When the COVID-19 pandemic began, many people wondered how it would impact them, especially if living with a rare disease or condition. As the pandemic has progressed, more research has been done on COVID-19, as well as its relation to other conditions. According to News Medical, a more recent study centered around COVID-19 outcomes in those living with common variable immunodeficiency (CVID). 

The Study: An Overview

The Danish nationwide cohort study, published in Frontiers in Immunology, wanted to understand how COVID-19 impacted the general public (those without CVID) as opposed to how it impacted those living with CVID. To begin, the research team sourced data from the Danish Civil Registration System, the Danish National Patient Register, the Danish Vaccination Register, and the COVID-19 surveillance system. Next, the research team matched patients with CVID with eight control individuals for a total of 313 patients and 2,504 controls. Findings from the study show:

• The time it took for each group to be infected with COVID-19 was slightly different, though not highly concerning or different. Those with CVID were also slightly more likely to be reinfected. 
• Individuals with CVID typically tested for COVID-19 earlier and more frequently than the control group. The control group did see higher testing between March 2021 and August 2021. 
• Despite hospitalization, few people from either cohort needed mechanical ventilation support.
• After COVID-19 infection, people with CVID were at a higher risk of requiring hospitalization. Of the 313 patients, 45 (14.4%) went to the hospital but only 4 (1.3%) required hospitalization. 
• Those who had received three vaccinations had a lower risk of COVID-19 infection than those with two vaccinations, though three vaccinations also correlated with a slightly higher risk of hospital encounters.
• There were no significant differences between mortality rates for those with CVID and those without. 

Ultimately, the research study found that those with CVID had relatively straightforward experiences with COVID-19 during the pandemic compared to other groups. 

What is Common Variable Immunodeficiency (CVID)? 

Common variable immunodeficiency (CVID) is a primary immune deficiency disease characterized by antibody deficiency that makes someone more susceptible to bacterial and viral infections. Most commonly, these infections affect the lungs, ears, and sinuses. In a majority of cases, the cause is unknown, though many medical professionals believe that CVID results from a combination of environmental and genetic factors. However, around 10% of cases have a known cause; 13 different genes have been linked to CVID development. One such gene is TNFRSF13B. Regardless, this condition causes a shortage of immunoglobulin A and G. Around 25% of people with CVID also have an autoimmune disorder. 

Because there are so many different causes and forms, CVID is an extremely variable disease. It may differ in severity and symptoms even in people with the same form. Potential symptoms can include:

• Recurrent lung, sinus, or ear infections
• Pneumonia
• Gastrointestinal tract inflammation
• Unintended weight loss
• Diarrhea
• Increased risk of cancer
• Granuloma formation in various organs
• Swollen spleen or lymph nodes
• Chronic lung disease