Birmingham , Jan 4 : A recent study has determined that Covid-19 patients might be helpful for clinicians to better understand how the unknown SARS-CoV-2 virus acts.

According to a study published in the Journal of Clinical Investigation, many infected patients remain asymptomatic or have mild symptoms. Others, especially those with comorbidities, can develop severe clinical disease with atypical pneumonia and multiple system organ failures. Since the first cases were reported in December 2019, the SARS-CoV-2 virus that causes COVID-19 has surged into a pandemic, with cases and deaths still mounting. Ongoing observational clinical research has become a priority to better understand how this previously unknown virus acts, and findings from this research can better inform treatment and vaccine design.

The University of Alabama at Birmingham researchers, led by first-author Jacob "Jake" Files and co-senior authors Nathan Erdmann, M.D., Ph.D., and Paul Goepfert, M.D., have now reported their observational study, "Sustained cellular immune dysregulation in individuals recovering from SARS-CoV-2 infection."

In a commentary on the UAB study, published in the same issue, Phillip Mudd, M.D., Ph.D., and Kenneth Remy, M.D., both of Washington University, wrote, "The importance of these studies to provide context for the interpretation of immune responses generated by participants in COVID-19 vaccine trials, including how those responses change over time, cannot be over-emphasized. This information will be key in potential modifications to existing COVID-19 vaccines and treatments."

The UAB researchers obtained blood samples and clinical data from 46 hospitalized COVID-19 patients and 39 non-hospitalized individuals who had recovered from confirmed COVID-19 infection. Both groups were compared to healthy, COVID-19-negative controls. Importantly, most individuals in the hospitalized group had active SAR-CoV-2 viruses in their blood and were in the hospital at the time of sample collection. All individuals in the non-hospitalized group were convalescent at the time of sample collection.

From the blood samples, researchers were able to separate specific immune cell subsets and analyze cell surface markers. From this complex information, immunologists can analyze how each individual's immune system is responding during infection and during convalescence. Some of these results can reveal whether immune cells have become activated and exhausted by the infection. Exhausted immune cells may increase susceptibility to a secondary infection or hamper the development of protective immunity to COVID-19.