A delayed immune response could make COVID-19 even more deadly for older people. A new study found signs that genes that trigger an immune response in older people are activated more slowly than in younger people. At the same time, genes that must turn off the immune system so that the inflammatory process does not get out of control are less active in men.
The immune response of older people to COVID-19 may be three days delayed compared to younger people, according to a new study – and this may explain why the death toll among this age group was so high.
With age, the immune system begins to deteriorate, says Daily Mail.
After analyzing about 500 swabs taken from coronavirus patients and controls, researchers at the University of Washington found key differences that indicate that the immune response in older people is slower than in younger people.
It’s impossible to say for sure why a virus that causes no symptoms in some who contracted it is so deadly to others, but new research offers some clues.
Data from the Centers for Disease Control and Prevention (CDC) in the United States shows that nearly a third of deaths occur in people aged 85 and over. Another 26 percent of those who died were between the ages of 75 and 84.
As the Daily Mail points out, every year, older people get pneumonia and die from infections like the flu and all kinds of other respiratory infections that would be unpleasant for young people, but not particularly dangerous. And overall, the deadly impact of the coronavirus on older people is in line with what we know about aging and infections: older people generally have weaker bodies, including their immune systems.
Much of the research to determine whether and how humans can develop immunity has focused on T-cell and B-cell activity. The former are targeted weapons, honed to combat specific infections and to instruct the latter, the B cells, to begin creating another specialized weapon – antibodies.
Both types of cells serve as part of the adaptive immunity of the human body, part of the immune system that develops throughout life in response to pathogens that people encounter while moving around the world.
When it comes to protecting against coronavirus when we first encounter it, “we are dealing with an innate immune system much more than an adaptive one,” lead author Dr. Alex Groenninger told DailyMail.com.
As the researchers explain, we are born with our innate immune system, which is made up of crude yet effective tools to block infection, including tiny white blood cell cells such as interleukins and cytokines. These cells are not designed to fight any specific pathogens, but will attack all extraneous pathogens in the body.
By analyzing nasopharyngeal swabs from hundreds of people who have tested positive and negative for coronavirus, Dr.Greninger and his team were able to sequence genomes and see exactly which genes were turned on or off in response to the virus.
In addition, they could see how brightly the genetic switches coding for different immune cells turned on, depending on the age, gender and viral load of each person.
According to Dr. Groeninger, the ability to quickly build up the immune system is much less pronounced in older people than in other age groups. This slow immune response gives the virus a chance to gain a foothold and multiply before the body notices. Older adults also have a higher baseline level of inflammation, so once their immune systems do respond and flood what may be multiple foci of infection by then, the additional inflammation that occurs can quickly become severe and fatal.
As older adults struggle to turn on the immune system, nasal swabs taken from men who have developed COVID-19 showed weaker gene activity that could turn off the immune response.
Without the proper functioning of the switch, inflammation caused by immune cytokines can last much longer than it should in men, affecting their bodies as well, but in a different mechanism than that which is fatal for many older adults.