Many good comments - a couple:
If they actually perform the study the result will be a paper of dubious ethics, which should be retracted. This is the Tuskegee Syphilis Study revisited. Retraction is not just about fraud, it is about any poor ethics.
If there had never been any safety or effectiveness studies of the Hep-B vaccine, that would make sense.
Once there have been safety and effectiveness studies, the calculus changes.
Let me use a non-politically-charged example. There is some correlational evidence that aspirin may help prevent a certain cancer in older men who have a pre-cancer condition. At some point in the past it could have been fully ethical to do a randomized controlled trial to see if this was actually true.
However, that study cannot ethically be done now, because it has been solidly established that low doses of aspirin have a heart-protective effect in men in that age class, and a large proportion of them are already taking it for that reason. So a trial would either have to exclude such men (which introduces a serious bias, because if you are *not* taking aspirin there is likely a reason -- such people are not a random sample) or forbid some of them from taking aspirin anymore, which would endanger their lives.
Trial ethics must be assessed based on the body of evidence we already have. Once we knew aspirin was saving lives in this group, we could not ethically withhold it.
If you wanted to show that the proposed trial was indeed ethical, it would take a meticulous examination of the existing trials for this vaccine and a detailed showing of why they are not sufficient. If they are sufficient, the trial is flatly unethical. This is not something we get to guess about. There are a whole lot of lives at stake, because the death rate from complications of Hep-B in Guinea-Bissau is very, very high.
I have not been able to find any such detailed showing. If it exists it needs to be out there for examination and discussion. If it doesn't exist, you cannot ethically do this trial given what's been established by previous ones, just like in my aspirin example.
One also has to ask, if the intent of the trial is to assess side effects (which is what I've gathered from discussions of it), why you would conduct it in a country where Hep-B is endemic and a very serious public health problem. That seems to maximize the potential harm. It might be ethical for me to enroll my hypothetical newborn in such a study, because the chance that they are exposed is extremely low, so the information on safety might justify the tiny additional risk. But the same is not true for a Guinean baby. If, as the body of current evidence says, the vaccine works, you are exposing them to an enormous risk of illness and eventual death by withholding or delaying it.
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