New Insights into Why Men Are More Vulnerable to Severe COVID-19

Researchers from Umeå University in Sweden have uncovered critical findings that help explain why men tend to experience more severe forms of COVID-19 compared to women. The study, published in the European Journal of Immunology, reveals that immune responses differ significantly between sexes, particularly involving immune cells called neutrophils and inflammatory signaling molecules known as cytokines.

Although the overall number of COVID-19 cases is similar among men and women, data shows that men are three times more likely to require intensive care. Severe COVID-19 is characterized by an overactive immune response—specifically, an excessive recruitment and activation of neutrophils in the lungs. These white blood cells, normally essential for fighting infections, can cause tissue damage when overactivated.

To investigate the underlying mechanisms, the research team analyzed blood samples from over 200 Swedish COVID-19 patients. They found that patients with severe disease exhibited higher levels of cytokines that promote neutrophil activation, along with increased markers of neutrophil activity. Interestingly, the increase in a specific cytokine, IL-18, as well as neutrophil activation markers, was notably higher in men than in women.

This sex-dependent difference in immune response offers a new understanding of why men are more likely to develop critical illness from COVID-19. The findings are particularly relevant as they could influence future treatment strategies aimed at controlling neutrophil activation to reduce lung damage. By precisely mapping these immune responses, especially the sex-related variations, scientists hope to develop targeted therapies that could improve outcomes for severely ill COVID-19 patients.

The study emphasizes the complex nature of immune responses to viral infections and highlights the importance of personalized approaches in treating COVID-19. Future research aims to further explore these sex-related differences and verify findings in larger patient cohorts.

Overall, this breakthrough enhances our understanding of the immune mechanisms behind COVID-19 severity and underscores the importance of considering sex differences in both research and clinical treatment approaches.

Source: [https://medicalxpress.com/news/2025-05-discovery-men-affected-severe-covid.html]