Since early statistics began to emerge from China, it seemed that COVID-19 tended to affect older people more than younger ones. And now, data from Italy is matching this finding, with the average age of those already dead standing at around 79.5. But why is this? Why does COVID-19 disproportionately affect older people?
To begin, as we get older, our immune systems tend to deteriorate, meaning that they are less likely to fight off infections such as those caused by COVID-19. According to Sean Leng, a professor of medicine at John Hopkins University, “Studies over the years have shown that in most people, their immune function is pretty okay in their 60s, or even in their 70s. The immune functions go down rather quickly after age 75 or 80.”
As the number of white blood cells available to find and eradicate infections declines with age, older people are at a higher risk of having a dangerous immune response known as a cytokine storm. Although cytokines are proteins that signal the body to better fight against infection, during a storm, the body produces an excess of these causing severe inflammation, a high fever and oftentimes, organ failure. This means that among older adults, their leading causes of death from COVID-19 is respiratory failure likely followed by the cytokine storm.
Even before COVID-19 sets in however, a weaker immune system also means a higher susceptibility to chronic diseases such as diabetes, heart conditions and cancer that compound to further weaken one’s ability to fight off infection. More common in older people, this factor is plays a strong role when considering recent statistics from Italy demonstrating that 48.5% of people who died had three or more underlying illnesses while 25.6 had two, and 25.1% had at least one- all in all meaning that just 0.8% pf deaths had no other underlying illness.
Other factors that may leave older people more susceptible to negative outcomes from COVID-19 too. For example, older people may be less able than younger ones to cough and sneeze, making it harder for them to clear their airways which may allow the virus to spread more efficiently. More than this, compounded lung damage in older adults from smoking or living in polluted air may also increase their vulnerability.