Around 400 million people worldwide are believed to have long COVID, and 17.8 million of those are in the U.S., according to medical journal Jama.
The state with the highest rate of long COVID is West Virginia with 10.6 percent of its population having experienced the illness, according to data from the Centers for Disease Control and Prevention.
Other states with high rates of long COVID included Montana, Alabama, North Dakota, Oklahoma, and Wyoming.
States with the lowest rates of long COVID were Maryland, Vermont, Hawaii and Rhode Island.
It was found that 6.9 percent of the U.S. population had experienced long COVID as of early 2023, according to a study published earlier this year.
Dr. Linda Geng, the co-director of Stanford University‘s Post-Acute COVID-19 Syndrome Clinic, told Newsweek that while the CDC data requires further study and is likely multifactorial, it is “clear that the pandemic has exacerbated pre-existing healthcare inequities.”
She said that the states with the highest prevalence of long COVID “tend to have more rural communities and rural communities face structural and social challenges to healthcare that have compounded worsened outcomes during the COVID-19 pandemic.”
Geng added that those states also tended to “have lower rates of COVID-19 vaccination, which has been shown to be protective against the development of Long COVID.”
The states with lower rates of health issues post-COVID had higher rates of COVID-19 vaccinations, she said.
A study in September this year found that the COVID-19 vaccine had reduced the risk of developing long COVID.
When the pandemic first began, around 10 percent of those who caught COVID-19 went on to develop long COVID, but that risk is now at 3.5 percent among vaccinated people, a Yale Medicine study found.
Other than the vaccine helping to bring down the risk of developing long COVID, Stanford University Professor of Medicine Dr. PJ Utz told Newsweek that there have also been important advances in long COVID research.
“We now know that a significant proportion of long COVID patients have evidence for ongoing immune activation, including abnormalities of blood proteins called complement, dysregulation of blood clotting pathways, and activation of endothelium, which lines blood vessel,” he said, adding that this could be linked to cardiovascular disease and brain disease.
He said that some patients “develop autoantibodies, supporting large epidemiology studies demonstrating that the incidence of autoimmunity increases after infection.”
The virus can also be found in tissues such as the gut a long time after infection, and other studies link a reactivation of Epstein Bar Virus, the virus behind mono, otherwise known as glandular fever, to long COVID, Utz told Newsweek.
Rogelio V. Solis/AP
Discussing future development of long COVID treatment, the Stanford professor said that the “pace of research on long COVID is incredibly fast.”
“For example, if lab testing shows that inflammation or thrombosis is dysregulated in a patient, therapies that target the immune or clotting systems, respectively would be targeted,” he said.
Globally, the condition is estimated to have an annual economic impact of approximately $1 trillion, around one percent of the global economy, a study in Nature Medicine found.
It remains a highly prevalent condition, Geng said, because COVID-19 is still prevalent in the U.S. Long COVID is a condition that can last for years, she said, and there are “no curative treatments currently available.”
The condition has also been found to be more prevalent among women, according to CDC data.
Between August 20 and September 16 this year, around 6.8 percent of all women in the US. and 3.7 percent of men were currently experiencing long COVID symptoms.
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