Update: A newly revised protocol of the CDC-funded Hepatitis B vaccine trial in Guinea-Bissau. "This is still bad."

A January 14 document fails to address major ethical issues identified in the version published here yesterday. "The University of Southern Denmark is complicit in this unethical research conduct."

Jan 16, 2026

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Yesterday, Inside Medicine published the protocol for the Hepatitis B birth dose trial being conducted by Danish researchers on babies in Guinea-Bissau. That document, dated September 17, 2025, was widely criticized by experts around the world, including the active CDC employee who leaked it, who called the study "another Tuskegee.”

Hours later, Melody Schreiber reported in The Guardian that the trial had been “canceled,” according to a senior official in the Africa CDC. While clearly a credible source, the Africa CDC is not directly involved in this trial. So, the status of this trial remains unclear. Shortly after The Guardian story was published, an HHS official reached out to Inside Medicine to say, on background, that the trial was “not canceled” and was “proceeding as planned.” A similar statement was published by Scientific American.

On Thursday evening, a former CDC employee shared a revised protocol of the controversial study, which is dated January 14. Unlike the September draft published here yesterday, this latest version indicates that the protocol received approval from the Guinea-Bissau Committee of Ethics on November 5, 2025. Asked to confirm its authenticity this evening, an HHS spokesperson declined to comment.

Here, for the first time in public, is the revised protocol. (The previous version can be found here.)

Hepatitis B vaccine trial protocol (Jan 2026)

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While its provenance is unclear, metadata indicates that the author of the document is Frederik Schaltz-Buchholzer, the principal investigator of the trial. I reached out to Professor Schaltz-Buchholzer, but have not received a response.

Verdict: “This is still bad.” Ethical concerns are not adequately addressed.

The source of the new protocol, a former CDC scientist, concluded that very little had materially changed from the September version. A current CDC official—the one who provided the previous version—agreed. While he had not seen the January 14 version until I shared it with him this evening, that official promptly read it and provided the following reaction:

“There are some very minor changes to the study protocol, but none of the ethical or legal concerns that have been identified with the original protocol have been adequately addressed by the revised protocol. The revised protocol continues to assert that the study is ethically acceptable to conduct in Guinea-Bissau because it is not yet the universal standard of care in Guinea-Bissau to provide the birth dose.
The revised study would still not pass muster with a US Institutional Review Board (IRB) for [ethical] approval, so it remains illegal for HHS to have funded this study, and it is grossly unethical for the investigators to be conducting this study by exploiting Guinea-Bissau’s poverty and current inability to provide the birth dose universally.”

He also noted that the new version includes a reference (perhaps a justification) for the new trial by invoking recent changes made by the CDC’s Advisory Committee on Immunization Practices, whose voting members were recently entirely replaced by Secretary Robert F. Kennedy Jr.

“The investigators also added a reference to the outcome of the December ACIP meeting, where the US recommendation for the birth dose was weakened in what you are well aware was an extremely controversial move. What I really don’t understand is why the University of Southern Denmark hasn’t shut this down. This would never pass muster with a European IRB, either.”

As above, the new protocol indicates that, somehow, the Guinea-Bissau Committee of Ethics (its IRB) approved this plan in November. However, the document does not indicate whether the IRB of the trial’s sponsor, the University of Southern Denmark, has approved this study. Sources continue to maintain that no IRB approval has been granted by the US CDC, which is funding the trial using $1.6 million in taxpayer money.

The details: Expert analysis from a clinical trial designer.

Dr. David Boulware, a clinical trial designer and professor at the University of Minnesota also reviewed the revised protocol this evening for Inside Medicine. (His analysis of the previous version can be found here.) Here’s what he wrote, with my own added context and commentary in bracketed italics:

Core unresolved issue: foreseeable harm to infants of unknown HBsAg-positive [Hepatitis B-infected] mothers. Relying on “known carrier” status [that is, whether the mother knows she is a carrier, which most in Guinea-Bissau do not, as the Danish researchers freely admit] is inadequate in a context where screening is not routine. The investigators could ethically eliminate this problem by testing all mothers for Hepatitis B antigen and excluding those who are Hepatitis B antigen-positive. Such additional testing might cost 1-2% of the total $1.6 million budget, yet the investigators are unwilling to do so, or are ignorant on fundamental medical ethics. It remains unethical to knowingly include children at high risk for vertical transmission of Hepatitis B while withholding a known effective intervention to prevent chronic infection.
A limited serosurvey [blood testing for signs of infection] of 250 mothers and children are not a substitute for assessing the comprehensive risk and transmission of Hepatitis B to infants. The University of Southern Denmark is complicit in this unethical research conduct.
There is a lack of IRB approval by the home institution [The University of Southern Denmark] or by an IRB of the HHS or CDC. This deviates from standard US policy, which requires the home institution to approve the research (and/or CDC/HHS). [Note: When the CDC funds a study of human subjects taking place outside the US, approval by a US-based IRB is almost always required.]
False claims of benefit. On pages 19-20, it states that “Given that RCTs [randomized controlled trials] indicate beneficial, non-specific effects of both BCG and OPV [tuberculosis and polio vaccines, respectively], all participants are thus expected to benefit from their participation in the trial.” This is untrue, as these vaccines are provided as standard of care outside of the trial.
The investigators remain ethically challenged. On page 20, it says, “While the protective specific effect of HBV0 [Hepatitis B vaccine] is well-established, the broader effects of HBV0 have never been investigated. With established certainty regarding the beneficial specific effects of HBV0 in regard to vertical transmission of hepatitis B, absence of tangible benefit for babies born to HBsAg-negative mothers, no trials comparing BCG+OPV vs BCG+OPV+HBV0 and uncertainty regarding the short-term and long-term broader health effects of HBV0, there is equipoise for an RCT.” This statement demonstrates the moral duplicity of the investigators as: 1) The investigators recognize the benefit of Hepatitis B [birth dose] vaccines in preventing vertical transmission; 2) It ignores the expected 19% of mothers who are positive for Hepatitis B; 3) It falsely states that there is equipoise [i.e., equipoise is when a study is ethical to conduct because there is genuine debate among experts about whether the treatment being studied is effective]; 4) They do not even attempt to measure the foreseeable harms of Hepatitis B transmission [including the 70-90% likelihood of infection from mother to newborn leading to chronic liver disease including cirrhosis, cancer, and eventually death.]

Boulware believes that there is one potential way the trial might be ethical. “If the trial only enrolled children born to [verifiably] Hepatitis B-negative mothers, there could be legitimate claims of equipoise.” However, that doesn’t mean such a trial would be a useful exercise. “It might be a dumb trial,” he added, “but at least it would not be overtly unethical.”

He reiterated his condemnation of the University of Southern Denmark. “That the investigators are fundamentally unable to recognize this basic ethical problem and an easy solution is problematic.” He said that under normal US governmental ethics that such conduct would trigger a re-evaluation of the university’s good standing as a CDC research partner.

While I agree, I would also add that since the primary outcome of the revised study remains completely meaningless, the study will only be able to detect potential harms due to vaccination—which the researchers might be able to game because they haven’t specified precisely how they will measure any neurocognitive outcomes—but not any benefits. That, finally, seems to be the point.

Other changes.

A series of other changes appear in the January 14 protocol, our source of the new protocol pointed out. Highlights include:

Funding has been awarded by the Pershing Square Foundation and the Bluebell Foundation, in addition to the US CDC. It is unknown how much funding has been added to the $1.6 million committed by the US CDC.
Some of the secondary outcomes have been modified, including longer follow-up for mortality, albeit not nearly long enough to capture the effects of Hepatitis B acquired early in life.

What now?

It’s possible that the outcry around the September protocol has already led the US to pressure the Danish researchers to clean this mess up. But that is speculation, on my part. Moreover, the latest version will do little to assuage the study’s loudest critics—from experts, to ethicists, to current and former CDC officials—who seem to have collectively gained the attention of HHS officials at the helm of this process.

Indeed, the goal of the experts I’ve spoken to remains the same: pressure Secretary Kennedy and HHS to terminate this trial and use the money to begin providing the birth dose of the Hepatitis B vaccine to newborns in Guinea-Bissau months before their universal program is scheduled to begin. That would be a win.