Study reveals main risk factors for long COVID

People who had multiple or severe episodes of COVID-19, and those who were not vaccinated when first infected, had a higher risk, according to a new study led by researchers at Stony Brook University. increased risk of developing long COVID.

The study looked at 2,522 people in the program who tested positive for COVID-19 between March 2020 and February 2024 and determined that 475 had long COVID. Of these, 403, or nearly 85%, have been repeatedly infected with the virus that causes COVID.

The study was conducted by researchers at Stony Brook University’s Renaissance School of Medicine in collaboration with the Stony Brook World Trade Center Health and Wellness Program.

Everyone in the study was considered essential workers and most were first responders. The program treats and monitors people with health problems related to the terrorist attacks of September 11, 2001.

“We found a significant association” between the risk of long COVID and multiple reinfections, severity and vaccination status at first infection, according to the report published this month in the journal “The Lancet Regional Health-Americas” .

The study indicates that a “large proportion” of participants who were not vaccinated at the time of their first infection suffered long COVID.

Senior author and professor at Stony Brook Sean Clouston said researchers took into account different medical conditions, but age and gender didn’t really make a difference unless they contributed to the severity of infections.

“We had younger people who had more severe COVID associated with higher risk of long COVID,” said Clouston, a professor in the department of family, population and preventive medicine at the Renaissance School of Medicine.

“It really wasn’t the age anymore, it was COVID.”

Long COVID, also known as post-acute aftereffects, presents with a number of symptoms ranging from brain fog, loss or alteration of taste and smell to wheezing, coughing and chest pain.

People who have persistent or new symptoms three months after contracting COVID-19 are classified as having long COVID, with symptoms lasting at least two months.

Experts say continued study of long COVID is vital because even though deaths and serious illnesses from COVID-19 have declined since the early days of the pandemic, many questions remain about the lingering impacts of an infection and these are still not fully understood.

“Long COVID is now a threat,” said Dr. Reynold A. Panettiere, Jr., vice chancellor of the Rutgers Institute for Translational Medicine and Science, who was not involved in the study.

“Before, it was death. People didn’t want to go to intensive care and be on a ventilator,” he said. “Now if you catch it and you get it more frequently, the risk of long COVID and lingering symptoms is greater.”

Although COVID-19 vaccines have played an important role in reducing the number of people who become seriously ill and die from the disease, they have not prevented or stopped infections, said specialist Dr. Benjamin Luft of Infectious Diseases and Director of Stony Brook World. Trade Center Health and Wellness Program, co-author of the study.

“Long COVID-19 has been so debilitating and so harmful that there really needs to be something that is effective against this, whether it’s a vaccine or a therapeutic treatment,” Luft said.

The overall number of people receiving the COVID-19 vaccine has declined compared to early years, with some people expressing frustration over its failure to prevent infections, even though the rate increased in 2024 compared to the previous year.

“Instead of saying, ‘We’re not going to get a vaccine,’ people should be demanding a better vaccine…a vaccine that prevents infection,” he said. “We need new and better strategies for next-generation vaccine development.”