COVID-19 and immunodeficiency

By Dr. Ananya Mandal, MDApr 21 2020

COVID-19 disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a highly infectious disease. As of today, over 170,000 people worldwide have succumbed to the infection. Reports have shown that some comorbidities and illnesses raise the risk of getting infected and also influence the severity of the disease. Having a compromised immune system can also drastically raise the risk of getting COVID-19.

What is immunodeficiency?

An immunocompromised person is one who has a less than complete, defective, or incomplete immune system protection against infection. Not just COVID-19, these individuals are more at risk of several infections, including bacterial, fungal, and viral.

Immunodeficiency refers to two types – primary and secondary. Primary immunodeficiency is caused when someone is born with the condition that does not allow their immune system to develop fully. These include conditions such as Common Variable Immunodeficiency, Severe Combined Immunodeficiency (SCID), X linked Agammaglobulinemia.

Illustration of coronavirus infecting respiratory system. Image Credit: Iokanan VFX Studios / Shutterstock

Secondary immunodeficiencies include diseases that can lead to the suppression of immunity. These include diseases or infections such as AIDs (infection with HIV), certain toxic drugs or poisons such as air pollutants, pesticides, heavy metals, cigarette smoking, etc. Immunodeficiency can also occur among alcoholics, the elderly, those with malnutrition, and also pregnant women. Among pregnant women, the immune system is generally suppressed. Newborn babies are generally immunodeficient. With time their immune system develops. Babies that are breastfed receive antibodies from their mother’s milk that helps them to fight off infections.

Cancers such as leukemias, lymphomas, and others can also suppress immunity to a significant degree. Cancer patients who have been treated with chemotherapy and radiation therapy also have significantly suppressed immunity as these drugs and therapies can suppress the bone marrow that is the site of production of immune cells in the body. Those who have had organ transplants often have to have drugs that suppress immunity and steroids. These patients are at risk of rejecting the donated organ, and their immune system needs to be suppressed by external drugs so that organ rejection does not take place.

What happens if an immunocompromised patient is exposed to SARS CoV-2 infection?

Persons who have a defective immune system when exposed to the SARS-CoV-2 virus, are unable to fight off the infection and thus are more at risk of getting the infection and their disease turning more severe.

Researchers say that both a low immunity and overactive immunity can be dangerous for those with COVID-19. While a suppressed immunity can make an individual more susceptible to infection, an overactive immunity is often the reason behind the cytokine storm or the immunological overdrive that leads to severe symptoms in the patients.

Researchers have not yet found confirmatory evidence regarding the exact effects of immunosuppression on patients with COVID-19. At present several studies are looking at the potential beneficial or harmful effects of steroids (known immunosuppressants) on the clinical course of COVID-19.

CDC outlines who is at risk

According to the webpage of the Centre for Disease Control and Prevention (CDC), those at high risk of COVID 19 are those who are 65 years or older and those living in nursing or other care facilities. Persons with the following conditions are also at higher risk of severe COVID-19, the CDC says, especially if the disease is not well controlled. These diseases include;

• Moderate to severe asthma or chronic lung diseases
• Serious heart conditions
• Immunocompromised patients. The CDC defines immunocompromised patients as those on “cancer treatment, smoking, bone marrow or organ transplantation, immune deficiencies, poorly controlled HIV or AIDS, and prolonged use of corticosteroids and other immune weakening medications.”
• Severely obese individuals with a Body Mass Index of over 40
• Uncontrolled diabetes
• Uncontrolled chronic kidney disease and those undergoing diabetes
• Liver disease

CDC recommendations

For all patients who are at risk of severe COVID-19 disease, the CDC outlines some to-dos. These include;

• Continuation of medications as recommended by the treating physician.
• Keep at the ready, at least two weeks worth supply of medicine
• Keeping up to date with vaccinations that have been recommended. For the elderly, for example, vaccines against influenza and pneumococcal pneumonia have been recommended.
• Seek emergency treatment in case of any symptom or exacerbation of an underlying condition

For those with moderate to severe asthma, the treatment plan must be strictly followed to keep asthma under control. Knowing the correct way of inhalation and avoiding asthma triggers is also important. The same is true for those with other chronic lung diseases.

Persons with type 1 or type 2 diabetes are also advised to keep their disease under control by regularly taking medications and monitoring their blood sugar levels. Persons with heart failure, coronary artery disease, hypertension, cardiomyopathies, congenital heart diseases, or pulmonary hypertension also need to be careful about COVID-19 infection. If they have been prescribed angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin-II receptor blockers (ARB), these must be continued, says the CDC. Blood pressure should be routinely monitored. Those with chronic kidney disease and those on dialysis need to follow their treatment schedule and dialysis strictly. Diet in times of lockdown should be kept in mid says the CDC and supplies should be ensured to maintain nutrition. Those who are immunocompromised and those with liver disease, too, need to be careful and adhere to their treatment plans.

For all the vulnerable groups of patients, including the elderly and those in nursing care facilities, it is recommended that they practice isolation and hygiene and protect themselves from getting infected.