Hepatitis B vaccine adverse events and autoimmune concerns — a primary-source review of VAERS data, post-market safety signals, and published surveillance studies.
Post-licensure surveillance and FOIA-derived findings on the hepatitis B vaccines on the US childhood schedule. The most significant downstream evidence comes from the Heplisav-B trial (2017) — an adult Hep B vaccine that used Engerix-B as its control and revealed a 5.3% serious adverse event rate in the Engerix-B comparator group, deemed "acceptable" because the new vaccine had a similar 6.2% rate. ICAN FOIA litigation revealed zero documented cases of hepatitis B transmission in a US school setting despite hepatitis B being a school-entry mandate in most states.
In 2017, the FDA licensed Heplisav-B, a new adult Hep B vaccine. Heplisav-B's licensure trial used Engerix-B as the active control. The trial revealed:
| Vaccine | Serious Adverse Event Rate |
|---|---|
| Heplisav-B | 6.2% |
| Engerix-B | 5.3% |
Both rates were deemed acceptable by the FDA because the rates were similar between groups. The FDA did not investigate why the Engerix-B comparator group had a 5.3% SAE rate.
A 5.3% and 6.2% serious adverse event rate in the control and test groups respectively — both alarmingly high — raised no regulatory red flags because the two rates were similar to each other.
The FDA SAE definition includes: death, life-threatening events, hospitalization, disability or permanent damage, congenital anomalies, required intervention to prevent permanent impairment, and other serious medical events.
This finding is significant because it provides post-licensure evidence (from a follow-on product's trial) of the SAE rate associated with the original Engerix-B vaccine — data that was never collected in Engerix-B's own 4-day-monitoring trial.
The CDC schedule mandates hepatitis B vaccination at birth, with the rationale that the vaccine prevents hepatitis B transmission among children. State-level mandates require Hep B vaccination for school entry.
ICAN filed a FOIA request with the CDC asking for documentation of hepatitis B transmission in school settings. The CDC produced zero documented cases — no records of any child contracting hepatitis B from another child in a school setting.
This undermines the primary stated rationale for school-entry Hep B mandates: if there are no documented school-setting transmission cases, there is no school-setting transmission to prevent. Hepatitis B is transmitted through blood, sexual contact, and needle sharing — not through routine childhood interaction.
ICAN sued the FDA over Engerix-B's pre-licensure safety documentation. The litigation lasted years. The result:
The 4-day monitoring window was the totality of the safety data available to the FDA at licensure — and remained the totality after years of litigation seeking additional data.
Hepatitis B vaccines are nominally subject to post-licensure surveillance through:
These surveillance systems have not generated regulatory action specific to the hepatitis B vaccines despite the underlying limitations of each system. See the linked concept pages for documentation of why these systems have not produced reliable post-licensure safety signals.
In court stipulation responding to ICAN's lawsuit, the CDC identified its complete evidence base for claiming infant vaccines do not cause autism: 20 studies. Upon review, zero of those 20 studies examined hepatitis B vaccine in the relevant infant age window for autism causation. See Post-Licensure Safety Monitoring.
Aaron Siri argues that hepatitis B vaccines are associated with more deaths attributable to vaccine adverse events than the disease itself causes in comparable US populations. This claim is based on CDC mortality data, VAERS reports, and post-licensure surveillance compilation.
Hepatitis B Vaccines (Pre-Licensure), Post-Licensure Safety Monitoring, VAERS, VSD (Vaccine Safety Datalink)
Frequently Asked Questions