In a high security laboratory in Sydney, where a select group of researchers go to extreme lengths to work with samples of blood and swabs containing Covid-19, virologist Stuart Turville found a unicorn.
“A beautiful, immunological unicorn,” Turville, an associate professor with the Kirby Institute at the University of New South Wales, said.
“We found him when we were analysing samples from the Red Cross blood bank from people who have had Covid. And he had the most amazing Covid response I’ve ever seen.”
The unicorn is a 50-year-old father of three named Damian living on the NSW Central Coast who developed symptoms of Covid-19 in March. His symptoms were severe enough to take him to the hospital emergency department, but after being given oxygen he was sent home the same day. Bizarrely, when he was tested for the virus with the gold-standard PCR nasal swab, the lab kept returning a negative result for Covid-19.
“When they initially diagnosed him they couldn’t find virus in his nasopharyngeal area [the upper part of the throat behind the nose],” Turville told Guardian Australia.
“So they kept on swabbing him and swabbing him, but they couldn’t find it. He kept on saying to them, ‘Look, I’m sick, my son’s got it, I have to have it’. And it was only when they looked at his blood, his serum, they said; ‘Oh, yeah, you’ve had it. And you’ve got the most amazing immune response’.”
Most people who have Covid-19 develop a decent immune response.
“But this guy’s response is 100 to 1,000-fold that,” Turville said.
“His response is that good. To put it in context, we are eight or nine months out since he was infected. And he still ranks in the top 1% of responders, so what that means is if we could ever bottle a vaccine that could mimic his response, you’d want to do it. I would say that we’re going to see him responding just as well probably a year out, and maybe after about two years we might start to see some response decay.”
Usually, patients who show a particularly robust immune response to Covid-19 end up in an intensive care ward. In many of these severely unwell patients, the immune system overreacts in what is called a “cytokine storm”. Cytokines are proteins that can trigger an inflammatory response so aggressive that not only are virus cells attacked but cells in the blood vessels, urinary tract, organs and blood vessels are also destroyed, leading to organ failure and sometimes death. For some reason Damian’s response, though strong, did not bring on such an aggressive storm.
“That’s something we’re trying to get our head around,” Turville said.
Not only is Damian’s immune response lasting but it has not weakened much over time, offering strong ongoing protection against the virus, which is what makes him so unique. A Public Health England study found that while most people who have the virus are protected from reinfection for at least five months, some are reinfected, and even asymptomatic people can harbour high levels of the virus in their noses and mouths, and therefore risk passing it on to others.
After being told about his unicorn status, Damian offered himself up for medical research. Turville estimates that Damian has donated blood and plasma upwards of 15 times.
Hundreds of recovered Australians like Damian have now donated blood so their plasma, teeming with antibodies, can be separated out and used to make batches of serum through a collaboration between the Kirby Institute and manufacturer CSL. This serum is then given to severely unwell patients around the world to treat their disease.
“It also means that if the virus…