Compared to traditional forms of pneumonia, pneumonia from the novel coronavirus (COVID-19) develops over a longer period of time and lasts longer, according to a study in Nature.
Researchers from Northwestern University School of Medicine compared lung cell samples from more than 85 hospitalized patients with COVID-19 pneumonia to more than 200 hospitalized patients with pneumonia from other sources. Combining these results with foundational studies, they believe SARS-CoV-2, the pathogen that causes COVID-19, burrows deep in the lungs of people who develop severe respiratory infections from the virus. Once there, SARS-CoV-2 appears to take over immune function. White blood cells and immune helpers that rush to infection sites to coordinate recovery appear to instead ferry SARS-CoV-2 to neighboring lung cells. The researchers believe this altered immune response explains why COVID-19 pneumonia takes longer to develop and extends hospital stays. In this study, the average length between a patient feeling sick from COVID-19 and requiring breathing support was 6-12 days. For people with similar complications from the flu, the range was 1-3 days or shorter.
To accelerate recovery from severe COVID-19 lung infections, the researchers will test treatment to restore immune function. The research was supported by the NHLBI.