Should we give people diseases to develop cures? | science and nature books


In the 1770s, an English doctor named Edward Jenner noticed that milkmaids did not seem to catch smallpox, the terrifying disease that killed about a third of people who caught it. He thought their frequent exposure to cowpox, a similar but less severe virus, might be what protected them. In order to test his hypothesis, he administered cowpox to his gardener’s eight-year-old son, then deliberately infected him with smallpox to see if he had become immune. He had, and Jenner successfully repeated the experiment. “Vaccination,” from the Latin word for cow, quickly became commonplace.

It was of course highly irresponsible to expose a child to a fatal disease without knowing for sure that he would survive. Even so, looking back, we can see that the benefits were immense: the vaccine was safe and highly effective. Demonstrating this fact and making it public encouraged countless others to follow his example.

This is an example – albeit an unusual one – of a “challenge trial”. It is a form of research where, rather than relying on data from natural infections, we deliberately expose someone to a disease in order to test the effectiveness of a vaccine or a treatment. Things have changed a lot since the days of Jenner, of course, when it was not uncommon for doctors to deliberately infect people with pathogens to try to find out what illnesses they caused. Even so, there’s a lingering sense that there’s something unethical about making someone sick on purpose. It’s no surprise – even in relatively recent history, deeply sinister medical experiments have been conducted that superficially resemble this kind of work. During World War II, for example, Imperial Japan set up a network of secret facilities to experiment on prisoners: while some were injected with plague and tetanus toxin, others were amputated. of their limbs – both as a form of torture and as a means of training. army surgeons for the battlefield. The grotesque crimes committed by the Nazis under the guise of scientific research are well known.

But this poisonous history should not blind us to the extraordinary power of provocation trials under strict conditions based on informed consent and designed to be as safe as possible. They could become increasingly important weapons in the arsenal of medical research, at a time when vaccine technology advances and the threat of diseases jumping from animals to humans increases.

Much has been done to mitigate risk: Challenge trials designed to advance malaria research have proven very sure, as the disease is now well understood and can be treated easily under close supervision. For tuberculosis, the trials used the mild BCG vaccine as a challenge test, instead of the bacteria itself. For respiratory syncytial virus (RSV), researchers recruited adults at low risk of severe disease. These experiments have already narrowed down a wide range of vaccine candidates and helped refine their ingredients. With their help, the world will soon have two effective vaccines against malaria, which kills hundreds of thousands of people every year, as well as the first vaccines against RSV, which kills tens of thousands of infants every year.

But not all illnesses are like these. We don’t always know the dangers that volunteers may face; we don’t always have treatments ready. Then what ? How can we consent to risks that remain difficult to quantify? How should they be compensated for taking these risks?

OE COULD, of course, avoid these questions altogether and rely on other types of research. But that doesn’t always work: sometimes, animal testing is tricky and uninformative, because the disease does not develop in the same way as in humans. For human trialssuch as those studying the effectiveness of a vaccine against Zikait may take tens of thousands of people and several years conduct a single study because only a fraction of participants in the placebo group will ever develop the disease, making it difficult to see what difference the drug or vaccine would make.

In contrast, challenge trials can be very informative in a matter of weeks, with far fewer volunteers. And the stakes can be incredibly high. It is easy for us to grasp the risks that volunteers might face after being injected with a pathogen, but more difficult to keep in mind the number of people who suffer from diseases each day and the number of lives. that would be saved if a treatment or a vaccine were developed and launched. get out earlier. Take the Covid-19 pandemic. At the end of last year, when the death toll was estimated to have reached around 17.8 millionit is also estimated that 20 millions had been saved by vaccines. In the years to come, they will hopefully save millions more. The burden of suffering relieved by vaccines is immense – and the sooner they arrive, the better.

Researchers around the world were able to rapidly develop Covid vaccines through a combination of luck and initiative: Similar vaccines were already in development; the disease was so widespread that it was easy to recruit people for studies; and the research was massively well funded and high priority because it was a global emergency. If this had not been the case, we would have been in dire straits – just like doctors hundreds of years ago, we would have faced an imminent threat that we did not understand and could not combat.

In order to ensure that we are as protected as possible against current and future threats, we should try to eliminate the stigma that still haunts provocation trials, by making them more familiar in our toolbox. And if we thought about the act of volunteering isn’t getting infected a rather peculiar and reckless thing to do? What if we think of volunteers more like first responders rushing to help in a disaster? What if we recognize the sacrifices they have made on our behalf by holding them in particularly high esteem, such as firefighters or paramedics, by rewarding them not just with money, but with recognition, support for long term and respect?

Perhaps the greatest reward of all would be to make sure their efforts are worthwhile: by designing open and transparent trials, applying them when and where they could make a real difference, and developing the tools to learn as much as possible. In short, by helping them save thousands, if not millions, of lives.

Saloni Dattani is a research fellow at King’s College London and founding editor of Works in Progress.

Further reading

War on Smallpox: Edward Jenner and the Global Spread of Vaccination by Michael Bennett (Cambridge, £29.99)

Vaxxers: A Pioneering Moment in Scientific History by Sarah Gilbert and Catherine Green (Hodder & Stoughton, £20)

The Mosquito: A Human History of Our Deadliest Predator by Timothy Winegard (Text, £12.99)


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