Vaccination Could Reduce Risk of Long COVID, Study Shows

Feb. 15, 2023 – After studying thousands of people’s symptoms post-COVID-19, researchers have found that getting vaccinated could potentially reduce the risk of long COVID. 

The new study – which looked at patients 3 months after their COVID-19 infections across pre-Delta, Delta, and Omicron variants – at first saw that long COVID symptoms were more common in the pre-Delta period than in the Delta and Omicron periods. But these differences across variants became less important when researchers adjusted for vaccination status, suggesting that the vaccine could play a key role in lessening the risk of long COVID and making its symptoms less severe. 

Another important finding of the study, from researchers at Chicago’s Rush University Medical Center and the University of California San Francisco and published in the journal Clinical Infectious Diseases, was the sheer number of people post-COVID-19 who reported severe fatigue. 

“Mild fatigue is much different than severe, life-impacting fatigue,” lead author Michael Gottlieb, MD, said at a media briefing Wednesday. “One in eight affected with COVID had severe, prolonged fatigue at 3 months. … That speaks to the impact we’re seeing as a society.” 

The study included 2,402 COVID-positive and 821 COVID-negative people, with 463 falling into the pre-Delta category, 1,198 during Delta, and 741 during Omicron. 

The authors did not weigh how severe the  patients’ initial COVID infections were versus their prolonged symptoms, but Gottlieb told reporters that the group is currently working on supplemental survey research to see if there are any parallels between the two. 

Gottlieb said the research team is continuing to follow patients beyond the 3-month mark, to see what the paths of their symptoms look like. Some early data, he said, shows patients’ symptoms going in both directions: Some people who have minimal symptoms at 3 months might convert to severe symptoms at 6 months, and others with severe symptoms at 3 months might be better at 6 months. 

All of these lingering questions, including how reinfection plays into long COVID, will be the focus of future research for Gottlieb’s team. 

“We need to understand long COVID better, and we need to define it better,” Gottlieb said. “Long COVID isn’t a singular concept, there are different phenotypes and versions of it. As researchers, public health leaders, and as a society, we need to better understand what people are going through.”