A 3D printed coronavirus model is seen in front of the words Coronavirus disease (Covid-19) on display in this March 25, 2020 illustration. REUTERS/Dado Ruvic/Illustration/File Photo
April 1 – The world’s first ‘human challenge’ study, in which volunteers were intentionally exposed to the coronavirus, has found that symptoms had no effect on how likely an infected person was to pass the disease on to others.
The findings underscore the difficulty of preventing community infections as the World Health Organization (WHO) warns of a surge in cases.
The research project, conducted by Open Orphan (ORPH.L) with Imperial College, London, showed that among the 18 participants who contracted COVID-19, the severity of symptoms or whether they developed symptoms at all had nothing to do with it viral load in their airways. Continue reading
Viral load, or the tendency to shed the virus, was measured using two methods known as focus forming assay (FFA) and quantitative polymerase chain reaction (qPCR).
“There was no correlation between the amount of viral shedding by qPCR or FFA and the symptom score,” the researchers said in an article published by the scientific journal Nature Medicine.
The Imperial trial exposed 36 healthy young adults with no history of infection or vaccination to the original SARS-CoV-2 strain of the virus and monitored them in a quarantine environment. Continue reading
Since antibodies against the virus were found in two subjects, they were excluded from the analysis. Just over half of them have contracted the virus.
There were no serious adverse events, and the human challenge study model was shown to be safe and well-tolerated in healthy young adults, the research team said earlier this year.
Reporting by Ludwig Burger; Edited by Robert Birsel