CHICAGO — An infectious disease fellow at Lurie Children’s Hospital, who was captivated by the SARS outbreak, received her PhD in coronaviruses.

Dr. Taylor Heald-Sargent has always found viruses fascinating.

“I’ve always been interested in viruses, I find them fascinating,” Heald-Sargent said. “(SARS) was a hot topic and I found it really intriguing.”

Now, she’s putting her studies to good use during an outbreak experts saw coming, but not on this scale.

In the last two decades, three novel coronaviruses have invaded the human population: SARS-COV, MERS and now SARS-COV-2. SARS-COV-2 has not been seen by human bodies before and causes COVID-19.

“So, really it can overwhelm the population when no one has protection,” Heald-Sargent said.

In most, the immune system kicks in and clears the infection. However in older people, the results can be fatal.

“The immune system almost goes out of control and it’s called a cytokine storm and it gets way overactive and it can actually damage the body,” she said.

On the opposite end of the age spectrum, children seem to be spared from severe infection. But can the virus lay low and then re-emerge in the body?

“Coronaviruses don’t hide away from the immune system in your body and then come out at times of stress, or come out at a later time that’s not their life cycle. They come in and infect. It’s usually acute and then they go away,” Heald-Sargent said.

There have been anecdotal reports of recovered patients experiencing a second infection, but Heald-Sargent said that’s not likely.

“What seems more likely is that we’re just not able to detect the virus and they’re actually still infected, because the virus may still be replicating in their lungs and we’re only testing their nose and throat and it might be on it’s way out but it hasn’t completely gone away,” she said.

It’s still unknown whether COVID-19 will cause any long-term damage to the body, particularly the lungs.