SARS‐CoV‐2, the causative agent of COVID‐19 disease, has resulted in the death of millions worldwide since the beginning of the pandemic in December 2019. While much progress has been made to understand acute manifestations of SARS‐CoV‐2 infection, less is known about post‐acute sequelae of COVID‐19 (PASC). We investigated the levels of both Spike protein (Spike) and viral RNA circulating in patients hospitalized with acute COVID‐19 and in patients with and without PASC. We found that Spike and viral RNA were more likely to be present in patients with PASC. Among these patients, 30% were positive for both Spike and viral RNA; whereas, none of the individuals without PASC were positive for both. The levels of Spike and/or viral RNA in the PASC+ve patients were found to be increased or remained the same as in the acute phase; whereas, in the PASC−ve group, these viral components decreased or were totally absent. Additionally, this is the first report to show that part of the circulating Spike is linked to extracellular vesicles without any presence of viral RNA in these vesicles. In conclusion, our findings suggest that Spike and/or viral RNA fragments persist in the recovered COVID‐19 patients with PASC up to 1 year or longer after acute SARS‐CoV‐2 infection.

SARS-CoV-2, the causative agent of COVID-19 disease has resulted in the death of millions worldwide since the beginning of the pandemic in December 2019. While much progress has been made to understand acute manifestations of SARS-CoV-2 infection, less is known about post-acute sequelae of COVID-19 (PASC). We investigated the levels of circulating SARS-CoV-2 components, Spike protein and viral RNA, in patients hospitalized with acute COVID-19 and in patients with and without PASC. In hospitalized patients with acute COVID-19 (n=116), we observed a positive correlation of Spike protein with D-dimer, length of hospitalization, and peak WHO score while viral RNA correlated with a tissue injury marker, lactate dehydrogenase (LDH). When comparing patients with post-COVID symptoms (n=33) and patients without (n=14), we found that Spike protein and viral RNA were more likely to be present in patients with PASC and in some cases at higher levels compared to acute COVID-19 patients. We also observed that the percent positivity of circulating viral RNA increased in the PASC positive individuals compared to acute COVID-19 group while Spike protein positivity remained the same. Additionally, we report that part of the circulating Spike protein is linked to extracellular vesicles without any presence of viral RNA in these vesicles. Our findings suggest that Spike protein and/or viral RNA fragments persist in the recovered COVID-19 patients with PASC, independent of their presence or absence during the acute COVID-19 phase.

The Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and its sublineages pose a new challenge to healthcare systems worldwide due to its ability to efficiently spread in immunized populations and its resistance to currently available therapies. COVID-19, although targeting primarily the respiratory system, is also now well established that later affects every organ in the body. Most importantly, despite the available therapy and vaccine-elicited protection, the long-term consequences of viral infection in breakthrough and asymptomatic individuals are areas of concern. In the past two years, investigators accumulated evidence on how the virus triggers our immune system and the molecular signals involved in the cross-talk between immune cells and structural cells in the pulmonary vasculature to drive pathological lung complications such as endothelial dysfunction and thrombosis. In the review, we emphasize recent updates on the pathophysiological inflammatory and immune responses associated with SARS-CoV-2 infection and their potential long-term consequences that may consequently lead to the development of pulmonary vascular diseases.

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The COVID-19 pandemic has challenged researchers to rapidly understand the capabilities of the SARS-CoV-2 virus and investigate potential therapeutics for SARS-CoV-2 infection. COVID-19 has been associated with devastating lung and cardiac injury, profound inflammation, and a heightened coagulopathic state, which may, in part, be driven by cellular crosstalk facilitated by extracellular vesicles (EVs). In recent years, EVs have emerged as important biomarkers of disease, and while extracellular vesicles may contribute to the spread of COVID-19 infection from one cell to the next, they also may be engineered to play a protective or therapeutic role as decoys or “delivery drivers” for therapeutic agents. This review explores these roles and areas for future study.