When your body can’t make enough antibodies, even a simple cold can turn into something serious. That’s the reality for people with common variable immunodeficiency (CVID), a condition where the immune system fails to produce the protective proteins needed to fight off infections. Unlike a temporary weakness after the flu, CVID is lifelong. It doesn’t go away with rest or vitamins. And for many, it takes years just to get a correct diagnosis.
What Exactly Is CVID?
CVID is a primary immunodeficiency - meaning it’s caused by a flaw in the immune system from birth, even if symptoms don’t show up until adulthood. It’s not caused by HIV, chemotherapy, or aging. It’s genetic. But here’s the twist: no single gene is to blame. More than 20 different gene changes have been linked to CVID, and in most cases, doctors still can’t pinpoint exactly which one is causing the problem.
What we do know is this: your B cells - the white blood cells that make antibodies - are present, but they’re stuck. They can’t mature properly. As a result, your body produces very little IgG, the main antibody that protects against bacteria. IgA, which guards your lungs and gut, is often nearly gone. IgM, another key player, is low in about half of cases. Without these, your body can’t recognize or kill common invaders like Streptococcus pneumoniae or Haemophilus influenzae.
That’s why people with CVID get sick so often. While most adults get 2 to 4 respiratory infections a year, CVID patients average 7 to 12. Some get pneumonia every few months. Others develop chronic sinus infections that never fully clear. It’s not just about being sick more - it’s about being sick longer, and with more complications.
Why Diagnosis Takes So Long
On average, it takes 8.2 years from when symptoms first appear to get a CVID diagnosis. Why? Because the symptoms look like everything else. Repeated ear infections? Kids get those. Chronic bronchitis? Smokers get that. Fatigue and weight loss? Stress or thyroid issues. Doctors often treat the symptoms, not the root cause.
By the time someone sees an immunologist, they’ve usually been to three or more specialists. Blood tests are the key. A simple serum immunoglobulin panel can show if IgG is below 500 mg/dL (normal is 700-1600), IgA is below 7 mg/dL (normal is 70-400), and IgM is under 40 mg/dL. But that’s not enough. Doctors also test how well your body responds to vaccines. If you’ve had a pneumococcal shot and your antibody levels don’t rise, that’s a red flag.
Even then, it’s not always clear-cut. Some people have low antibodies but never get sick. Others have normal levels but still get frequent infections. That’s why experts now say the current diagnostic criteria might be too broad - lumping together several different diseases under one name. More precise subtyping is coming, but for now, diagnosis still relies on clinical patterns and lab results.
What Happens When Antibodies Are Missing
Low antibodies don’t just mean more colds. They open the door to serious, long-term damage.
- Lungs: About 65% of CVID patients develop chronic lung disease by age 50. Repeated infections scar the airways, leading to bronchiectasis - where lungs become widened and floppy, trapping mucus and bacteria. This is irreversible and often requires daily breathing treatments.
- Gut: Up to half of patients have digestive problems. Diarrhea, bloating, weight loss - sometimes caused by Giardia, a parasite that thrives when IgA is gone. Others develop inflammation similar to Crohn’s disease, even though they don’t have the typical genetic markers.
- Autoimmunity: One in four CVID patients develops an autoimmune disorder. Immune thrombocytopenia (ITP) destroys platelets, causing easy bruising. Autoimmune hemolytic anemia attacks red blood cells. Rheumatoid-like arthritis can appear without any family history.
- Cancer: The risk of lymphoma is 20 to 50 times higher than in the general population. That’s why regular screenings - chest CTs, endoscopies, blood tests - are part of long-term care.
It’s not just infections that kill. It’s what they leave behind.
How CVID Is Treated Today
There’s no cure. But there is life-changing treatment: immunoglobulin replacement therapy.
This means giving patients purified antibodies collected from thousands of healthy donors. It’s not a drug you take orally. It’s infused - either into a vein (IVIG) or under the skin (SCIG). Both work. Neither cures CVID. But both keep people alive.
Standard dosing is 400-600 mg per kilogram of body weight every 3-4 weeks for IVIG. For SCIG, it’s 100-150 mg per kilogram weekly. The goal? Keep IgG levels above 800 mg/dL. That’s the threshold most doctors agree on to prevent infections.
People on therapy report huge improvements. One 2023 survey found that infection rates dropped from over 10 per year to just 2.1. Energy levels improved in 78% of patients within three months. Many go back to work, travel, play with their kids - things they couldn’t do before.
But it’s not perfect. IVIG infusions can cause headaches, chills, or nausea in 32% of patients. SCIG is often better tolerated, but 25-40% get redness or swelling at the injection site. That’s why many learn to do it at home. After 3-5 supervised sessions, most patients manage it themselves. The learning curve is steep, but the freedom is worth it.
The Cost and the Crisis
Immunoglobulin therapy is expensive. In the U.S., IVIG costs $65,000-$95,000 a year. SCIG runs $70,000-$100,000. Insurance usually covers it, but co-pays can still be thousands. In low- and middle-income countries, only 35% of diagnosed patients get treatment - because the supply simply isn’t there.
Why? Because immunoglobulin comes from human plasma. And we’re running out. The global plasma supply is 12% short of demand. That’s pushing prices up 15-20% each year. Some patients are already seeing delays in shipments. Hospitals are rationing doses.
And there’s no easy fix. Plasma collection relies on donors - mostly in the U.S. and Europe. There are no synthetic alternatives yet. Recombinant antibodies are in trials, but they’re still years away. For now, we’re stuck depending on a fragile, human-sourced supply chain.
What’s Next for CVID Treatment
Researchers are working on better options. One promising drug, atacicept, targets two proteins (BAFF and APRIL) that mess up B cell development. In early trials, it cut severe infections by 37% compared to standard therapy alone. It’s not a replacement for immunoglobulin - but it could be an add-on for patients who still get sick despite treatment.
Genetic testing is also getting smarter. Scientists now believe CVID isn’t one disease - it’s a group of related disorders. Some patients might respond to biologics that target specific pathways. Others may need stem cell transplants. The goal? Move from blanket antibody replacement to personalized medicine.
For now, though, the best thing you can do is get diagnosed early and stay on therapy. Life expectancy for CVID patients has jumped from 33 years in the 1970s to nearly 59 today - thanks to consistent immunoglobulin treatment. That’s not a miracle. It’s science.
Living With CVID
It’s not just about medicine. It’s about lifestyle. People with CVID need to avoid crowds during flu season. They should get annual flu and pneumococcal shots (though their response may be weak). They need to wash hands constantly. They should avoid raw milk, undercooked meat, and untreated water - anything that could carry bacteria or parasites.
Support matters too. The Immune Deficiency Foundation has over 200 local groups and 15,000 members. Their annual conference brings together patients, families, and doctors. Talking to others who get it - who know what it’s like to miss work because of another infection, or to feel exhausted even when you’re not sick - makes a huge difference.
There’s no cure yet. But with treatment, many people with CVID live full, active lives. They’re teachers, parents, artists, runners. They’re not defined by their diagnosis. They’re defined by how they manage it.
Can CVID be cured?
No, there is currently no cure for CVID. It is a lifelong condition caused by genetic defects in B cell function. However, immunoglobulin replacement therapy can effectively manage symptoms, prevent infections, and significantly improve quality of life and life expectancy.
How is CVID different from regular allergies?
CVID is not an allergy. Allergies happen when the immune system overreacts to harmless substances like pollen or peanuts. CVID is the opposite - the immune system underreacts. It can’t make enough antibodies to fight real threats like bacteria and viruses. People with CVID don’t have allergic reactions to foods or dust - they get repeated, severe infections.
Is CVID hereditary?
CVID is often genetic, but it doesn’t follow a simple inheritance pattern. In most cases, no single gene mutation is found, and family members may not show symptoms. However, about 10-25% of patients have a family history of immunodeficiency or autoimmune disease, suggesting a genetic link. Genetic testing can help identify risk in some families.
Can you outgrow CVID?
No, CVID is a lifelong condition. Symptoms usually appear between ages 20 and 40, but the underlying immune defect is present from birth. Unlike some childhood immunodeficiencies that improve with age, CVID does not resolve on its own. Lifelong immunoglobulin therapy is typically required.
What happens if you stop immunoglobulin therapy?
Stopping immunoglobulin therapy leads to a rapid drop in antibody levels, usually within weeks. Infections return quickly - often more severe than before. Chronic lung damage, autoimmune complications, and cancer risk increase significantly. Therapy must be continuous; skipping doses or stopping treatment can be life-threatening.
Are there side effects from immunoglobulin therapy?
Yes, side effects can occur. With IVIG, common reactions include headaches, chills, nausea, and fatigue. About 32% of patients experience these. SCIG causes fewer systemic reactions but can lead to redness, swelling, or itching at the injection site in 25-40% of users. Most side effects are mild and manageable with dose adjustments or pre-medication.
How do you know if your treatment is working?
The best signs are fewer infections, less need for antibiotics, improved energy levels, and stable weight. Doctors also monitor trough IgG levels - keeping them above 800 mg/dL is the target. Regular lung scans and blood tests help catch complications early. If infections keep happening despite therapy, your dose may need adjustment or further testing for other immune problems.
What to Do Next
If you’ve had frequent, severe infections since childhood or early adulthood - especially if antibiotics don’t seem to help - talk to your doctor about seeing an immunologist. Don’t wait. Early diagnosis means early treatment, which means fewer complications down the road.
If you already have CVID, stay on your therapy. Keep your IgG levels checked. Join a support group. Learn how to manage your care at home. You’re not alone - and with the right care, you can live well.
