Back on August 30th, 2021
, I shared how the UK was beginning a human challenge trial, deliberately infecting unvaccinated volunteers with SARS-CoV-2. The aim was to not rely on incidental infection to study the disease, and understand more directly the progression of the virus, all while under intensive study & care.
The initial results were published a few weeks ago. Some caveats:
- To reduce risks, the population was exclusively comprised of people between ages 18-30.
- The volunteers were infected with the original, ancestral strain of SARS-CoV-2. AKA, this wasn’t Alpha, Delta, or Omicron.
Here are some highlights:
Of the 36 total participants,
half (18) of the participants developed a SARS-CoV-2 infection. Two of these participants were asymptomatic. The remaining 16 developed mild symptoms, including a runny nose, sneezing, and sore throat.
The average time between exposure to the virus and the development of first COVID-19 symptoms is much shorter than previously thought:
On average, participants who got COVID-19 tested positive for the active virus after only 42 hours. This is contrary to the previous belief that people develop symptoms 5–6 days after exposure.
Viral load peaked at 5 days after exposure, but active virus was still detectable in some people after 12 days.
Lateral flow tests (aka rapid/antigen tests),
were a good indicator of whether a person has viable virus, even in those without symptoms of COVID-19.
Though the researchers recommended swabbing the throat as well as the nose for more reliable results.
You can read more details in the article below.