies.[2] But other sources indicate the original pivotal program included about 1,600 participants across age groups, so “only” is an overstatement.[1] [3]

This claim may mislead readers without added context.

There was no placebo.

Verified86%
The vaccine-data summary lists the Recombivax HB pediatric studies as having no control/comparator and no placebo.[1] The package insert excerpt does not describe a placebo arm for those three infant/child studies.[2]

What other AI think

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