A Stanford study shows that in severely ill COVID-19 patients, “first-responder” immune cells, which should react immediately to signs of viruses or bacteria in the body, instead respond sluggishly.
Now, a study by investigators at the Stanford University School of Medicine and other institutions has turned up immunological deviations and lapses that appear to spell the difference between severe and mild cases of COVID-19.
That difference may stem from how our evolutionarily ancient innate immune system responds to SARS-CoV-2, the virus that causes the disease. Found in all creatures from fruit flies to humans, the innate immune system rapidly senses viruses and other pathogens. As soon as it does, it launches an immediate though somewhat indiscriminate attack on them. It also mobilizes more precisely targeted, but slower-to-get-moving, “sharpshooter” cells belonging to a different branch of the body’s pathogen-defense forces, the adaptive immune system.