Long COVID can take more than your breath away

COVID-19 has swept across the globe, taking the lives of millions in under two years. Hundreds of millions more have survived infection, but are still living with persistent health issues caused by the disease.

“We really have a pandemic of a different nature on our hands and we need to do something about it,” said Dr. Avindra Nath, a neuroimmunologist and researcher at the at the National Institute of Neurological Diseases and Stroke, during the Council for the Advancement of Science Writing’s New Horizons in Science briefing at the virtual ScienceWriters2021 conference. Nath and other researchers are studying why COVID-19 effects linger, and how best to help patients recover fully.

Lasting illness after infection, called Long COVID, long-haul COVID, or post-COVID syndrome, is characterized by symptoms such as serious breathing difficulty and fatigue, neurological issues such as “brain fog”—trouble concentrating—and permanent loss of smell and taste. Patients average about 40 years old, but adults aren’t the only ones who experience Long COVID.

“To say that it doesn’t affect children is truly, unfortunately, not true,” Nath said. For example, children sometimes develop a condition called multisystem inflammatory syndrome, which can cause general weakness, speech difficulties, and death due to brain injury. Determining the specific ways in which Long COVID affects the nervous system, whether through persistent viral infection or inflammatory damage, could guide efforts to develop effective treatments for people of all ages.

COVID-19 can affect the brain in many ways. About 80% of patients lose some or all ability to smell—and taste, since smell is a major component of tasting—as a result of injury to or destruction of neurons in the region of the brain devoted to smell. COVID-19 can also damage blood vessels in the brain, leading to stroke. Though not confirmed, it is thought that it may affect the brainstem, which controls basic functions such as breathing and digesting.

Vaccines substantially reduce the risk of infection and, in turn, the risk of developing Long COVID. Unvaccinated people are two times more likely to develop Long COVID than those who are vaccinated, according to a September study in The Lancet Infectious Diseases.

There is about a three-month window post-infection to help COVID-19 survivors avoid Long COVID, according to a September study in Clinical Infectious Diseases. After that, little improvement occurs. This applies to both those who initially have mild symptoms treatable at home, and those who have moderate or severe symptoms that require hospitalization. In the study, about 50% of survivors who had moderate or severe infection still had symptoms after one year, and about 20% of those with milder cases still had symptoms after a year.

Persistent symptoms can be more than some Long COVID patients can endure.

“It is with deepest sadness I must let you know my wife took her own life … after battling long-haul COVID for over a year,” the spouse of a patient wrote to Nath. The woman’s symptoms included neurological problems and pain that made sleeping virtually impossible.

“A lot of the experience of people with Long COVID will be, unfortunately, like the experience of people with many chronic diseases,” Dr. Zackary Berger, an internal medicine physician and public health researcher at Johns Hopkins, said in an interview. Ongoing symptoms can be challenging for clinicians to diagnose and treat, adding to patient frustration.

To help health care providers better understand Long COVID, Nath and his team are conducting a clinical trial to determine just how the condition affects the immune system. Study participants will be treated with either antibodies or hormones, which act on the immune system in different ways. Results from immune system, nervous system and brain function tests, as well as brain imaging, could help reveal the mechanism by which Long COVID acts on the body, and, in turn, what the best treatment approach is.

“I’m most interested in trying to see what we can do to intervene and change this disease and have disease-modifying therapies,” Nath said.