Researchers are now focusing on understanding the long-term effects of COVID-19, which can cause significant morbidity and mortality. Two studies published in The American Journal of Pathology have identified potential pathways for drug treatment in the chronic phase of the disease.

The first study examined post-viral lung disease and proposed a drug therapy for long-term COVID-19 and related conditions. Autopsies of patients performed weeks after COVID-19 onset revealed a pattern of lung remodeling, immune activation, and mucinous differentiation. The study suggested aiming at specific cellular and molecular targets for therapy.

In the second study, a hamster model of human COVID-19 was used to investigate coagulation abnormalities and vascular damage associated with severe cases. Results indicated that immune dysfunction contributes to vascular damage, leading to potential therapeutic opportunities.

Washington University School of Medicine in Saint Louis' Dr. Michael J. Holtzman, who led the first study, emphasized that these findings provide insights into the pathogenesis of post-viral lung disease and lay the foundation for developing targeted therapies.

"Taken together with the results of our previously published animal models of post-viral lung disease, these studies deliver a roadmap for the pathogenesis of post-viral lung disease and the basis for a disease-modifying strategy for long-term COVID-19 and related post-viral conditions," Holtzman said in a press release.

"The research defines a pattern of disease that implicates specific cell and molecular targets for therapy. Indeed, we are now developing a drug therapy that aims precisely at fixing those targets," he added.

University of California, Davis' Dr. Erin E. Ball, leading the second study, suggested that indirect vascular damage resulting from immune dysregulation is a major contributor to vascular damage in severe COVID-19 cases. Targeting the dysregulated immune system could be an effective approach to counteracting COVID-19.

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"These findings suggest that indirect vascular damage, possibly secondary to immune dysfunction, is a major contributor to vascular damage observed in SARS-CoV-2-inoculated hamsters and potentially severe COVID-19 infection in humans," Ball explained.

These studies shed light on potential treatment pathways for long COVID and highlight the importance of addressing the chronic phase of the disease.