Some COVID long-haulers have seen their symptoms ease or even vanish after receiving one of the mRNA vaccines (currently, those from Pfizer and Moderna). This has raised questions regarding the mechanisms at play.
“Most long-haulers aren’t affected by vaccination, but maybe 10 percent get unexpectedly better — like someone turned on the lights,” says functional-medicine internist Leo Galland, MD.
There are several theories about what might be occurring, including that the vaccines may somehow “reset” a glitchy immune system or provoke a psychosomatic response. The more likely explanation, however, is that some long-haulers battle a persistent infection with the SARS-CoV-2 virus, says Galland, and the vaccine boosts their immune response.
“The theory has been circulating for decades that autoimmune disease is caused by a lingering infection,” he explains. There is evidence that COVID viral proteins may persist in the gut and in immune cells in the blood, even after the virus has become undetectable in nasal swabs.
There is precedence for this theory. Studies, clinical trials, and patient surveys have shown that antibiotic treatment can resolve the symptoms of some rheumatoid-arthritis patients.
“There are definitely people who have what appears to be autoimmune disease, in whom the trigger is still present and active in the body,” he notes. “If you can treat the trigger, the autoimmune disease goes away.”
The uneven effects of vaccination on long-haulers point to a frustrating truth: The condition, its manifestations, and its underlying causes seem to vary greatly from person to person. “We have many more questions than answers at this point about how the vaccine might be helping,” says osteopath Leonard Calabrese, DO, director of the Cleveland Clinic’s R. J. Fasenmyer Center for Clinical Immunology.
(For more on autoimmune issues, see “Autoimmunity Now”.)