Fig. 5
From: Sex differences in severity and mortality from COVID-19: are males more vulnerable?
The possible factors in sex-biased mortality from COVID-19. COVID-19 has shown sex-biased mortality with higher death rate in males. This difference could be due to testosterone and estrogen differential effect on the immune system. Since females have two X chromosome, they have higher copy number of immune-related genes which provides a stronger immune response. The robust immune system in females better regulates viral infections, and consequently, lower mortality is observed. The stress endurance level is low in males compared with females, and this could also be a contributing factor for the sex-specific pathogenesis from COVID-19