What are the changes to the ‘average’ older person that makes them more susceptible?
The first change is to the immune system – in the innate immune system and the adaptive immune system. The adaptive immune system has specific antibodies that the body makes to specific viruses to help clear them. This system tends to become a bit untargeted and under effective in the average person with age.
The second change is in the respiratory system. The lungs in older people become stiffer and less capacious, and the muscles in the chest wall become weaker. This is thought to be partly because of accumulated damage, such as smoking pollution, and partly due to central ageing leading to the buildup of senescent cells that cannot divide any more but secrete signals which lead to damage.
The third change is the accumulation of other diseases which are more likely the longer you have been on the planet – particularly cardiovascular disease – which effects the heart’s ability to cope with infection; diabetes – which in the case of coronavirus is much aggravated by the virus, causing sugars to go sky high which effects all cells functions; and kidney problems as kidney function, like lung function tends to decline with age and so impairs the ability of the body to handle water, which appears to be really important in coronavirus patients.