CVID is one of the most common serious primary immunodeficiencies — and one of the most frequently overlooked. People with CVID do not produce enough functional antibodies, leaving them vulnerable to repeated and prolonged infections, often for years before diagnosis.
Common Variable Immunodeficiency — CVID — is a primary immune deficiency in which the body cannot produce enough effective antibodies to fight infection. Patients with CVID typically experience repeated sinus, ear, and lung infections, often requiring multiple courses of antibiotics and sometimes hospitalization. Many patients have lived with CVID for years before being diagnosed, having been treated repeatedly for "frequent infections" without anyone identifying the underlying cause.
CVID is one of the most common serious primary immunodeficiencies. While the name includes the word "common," that is relative — CVID is still considered a rare disease, which is part of why it is so often missed. Beyond infections, CVID can also involve autoimmune complications, gastrointestinal symptoms, and an increased risk of certain cancers, which makes early diagnosis and ongoing specialist care essential.
An evaluation for CVID may be appropriate if you have experienced any of the following:
Diagnosing CVID requires a complete immune workup. At Optimed Immunology, this typically includes quantitative immunoglobulins (IgG, IgA, IgM, IgE), IgG subclasses, specific antibody response testing to common vaccine antigens (pneumococcal, tetanus, diphtheria), and lymphocyte subset analysis. When a patient has not previously been vaccinated for relevant antigens, pre- and post-vaccination response testing is performed to assess whether the immune system can mount a protective response.
Other causes of low antibody levels — including certain medications, blood cancers, kidney disease, and protein loss — must be ruled out before a definitive CVID diagnosis is made. This is the kind of careful workup that takes time and clinical judgment, and it is the reason patients often need a specialist's evaluation rather than a single round of standard labs.
The standard of care for CVID is immunoglobulin replacement therapy — pooled human immunoglobulin (IgG) administered to restore the antibody-fighting capacity the immune system cannot produce on its own. Treatment is given either by intravenous infusion (IVIG) every 3 to 4 weeks, or by subcutaneous injection (SCIG) typically weekly. Both routes are effective. The choice depends on disease severity, vascular access, lifestyle, and patient preference.
Optimed Immunology coordinates infusion through trusted home infusion partners or in-suite at Horizon Infusions, which is co-located with the practice. Beyond immunoglobulin therapy, ongoing care includes vaccination management, antibiotic prophylaxis when indicated, and regular surveillance for CVID-associated complications. The practice handles all prior authorizations directly — patients are not asked to navigate insurance approvals on their own.
A first visit for suspected CVID typically lasts 45 to 60 minutes. Dr. McNeil takes a detailed history of your infection patterns, prior antibiotic and steroid courses, hospitalizations, and family history of immune-related disease. After examination, the rationale for each test ordered is discussed, and a clear plan is provided in writing. Lab results are reviewed by Dr. McNeil personally, and follow-up may be in person, by phone, or through the patient portal.
If a CVID diagnosis is confirmed, treatment can typically begin within several weeks once prior authorization is complete. Many patients describe a meaningful improvement in infection frequency and overall energy within the first few months of therapy. Individual response varies.
Decision support
Choosing between IV, subcutaneous, and facilitated-subcutaneous immunoglobulin? See the full comparison: IVIG vs SCIG vs fSCIG →
Every patient’s situation is different, but the decision logic for CVID generally follows these steps. This is not a script — it is a structure that gets adapted to each patient’s history, findings, and goals.
Donald L. McNeil, MD · Board Certified in Allergy & Immunology and Internal Medicine
This page is provided for educational purposes and does not substitute for clinical judgment or direct medical advice. Treatment decisions are individualized based on your full history, examination, and laboratory findings. If you have an emergency, call 911.