SAN DIEGO (KGTV) – For the first time, a study suggests different COVID variants can lead to different long haul COVID symptoms.
Researchers in Italy looked at 428 patients who had been hospitalized with COVID and later developed long COVID. All the patients were infected early in the pandemic, by either the initial form of the virus or the first major variant, Alpha.
The two most common symptoms reported by long haulers, regardless of the variant, were fatigue and trouble breathing.
Beyond that, the study found those infected by the Alpha variant were more likely to report muscle aches, trouble sleeping, brain fog, and anxiety.
Long haulers who had been initially infected by the original strain, also known as the ancestral strain, were more likely to report loss of smell, difficulty swallowing, or hearing problems.
The findings will be presented at the European Congress of Clinical Microbiology & Infectious Diseases later this month.
“I think it's really interesting that the different variants seem to correlate with different long-term symptoms. It's almost not surprising because we know that some of the variants had a little bit of differences in terms of their acute symptoms,” said Dr. Lucy Horton, an infectious disease specialist not involved with the study who runs the post-COVID clinic at UC San Diego.
Other studies have identified changes in the symptoms that appear in the initial stage of the disease. Compared to earlier variants, Omicron is associated with fewer cases of lost smell and more reports of sneezing. But the Italian study is the first to identify a trend with long COVID symptoms.
Different variants grow best in different parts of the body. Delta grows best deep in the lungs, causing more coughing and fever in the initial stage of the disease. Omicron grows best in the throat and upper airways.
Dr. Horton says it makes sense those findings would apply to long COVID symptoms as well, but the Italian study did not examine Delta or Omicron.
“I think understanding whether those long COVID symptoms are different will be really important since we need to plan for caring for large numbers of patients, especially who were infected during Omicron,” she said.
The study found gender plays a major role in the risk of long COVID, a finding that’s been replicated in other research. Women were almost twice as likely to report long COVID symptoms as men.
“It's been hypothesized that maybe there's a hormonal effect, but that hasn't really been proven so far,” Horton said.
Part of the challenge of treating long COVID is that there are so many symptoms under one label. Other research has identified more than 200 long COVID symptoms.
But with more studies like the one in Italy, scientists can begin to develop subsets of long haulers, which will help as doctors find effective treatments, Dr. Horton said.
“If we can subtype different types of long COVID, we can better treat patients by knowing which therapies they may respond to,” she said.