April 27, 2023 – A brand new study shows that individuals with Long COVID respond in a different way to COVID vaccines and that the condition could also be attributable to immune system dysfunction – possibly explaining why some people have symptoms for months while others get better and resume normal lives.
The study compared individuals who had already had Long COVID with individuals who had recovered from the virus. Both groups had not been vaccinated before the study. When researchers analyzed blood samples after people received a primary dose of vaccine, they found that individuals with Long COVID and folks who had already recovered from the virus initially had similar immune responses. But after 8 weeks, the Long COVID group's immune response was still elevated, while the opposite group's response had waned.
The Long COVID group also showed an extra immune response that attempted to fight the virus in a secondary way that the researchers didn't expect. Both groups initially showed a rise in antibodies within the blood that primarily goal the coronavirus's so-called “spike” protein, which allows the virus to invade healthy cells. However, the Long COVID group also showed a longer-lasting, enhanced immune response that attempted to fight the a part of the virus related to its replication.
“Theoretically, the production of these antibodies could mean that people are better protected against infection,” said researcher Catherine Le, MD, in a opinion“We also need to investigate whether the increased immune response corresponds to the severity or number of long COVID-19 symptoms.”
Le is co-director of the COVID-19 recovery program at Cedars-Sinai Medical Center in California, where the study was conducted.
The study participants agreed to take part in long-term COVID research at Cedars-Sinai in Los Angeles in September 2020. The latest evaluation was published earlier this yr in BMC Infectious Diseases This included 245 individuals who had long COVID and 86 healthcare employees who had recovered from COVID but didn't have long-term symptoms.
For the study, Long COVID was defined as symptoms that lasted longer than 12 weeks. Common Long COVID symptoms include fatigue, shortness of breath and brain dysfunction equivalent to confusion and forgetfulness.
The authors said it was unclear why the 2 groups showed different immune responses, and in addition identified that their study was limited by a small sample size. Their study of blood samples is ongoing. The goal is to seek out a technique to diagnose Long COVID with a laboratory test and to higher understand the causes of the disease.