His last tweet did not go unnoticed. On October 6, on X, the controversial microbiologist Didier Raoult spoke about a possible link between vaccination against Covid and a notable increase in cases of cancer. No less was needed to trigger two types of reactions: those of the notorious anti-vaxxers who took this new “revelation” at face value. And that of the doctors engaged in the fight against medical disinformation who rushed to debunk the affair. But is the hypothesis so far-fetched?
What do the studies cited by Didier Raoult say?
“Two studies, an Italian one covering 300,000 cases and a South Korean one covering eight million cases, present epidemiological studies reporting an increase in cancers among vaccinated people (+37%) and more among vaccinated people in Korea”writes the former president of the University Hospital Institute (IHU) of Marseille. But what do these studies really say?
The first, Italian, was carried out between 2021 and 2023 on nearly 300,000 people in the Pescara region. She suggests that unvaccinated people die twice as often as vaccinated people (3.56% versus 1.93%). On the other hand, the researchers noted a slightly higher risk of hospitalization for cancer in the months following vaccination. An effect which disappears, or even reverses, after a year. The authors themselves specify that their results are contradictory and do not allow us to conclude that there is a causal link between vaccine and cancer.
The second study, this time carried out in South Korea on 8.5 million people, observed an increase in several types of cancers (thyroid, stomach, colon, lung, breast, prostate, and especially pancreas) in those vaccinated. But again, these are statistical associations, not proof of causality.
Like the Italian researchers, the South Korean authors call for caution: their results are preliminary and require further work to understand possible links. They do not say that the vaccine causes cancer. But they study the correlation links.
A more than controversial scientific approach
But is Didier Raoult so alarmist as people say he is on this one? His detractors accuse him of “affirming” with great fanfare a link between vaccine and pancreatic cancer. Consulted, an oncology researcher, who prefers to remain anonymous, does not agree.
“Is he really drawing conclusions in this tweet? I don’t believe it. At no time does he say so. What I’m already reading is that he “reports” an increase in cancers among vaccinated people in these studies. And “asks” that these studies be reproduced. Which is the very basis of a hypothesis and a scientific approach.”
Carrying out observational studies is also common and necessary to discover the links between our consumption, our medications… and disease. “This is also how we have shown the role of tobacco in neck and lung cancer. Therefore, the systematic rejection of this type of study is not justified. Even if that’s not enough of course.”
Anti-Raoult arguments which are not always relevant…
Also, to disavow the professor banned from practicing, the arguments on these studies are raining down: the confusion between correlation and causality, a reality which is not biologically possible or even a bias not taken into account: those who are vaccinated are also those who are tested most often. “So what?” replies the oncologist.
“There is no incompatibility on this “hypothesis” (the vaccine which could cause more cancer). We know very well today that cancer is multifactorial and that certain factors can accelerate and make tumors grow. It is not at all crazy to imagine that a vaccine, via an impact on the immune system, could induce immunosuppression or modulation which allows cancer to accelerate. It is in any case to be investigated, and to respond.”
Just like the argument that an injunction in the arm could not reach the breast, or the pancreas. “It is the basis of vaccination, I remind you, to seek to have an effect at a distance from where the product is injected. So the argument is absurd.”
“A signal to explore”
According to the expert, we should even go further. “It would also be good if this triggered other types of investigation complementary to observational studies, which are studies on animal models, cell cultures, etc. They are missing, I remind you, for many vaccines against COVID. This does not mean that we must reject the drug outright. But that we must try to understand it“.
Whether we like Professor Raoult’s theories or not, perhaps we should not ignore everything he says, out of principle. “I believe that we should not reject these data. We should not take them at face value either. On the other hand, they certainly constitute a signal to be explored, and that there is no reason to reject it a priori because it is not plausible. Or because it is Raoult who is talking about it” concludes our expert.