I stumbled upon The River almost by accident. A battered copy sat quietly on a secondhand bookstore shelf. I had never heard of it. Published in 1999, Edward Hooper’s nearly 1,000-page investigation into the origins of HIV/AIDS proposes that the pandemic may have begun not through a “natural spillover” of the virus from primates to humans, but through the use of an experimental oral polio vaccine in the Belgian Congo during the late 1950s. The vaccine, he argues, may have been grown in chimpanzee tissue infected with SIV, the simian precursor of HIV.
Known as the OPV (oral polio vaccine) hypothesis, this idea was fiercely resisted by the scientific community. What struck me, reading through the massive and meticulously sourced text, was not just that the hypothesis had been dismissed — science, after all, thrives on falsification — but how it was dismissed, and what questions were left unexamined.
Naturally, I wanted to know more. Had the theory been refuted? What happened to the original vaccine samples? Why have many of the scientists quoted in the book later distanced themselves from it, or minimized their recollections? And why, even after all these years, has The River never received wider distribution in the non-Anglophone world?
The deeper I looked, the more unsettling the story became.
In 2000, shortly after the book’s publication, the renowned evolutionary biologist W.D. Hamilton — who did not endorse Hooper’s hypothesis, but believed it deserved thorough investigation — traveled to the Congo to collect chimpanzee samples. He died of cerebral malaria shortly after returning to the UK. That same year, a public symposium at the Royal Society concluded that the OPV hypothesis was unsupported: no evidence of chimpanzee DNA or SIV was found in the vaccine samples, and phylogenetic analyses placed the emergence of HIV-1 decades earlier than the Congo trials.
Case closed. Or so it seemed.
Yet if one digs a little deeper, doubts remain — not necessarily about the hypothesis itself, which most genetic and molecular data now contradict, but about how the scientific establishment handled the debate. Why did it take so long to test the original vaccine batches? Why were so many questions met not with inquiry but with silence? Why did so many of the key figures interviewed by Hooper later retreat from their earlier statements?
Reading The River, one does not feel seduced by a conspiracy theory — although there are elements here that would tempt such an interpretation — but rather confronted with a legitimate question that was institutionally smothered. The OPV hypothesis may not hold up to current genetic evidence: HIV-1 likely emerged earlier, between 1910 and 1930, perhaps through the hunting or butchering of primates. But Hooper’s underlying critique remains: science, like any human institution, protects reputations, conceals mistakes, and sometimes discourages uncomfortable questions — especially when those questions threaten its moral authority.
One particularly disturbing detail: The River has never been translated into Spanish. Not a single edition. This despite its nomination for the Pulitzer Prize, despite its historical and epidemiological value, and despite the global importance of the AIDS crisis. Is it simply a case of editorial neglect? Or is it a symptom of something deeper — a discomfort with books that interrogate science too closely, or demand too much accountability?
As a teacher, I have spoken in class about pandemics, about scientific fallibility, about critical thinking. Like all of us, I lived through the COVID-19 pandemic, through its whirlwind of contradictory data, vanishing reports, shifting narratives. And so I cannot read The River today as just a theory about the origins of AIDS. It is a cautionary tale about what happens when science, under pressure to maintain its institutional credibility, begins to behave like power.
We now know that HIV-1 most likely crossed into humans between 1910 and 1930 in Central Africa, unrelated to the polio vaccine. Genetic studies of SIV strains in wild primates corroborate this. But those findings do not erase Hooper’s central warning: What other medical truths are being obscured, dismissed, or left unexplored—not because they are wrong, but because they are inconvenient?
Reading The River is not just an immersion into one of the great epidemiological mysteries of the twentieth century. It is also a sobering meditation on how knowledge behaves when confronted by its own fragility. The book is not perfect. It is sprawling, messy, and sometimes obsessive. But it is also brave. And its questions remain.
Not every scientific error is fatal. But refusing to examine the possibility of error—that may be the real danger.
