An enduring coronavirus mystery: Why some people get really sick, and others don’t get any symptoms.
Nobody knows why. Finally, scientists discovered some clues.
A Stanford study found that immune cells respond sluggishly to signs of viruses in severely ill COVID-19 patients.
In a healthy body, immune cells rapidly sense viruses and launch an immediate attack on viruses.
The worse the case of COVID-19, the less effective some immune cells were in responding to the infection.
How to speed up immune cells in the body?
The body increases temperature to speed up immune cells.
The fever response is a hallmark of all infections.
The body is considered to have a fever if the temperature rises 1°C (38°C) above normal.
A fever can help the immune system fight infections in two ways.
First, a higher temperature speeds up the functioning of immune cells.
Second, higher body temperatures make the body harder for viruses to thrive in. Viruses are more infectious in cold winter temperatures.
The increase of 1 to 4 °C on body temperatures that occurs during fever is associated with improved survival and resolution of many infections.
The use of antipyretic drugs to diminish fever correlated with a 5% increase in mortality in humans infected with influenza virus.
Sharon S. Evans et al. Fever and the thermal regulation of immunity: the immune system feels the heat, Nat. Rev. Immunol. 15(6):335-349, 2015
Currently, the US leads the world in cases and deaths of COVID-19 infections.
Something is wrong in the US besides the lockdown.
Sweden COVID-19 death rate lower than Spain, Italy and U.K., despite never having lockdown.
There is a blind spot in American public health: decreased body temperatures of Americans.
Stanford researchers found that average human body temperature in the US has decreased since the 1800s.
The body temperature of men born in the 1990s was on average 1.06 F lower than that of men born in the early 1800s.
Similarly, the body temperature of women born in the 1990s was average 0.58 F lower than that of women born in the 1890s.
Each degree of body temperature matters a lot to the immune system.
In the immune system, T cells play a central role in the immune response.
In mice, T cells jump into the infection sites after body temperature rises.
Scientists grew T cells from mice, and raised the temperatures of these cells from the normal body temperature of 37 °C to a fever temperature of 40 °C.
A 3°C rise in temperature triggered the T cells to start producing heat-shock proteins.
These heat-shock proteins promoted the migration of T cells to infection sites.
Sedentary lifestyles and ice-cold drinks can reduce the body temperature.
Global warming is a public health issue.
Body temperature cooling is an ignored health issue.
