This observational study is being conducted by Healing Hope International to collect real-world data on an emerging treatment approach for Long COVID in patients with immunodeficiency. The study investigates the effects of intranasal immunoglobulin (IVIG) therapy in a real-world setting.

Participants will be individuals diagnosed with Long COVID who have confirmed immunodeficiency, such as low IgG or IgA levels or specific antibody deficiency. These individuals are receiving care through international clinical programs and will not receive any treatment as part of this study. Instead, Healing Hope will collect health information, clinical outcomes, and laboratory results from participating sites to better understand how intranasal IVIG might help reduce symptoms such as fatigue, brain fog, inflammation, and immune dysregulation.

The goal of this study is to contribute new insights into potential treatment options for Long COVID and to support responsible, science-backed care models for patients participating in medical tourism. No experimental drugs are being administered as part of this protocol. All treatment decisions are made independently by each clinical site. Data will be anonymized and used to advance knowledge in the field of immunological recovery and neuroinflammation.

This observational study, initiated by Healing Hope International, is designed to collect real-world data (RWD) from individuals diagnosed with Long COVID who are undergoing clinical care involving intranasal immunoglobulin (IVIG) therapy at international medical tourism sites.

Eligible participants are adults (ages 18-65) with:

Persistent Long COVID symptoms for ≥12 weeks following SARS-CoV-2 infection,

Laboratory-confirmed immunodeficiency (e.g., low IgG/IgA, poor vaccine response, or specific antibody deficiency),

Elevated inflammatory biomarkers (e.g., CRP, cytokines),

No evidence of active infection (bacterial, viral, or fungal),

No comorbid neurological conditions (e.g., multiple sclerosis, Alzheimer's disease),

No current immunosuppressive therapies.

No investigational product will be administered by the study team. All treatments are prescribed and delivered independently by licensed international clinical sites. Healing Hope International operates as the sponsor and data coordinating center. Participants' data will be collected retrospectively and prospectively from site medical records, patient-reported surveys, and third-party laboratory assessments, including genetic testing for RXRA expression (e.g., via qPCR or NGS panels).

The primary data endpoints include:

Changes in immunological biomarkers (IgG/IgA, CRP, cytokine panel),

Clinical course of Long COVID symptoms (fatigue, cognitive impairment, respiratory issues),

Quality of life measures (collected via validated patient-reported outcome instruments).

The study complies with all applicable regulations for data protection and ethical research conduct, including informed consent, HIPAA-compliant data transfer where applicable, and de-identification of personal health information. Ethical approval will be obtained from an Institutional Review Board (IRB), and partner sites may obtain parallel local or national ethics approvals.

This study also seeks to characterize the broader landscape of medical tourism for regenerative therapies by mapping treatment accessibility, safety, and patient reported effectiveness in the context of international care. It does not replace or compete with regulated clinical trials but aims to generate actionable real world insights that can guide future controlled research.

By contributing to the body of evidence around global regenerative practices, this study supports the development of international ethical guidelines, compassionate use frameworks, and collaborative trial infrastructure in complex chronic conditions.

Inclusion Criteria:

• Age 18 to 65 years
• Clinical diagnosis of Long COVID (symptoms persisting ≥12 weeks after SARS-CoV-2 infection)
• Laboratory-confirmed immunodeficiency, including one or more of the following:
• Low serum IgG and/or IgA
• Specific antibody deficiency
• Low pneumonia titers
• Elevated inflammatory markers (e.g., CRP, cytokines)
• No active infections at the time of enrollment (bacterial, viral, or fungal)
• Negative for Lyme disease and NMDAR antibodies
• Willingness to provide informed consent for data collection and use

Exclusion Criteria:

• Current or recent active infection (e.g., viral, bacterial, or fungal)
• Use of immunosuppressive therapy within the last 3 months
• Active infections: Participants with active infections, including viral, bacterial, or fungal infections, will be excluded
• Neurological disorders: Participants with diagnosed neurological disorders (e.g., multiple sclerosis, Parkinson's disease, Alzheimer's disease) will be excluded
• Immunosuppressive therapy: Participants receiving immunosuppressive therapy will be excluded
• Inability to comply with study assessments or procedures

This study enrolls adults aged 18 to 65 with persistent Long COVID symptoms and confirmed immunodeficiency, including low IgG/IgA or poor vaccine response. Participants must have elevated inflammatory markers and be free of active infections or neurological conditions. The population is observed while undergoing intranasal IVIG therapy internationally, with a focus on immunological, genetic, and quality of life outcomes.

Healing Hope International is currently evaluating options for secure and ethical data sharing in accordance with international data protection standards and participant consent. If IPD sharing becomes feasible, de-identified data may be made available to qualified researchers upon request and IRB approval. A final determination will be made after assessing data governance infrastructure and stakeholder input.