Dr. Anthony Fauci, the nation's top infectious disease expert, says that a new study could explain the wide range in severity of COVID-19 symptoms that different patients experience, The Miami Herald reported.
Since the beginning of the pandemic, doctors have been baffled about the unpredictable ways in which SARS-CoV-2, the pathogen currently being referred to as the "novel coronavirus," affects different patients. While some infected with the virus have displayed no symptoms, other cases have ranged from mild to fatal.
A new study published in the journal Science that Fauci feels could possibly explain why. SARS-CoV-2 is one of many pathogens in the coronavirus family, and not all of them cause fatal illnesses. Many of them cause nothing more than a mundane common cold.
When a virus invades a person, the body's immune system deploys a variety of tools to fight both the current infection and to guard against a repeated one. Those tools include antibodies and T-cells.
Fauci used a military metaphor to describe the roles of the two systems.
"If you look at it metaphorically as an army with different levels of defense, the antibodies prevent the virus from getting in. So that's kind of like the first line of defense. For those viruses that do escape and infect some cells, the T cells come in and kill the cells that are infected or block them," he said.
In the case of COVID-19, the respiratory illness caused by SARS-CoV-2, it seems that a fair number of test subjects in the recent study remembered having been previously exposed to illnesses caused by other pathogens in the coronavirus family, such as the common cold.
Among those subjects, their immune systems had T-cells that were equipped to fight off the microbe that causes the fatal respiratory illness.
According to Dr. Shane Crotty, a virologist at the La Jolla Institute for Immunology and senior author on the Science study, just about every human will experience multiple common colds in their life, including many caused by coronaviruses. However, only about half of the people exposed to another coronavirus will develop immunity to "the" coronavirus.
Angela Rasmussen, a virologist at Columbia University, noted that the medical community's understanding of this pathogen -- and the immune system's reaction to it -- is in its infancy. Still, she welcomes the recent findings, as well as further research that can build on them with a view toward developing a vaccine or even a cure.
"If there's anything that can give us an edge in fighting it, even within our own bodies and immune systems, that to me is great news and is very promising," Rasmussen said.