World's 1st COVID human challenge trial suggests spread of virus not correlated to symptoms
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The world's first "human challenge" study in volunteers who were exposed to the novel coronavirus suggested that having symptoms did not have an effect on how likely an infected person may communicate the disease on to other people.
The study was conducted by Open Orphan's (OTCPK:OPORF) unit hVIVO, in partnership with Imperial College London, the Vaccine Taskforce and Department of Health and Social Care (DHSC), and the Royal Free London NHS Foundation Trust.
The study results were published in the journal Nature Medicine.
In the trial, 36 volunteers aged 18â29 years without evidence of previous infection or vaccination were inoculated with the virus intranasally.
Eighteen people became infected, with viral load (VL) rising steeply and peaking at ~5 days after inoculation.
Virus was first detected in the throat but rose to significantly higher levels in the nose.
Two people remained asymptomatic. Mild-to-moderate symptoms were reported by 16 people, beginning 2â4 days after being exposed to the virus.
The study noted that, 'No quantitative correlation was noted between VL and symptoms, with high VLs present even in asymptomatic infection.'
The studyâs main goal was to identify an inoculum dose that induced well-tolerated infection in more than 50% of people, with secondary objectives to assess virus and symptom kinetics during infection.
All the main and secondary goals were met, according to the study results.
Andrew Catchpole, co-investigator on the study and chief scientific officer of hVIVO, said, "The SARS-CoV-2 characterization study has provided invaluable insights into the progression of COVID-19 infection in healthy young adults."
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