Open Orphan reports on world's first Covid-19 characterisation study

The AIM-traded firm said the results from the landmark study showed that a SARS-CoV-2 human challenge was safe in healthy young adults, and provided detailed insights into the course of Covid-19 infection, with potential positive public health implications.

As part of the study, researchers aimed to identify a dose of Covid-19 that caused a “safe and reliable” infection in unvaccinated volunteers with no prior SARS-CoV-2 infection.

The results detailed the outcome of the 36 healthy male and female volunteers aged 18 to 29, which were infected with the original SARS-CoV-2 strain challenge virus.

Open Orphan said hVIVO clinicians closely monitored volunteers in a controlled quarantined setting, and collected disease progression data to provide insights into Covid-19 infection.

Volunteers would be followed up for 12 months after discharge from the quarantine facility.

It said the key clinical insights included that 18 volunteers became infected with viral loads rising steeply, and peaking at around five days post-inoculation.

No quantitative correlation was noted between viral load and symptoms.

Open Orphan said there were no serious symptoms, with mild-to-moderate cold-like symptoms were reported by 16, or 88%, of 18 infected volunteers, including a stuffy or runny nose, sneezing, and a sore throat.

Some also experienced headaches, muscle and joint aches, tiredness and fever.

Anosmia - a lost or changed sense of smell - occurred in 13, or 72%, of infected volunteers.

Open Orphan said the average time from first exposure to viral detection and early symptoms, or the ‘incubation period’, was 42 hours, with the virus detected earliest in the throat, but at “significantly greater levels in the nose.

The virus was detected in the throat on average after 40 hours, and in the nose on average after 58 hours.

High levels of viable, or infectious, virus were seen for about nine days post-inoculation, and up to a maximum of 12 days.

Modelling using the study data indicated that regular asymptomatic lateral flow testing would diagnose infection before 70% to 80% of infectious virus had been generated, meaning that if isolation was triggered by the lateral flow test, it would decrease community transmission to others.

“I am delighted that the world's first Covid-19 characterisation study has completed with no serious adverse events or serious symptoms, demonstrating that a Covid-19 human challenge study is safe in healthy young adults,” said executive chairman Cathal Friel.

“The results, which have been made public today, have provided invaluable insights into Covid-19 disease progression.”

Friel said crucially, the study had now established a Covid-19 human challenge model, which could be “instrumental” in accelerating the development of future Covid-19 therapeutics.

“New variants, such as Omicron, often mean that vaccines and antivirals have to be quickly re-evaluated to ensure effectiveness.

“Human challenge studies could prove to be the fastest way to compare old and new vaccines and therapies.”

At 1238 GMT, shares in Open Orphan were up 8.85% at 20.14p.