Men at Increased Risk for Severe COVID-19

Increasing evidence shows that men tend to have more severe symptoms of COVID-19 and a higher death rate than women with the disease, reported a U.S. NIAID-funded clinical research study enrolled males and females who were admitted to the hospital with moderate or severe COVID-19.

As COVID-19 progressed in study participants, males, but not females, showed associated poor T-cell responses.

Likewise, T-cell responses declined with age in males but not females.  

Several key differences in immune responses were seen between males and females with COVID-19. Males had higher blood levels of several proteins called cytokines, which regulate the immune response, including two inflammatory cytokines known as IL-8 and IL-18, at the time of study enrollment (baseline) and over the disease course.

Males also had lower baseline activation of immune cells called CD8 T cells, which can recognize and help eliminate invading viruses.

By contrast, researchers identified elevated levels of a different set of cytokines in females, but not males, that were associated with worsening of the disease.

These findings reveal a possible immunological basis for the differences in disease outcomes between males and females with COVID-19 and provide a potential basis for taking sex-dependent approaches in the treatment of COVID-19, says the NIAID.