A detailed comparison of COVID-19 cases has finally given us insight into why some individuals cannot smell the virus that has brought the world to its knees.
A research team led by the Wellcome Sanger Institute and University College London in the UK analyzed the genetic activity of nasal tissue and blood from people who failed to develop SARS-CoV-2 infection and discovered new immune responses: Strong frontline defense.
The vaccine and booster vaccines have radically reduced the risk of death and serious complications from COVID-19, but they do little to prevent the virus from gaining a foothold in the nose and respiratory system.
For most people, this temporary facility leads to a miserable week or so of runny noses, coughs and relatively mild body aches.
But for a lucky few, the infection progresses so quickly that the body barely has time to feel even a single ‘achu’. For all intents and purposes, despite the ongoing global pandemic, few individuals have remained completely coronavirus-free.
It is unclear why some people are better protected than others, and field investigations are complicated by difficulties in pinpointing the moment of exposure.
To overcome this obstacle, researchers implemented the following: challenge trialUnder strict laboratory conditions, 36 healthy volunteers aged 18 to 30 years were intentionally infected with the pre-alpha strain of SARS-CoV-2.
Crucially, 16 of the participants had never been vaccinated and showed no signs of previous SARS-CoV-2 infection.
“This was a very unique opportunity to see what the immune response is like in adults with no prior history of COVID-19 in a setting where we can control for factors such as time of infection and comorbidities.” Called Quantitative systems biologist Rik Lindeboom (now Netherlands) Cancer Research Institute.
Blood and nasal swabs taken from volunteers up to a year after infection were analyzed using single-cell RNA sequencing, providing a timeline that provides unprecedented detail about the activities of hundreds of thousands of individual cells.
From this particular data set, the team identified three categories of infections: transient, persistent, and abortive. It was this third group that discovered the body’s secret weapon to prevent COVID-19.
While most people mount a rapid immune response to invading viruses in the blood, these volunteers showed a subtle but much faster response in nasal tissue, including activation of mucosa-associated constant T.MAIT) cells and inflammatory white blood cells are reduced, eliminating viruses before they can invade.
Researchers also saw increased expression of the HLA-DQA2 gene in nasal cells before vaccination. Previously connected Mild or asymptomatic SARS-CoV-2 infection.
“These findings shed new light on the important early events that allow the virus to become established or quickly clear it before symptoms appear.” Called Marko Nikolić, lead author of the study and respiratory medicine scientist at University College London, said:
“We now have a much better understanding of the full range of immune responses, which could provide a basis for developing potential treatments and vaccines that mimic these natural protective responses.”
As successful as public health programs have been in curbing the worst impacts of the COVID-19 pandemic, the most vulnerable people in our communities remain at risk of long-term health problems and death from a virus that is content to continue spreading and adapting. .
Understanding how human biology responds to viral attacks is critical if we are to fight not only this ongoing threat, but also the even more lethal diseases we may face in the future.
This study nature.
