The revelations of the first and controversial trial that deliberately infected covid patients

The world’s first Covid “human challenge” trial, which deliberately infected healthy people, offers a unique insight into the early stages of the disease.

Thirty-six young, healthy, unvaccinated volunteers at the Royal Free Hospital in London were infected with the virus.

The results show where and when the virus establishes itself in the body, and indicate that some people resist infection.

Future human challenge trials could help find the next generation of vaccines and medicines against covid.

And they allow scientists to study the early stages of an infection, even before symptoms develop.

first symptoms

Each of the volunteers, ages 18 to 30, received an identical dose of covid through the nose, equivalent to the amount of a single drop expelled from a person’s nose during the peak of their covid infection.

But only half of them became infected.

Understanding how others, unvaccinated and without immunity from previous infections, resisted the virus will be the focus of future research.

In those who developed an infection, the virus took effect quickly, with the first symptoms and positive test results appearing in just 42 hours.

The previous consensus had been that it took five days from exposure to the virus to the first symptoms.

And although the virus establishes itself in the throat, the greatest number was found when it traveled to the nose, leading the researchers to emphasize the importance of masks that cover both.

“Greater Impact”

“It’s a really unique study,” says Professor Christopher Chiu, from the Institute of Infections at Imperial College London.

The amount of virus peaked about five days after infection and remained detectable up to 12 days later.

Symptoms were mild, but some volunteers suffered a prolonged loss of the sense of smell.

“Lateral flow tests correlate very well with the presence of infectious virus,” says Professor Chiu.

“Although on the first day or two they may be less sensitive, if you use them correctly and repeatedly, and act on the results if you test positive, this will have a big impact on stopping viral spread.”

“key data”

“Greater Impact”

“It’s a really unique study,” says Professor Christopher Chiu, from the Institute of Infections at Imperial College London.

The amount of virus peaked about five days after infection and remained detectable up to 12 days later.

Symptoms were mild, but some volunteers suffered a prolonged loss of the sense of smell.

“Lateral flow tests correlate very well with the presence of infectious virus,” says Professor Chiu.

“Although on the first day or two they may be less sensitive, if you use them correctly and repeatedly, and act on the results if you test positive, this will have a big impact on stopping viral spread.”

“key data”

The virus used was one of the first variants taken from a patient at the start of the pandemic.

Other studies they will explore newer versions.

The main finding – that it is safe to carry out human challenge tests – opens up new avenues of research.

Human challenge trials have produced advances in medicine, such as the new typhoid vaccine, and it is hoped that the same approach could lead to a new generation of vaccines and antivirals against covid.

The findings were published online but have not been formally reviewed by other scientists.

Deputy Chief Medical Officer for England, Professor Jonathan Van-Tam, said: “This important study provides more key data about Covid-19 and how it spreads, which is invaluable in learning more about this new virus, so we can adjust Our answer”.