When the body first encounters a virus or a bacterium, the immune system ramps up and begins to fight the invader. Usually, the stronger this immune response, the stronger the chance of vanquishing the infection, which is partly why children and younger people are less vulnerable.
In some cases — as much as 15 percent of people battling any serious infection, according to Dr. Cron’s team — the immune system keeps raging long after the virus is no longer a threat. It continues to release cytokines. These cytokines attack multiple organs including the lungs and liver, and may eventually lead to death. In these people, it’s their body’s response, rather than the virus, that ultimately causes harm.
Some drugs (e.g. tocilizumab) are currently being used and tested to battle these so called cytokine storms.
