n 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 emerges again in Australia and takes off, we’re battle ready,” Turville said. “Damian’s serum has contributed to many batches of these CSL products. Whenever we get a batch of serum that is particularly amazing, we say ‘OK, he’s in this batch’. That’s how impressive his response is.” Some of the findings about Damian have been published in a pre-print paper about “high and elite responders,” which describes how “patients with high and robust Covid-19 responses were more likely male, hospitalised, and of older age”. It is work like this that has researchers from the Kirby Institute’s containment lab – more scientifically referred to as a Physical Containment Level 3 (PC3) Laboratory – occupied at times until 3am in the morning. They also examine samples taken from returned travellers in hotel quarantine, growing the different variants in the lab to see how they behave. It is one of a handful of high-security labs around Australia where the virus is being studied. Researchers from Prince of Wales Hospital and the Garvan Institute collaborate with the Kirby Institute to analyse samples and to work on treatments in the containment lab. Previously used for HIV research, the containment lab has been retrofitted to ensure Covid-19 has no chance of escaping. Researchers need to walk through three negative-pressure chambers in order to enter the main laboratory where they work on the virus. The negative pressure creates a vacuum that sucks air inwards, making it impossible for any virus particles to escape. Along the way through each chamber, the researchers put on layers of personal protective equipment including gloves, which they tape to the gown they wear, so that there is no risk of the gown riding up and exposing their wrists. “If you look at images of Dustin Hoffman in Outbreak, you’ll see they’ve done the same and tape down their gloves, so that’s what we do,” Turville said. “Not because we watch Outbreak but to reduce contamination risk.” Once they enter the central lab they put on their cutting-edge halo masks, which cost $30,000 each and have inbuilt nano-filters and a rechargeable battery. The respirators seal off the face and connect to the hooded, waterproof disposable gowns worn by the researchers, allowing them to breathe safely. Before stepping into the final module of the laboratory, which Turville describes as a submarine, the researchers put on a final piece of gear. “Bunnings gumboots,” Turville says. By this point, the most frustrating thing that can happen is realising he has forgotten to bring something into the laboratory with him, because going through the process of decontamination, removing and putting on protective gear takes so much time. “But the modules we work in have these massive portholes through which we can see and communicate with people on the other side,” Turville said. “We use big glass whiteboards and if someone walks past, they will write ‘Do you need anything?’ on it. And we can write a shopping list in response, and they will fill up a trolley and pass it through. But when you forget something, it’s really annoying.” Challenges like layers of hot, sweaty gear and arduous personal protective gear procedures aside, Turville said the team of researchers who he works with is one of the things that keeps him going after working upwards of 12-hour days. “It’s been really tough for the team in terms of the stress of this work, the hours they have to put in, and all of the things they have sacrificed,” Turville said. “The people I work with are just really clever, they’re clever at genetically engineering cells, they’re really good at manipulating cells and drug screening. “And when they go home they can know they are working on a part of a jigsaw puzzle that will help save people’s lives. I just really want to see their work highlighted and appreciated, because they’re such great people and they work so hard.”