What is Immunoglobulin Therapy?
Intravenous immunoglobulin (IVIG) is a therapy that delivers concentrated antibodies (proteins produced by the immune system that help recognize and neutralize pathogens like viruses and bacteria) from healthy donors into the bloodstream. It’s commonly used to treat autoimmune and immune-deficient conditions. Recently, researchers have begun investigating IVIG as a potential treatment for Long COVID, particularly in patients experiencing neurological or cardiovascular symptoms. It differs from monoclonal antibody (mAb) therapy in that it does not target lingering SARS-CoV-2 spike protein, but rather modulates and calms the immune system so that it doesn’t harm the body.
How IVIG Might Help with Long COVID
- Immune Modulation – IVIG can neutralize harmful autoantibodies, reduce excessive inflammation, and regulate immune system activity—all of which are suspected contributors to Long COVID.
- Nerve Repair and Protection – In patients with small fiber neuropathy or dysautonomia, IVIG may help reduce nerve-related symptoms by calming immune-driven nerve damage.
What the Research Says
Early research and case reports suggest that IVIG may help some people with Long COVID. Studies have shown improvements in vascular health, cognitive function, pain, and overall quality of life. While more large trials are needed, current results are encouraging for selected patients under specialist care.
Key literature on Intravenous Immunoglobulins
Clinical trials and case reports showing positive effects:
- This prospective study evaluated 21 Long COVID patients treated with monthly IVIG for 3 months, compared to 29 patients receiving only supportive care. IVIG-treated patients showed a 27% increase in vascular function, significant improvements in neurocognitive performance, reduced fatigue and disability, and improved quality of life.
- This case series followed 9 Long COVID patients with neurological and cardiac symptoms treated with high-dose IVIG. Of the six who received treatment, all reported significant or remarkable clinical improvement. These patients had been symptomatic for between 101 and 547 days prior to starting IVIG.
- This review focused on small fiber neuropathy (SFN), a condition linked to Long COVID symptoms like POTS and chronic pain. A retrospective study of 9 SFN patients treated with IVIG showed either complete or substantial symptom relief, even when started over a year after infection. The article emphasizes the need for controlled trials.
Articles discussing theoretical benefits:
- This hypothesis paper proposed that IVIG could benefit Long COVID patients by suppressing autoantibodies, modulating immune responses, and reducing inflammation. While theoretical, it supports the growing interest in IVIG as a therapeutic option.
Final Thoughts
Early studies and case reports suggest IVIG may be a helpful treatment for Long COVID, especially in patients with immune dysfunction, small fiber neuropathy, or persistent neurological symptoms. Clinical improvements in fatigue, cognition, and vascular health have been reported, but larger controlled trials are needed to confirm these effects and determine ideal dosing. As a prescription therapy, IVIG therapy can only be performed under the supervision of a medical professional.