The more you understand about primary immunodeficiency (PI), the better you can live with the disease or support others in your life with PI. Learn more about PI, including the various diagnoses and treatment options.
Living with primary immunodeficiency (PI) can be challenging, but you’re not alone—many people with PI lead full and active lives. With the right support and resources, you can, too.
Be a hero for those with PI. Change lives by promoting primary immunodeficiency (PI) awareness and taking action in your community through advocacy, donating, volunteering, or fundraising.
Whether you’re a clinician, researcher, or an individual with primary immunodeficiency (PI), IDF has resources to help you advance the field. Get details on surveys, grants, and clinical trials.
COVID-19, sometimes known as COVID or the coronavirus, is a contagious respiratory disease. Symptoms vary from person to person, with some people experiencing no or mild symptoms while others experience life-threatening disease. COVID-19 symptoms can include fever or chills, cough, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, stuffy or runny nose, nausea or vomiting, diarrhea, and shortness of breath.
When COVID-19 first infected people, it was considered an epidemic health emergency. COVID-19 has since become endemic, which means that it continues to spread widely at low levels around the world. In 2023, the U.S. Centers for Disease Control and Prevention (CDC) estimates that 75,000 people in the U.S. died from COVID-19 complications, which means that COVID-19 continues to be more deadly than the flu. Certain risk factors make people more likely to have a severe infection, but anyone can develop severe disease, even individuals who have had mild COVID-19 in the past.
Seek immediate medical attention if you have any of the following symptoms, which can indicate severe COVID-19:
People who have had COVID-19 can also develop two very different complications after their initial infection—multisystem inflammatory syndrome (MIS-C/MIS-A) or long COVID. Again, while there are factors that increase a person's risk, anyone, including children and those with mild COVID-19 symptoms, can develop these complications.
MIS-C/MIS-A is a very rare but life-threatening condition that develops up to eight weeks after the initial COVID-19 infection. Those with MIS-C/MIS-A have a fever above 100° F (38°C) for more than 24 hours with evidence of inflammation throughout their bodies, including:
Seek medical attention immediately if you have symptoms of MIS-C/MIS-A.
The National Academies of Sciences, Engineering and Medicine defines long COVID (also known as post-acute sequelae of COVID or PASC) as a chronic condition that lasts at least three months after the initial COVID-19 infection. Symptoms vary and can include shortness of breath, cough, persistent fatigue, fatigue after exercise or exertion, cognitive problems such as brain fog and memory changes, recurring headache, lightheadedness, rapid heartbeat, sleep disturbance, problems with taste or smell, bloating, constipation, and diarrhea.
COVID-19, colds, respiratory syncytial virus (RSV), and the flu have overlapping symptoms but are different respiratory illnesses with different treatments. Because symptoms alone can’t determine which illness someone has, it’s important to get tested if you feel sick. Note that it is possible to get multiple respiratory illnesses at the same time.
There is no definitive data on whether those with PI are more likely to get COVID-19 than others. However, there have been studies looking at PI and the course of COVID-19, including severe COVID-19, MIS-C/MIS-A, and long COVID.
Importantly, age, regardless of any other factor, is the single greatest risk factor for developing severe COVID-19. An analysis of adults hospitalized in 2020 that adjusted for chronic conditions found that:
PIs that disrupt the type I interferon response like TLR7 deficiency or autoimmune polyendocrinopathy syndrome type 1 (APS-1, also known as autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy or APECED) place individuals at very high risk for developing severe COVID-19. The interferon response is critical for controlling the virus early on and, without it, the virus spreads rapidly in the body.
The data for most other types of PI are less definitive. However, a large CDC study looking at healthcare records found that adults with PI and COVID-19 who went to the emergency room were hospitalized, were admitted to the ICU, were put on ventilators, and died at higher rates than those without PI. The increased risk ranged from 1.4 (ventilation or death) to 2.4 (hospitalization) times higher than those without PI.
In addition to PI, certain medical conditions, including some that tend to co-occur with or result from PI (bolded below), make it more likely that someone will develop severe COVID-19.
Medical treatments and behaviors can also be risk factors for severe COVID-19, including:
Risk factors are cumulative, which means that the risk of developing severe COVID-19 increases for every additional risk factor a person has. For example, a person who is 18 years old with an antibody deficiency (one risk factor) is less likely to become severely ill with COVID-19 than someone who is 65 years old with an antibody deficiency and bronchiectasis (three risk factors).
MIS-C affects approximately 1 in 10,000 children who have had COVID-19, but there are also rare reports of MIS in adults (MIS-A). Certain types of PI that include immune dysregulation are associated with developing MIS-C. Genetic studies of children with MIS-C have identified variants in the following PI-related genes:
There are no data on whether individuals with other types of PI, such as antibody deficiencies, are at increased risk for MIS-C/MIS-A.
Around 6% of adults and 1% of children develop long COVID according to estimates. There is little research on long COVID and PI, but one study of healthcare claims within a nonprofit health system in New England found that those with PI were about three times more likely to have a long COVID diagnosis compared to individuals without PI.
COVID-19 is caused by a coronavirus called SARS-CoV-2. The SARS-CoV-2 virus spreads primarily through the air when an infected person coughs, sneezes, talks, or exhales. Others then inhale or come in contact with viral particles. The viral particles enter the body through mucous membranes in the nose, mouth, and eyes.
To a lesser extent, COVID-19 can also be spread by touching contaminated surfaces and then touching your nose, mouth, or eyes.
People with COVID-19 are most contagious within the first five days of symptoms but can remain infectious up to 14 days or longer. Note that people who are immunocompromised, including those with PI, can have prolonged or persistent infections that last for a month or more. People who are infected with COVID-19 but have no symptoms are also contagious and can still spread it to others.
Visit the Center for Disease Control and Prevention's (CDC) website to find vaccines near you.
Protect yourselfA study conducted through the USIDNET patient registry demonstrated that vaccinated people with PI who had COVID-19 were significantly less likely to be hospitalized, be admitted to the ICU, or die than those with PI who were not vaccinated.
As with the flu vaccine, the Food and Drug Administration (FDA) recommends periodic updates to COVID-19 vaccines so that they match circulating SARS-CoV-2 strains. The current 2024-2025 COVID-19 vaccines target the KP.2 strain of SARS-CoV-2 and became available in September 2024.
The CDC recommends that everyone 6 months old and older receive at least one dose of the most current COVID-19 vaccine. See CDC’s page for those who are moderately to severely immunocompromised for the most up-to-date recommendations on whether to receive more than one dose.
Why should everyone be immunized? First, many people with PI develop at least some antibodies and a T cell response, which is important for controlling viral infections, to the vaccine. Those who are on immunoglobulin (Ig) replacement therapy (IVIG or SCIG) receive some protection from pooled COVID-19-neutralizing antibodies in their Ig. However, Ig manufacturing takes six months or more from the initial plasma donation. Vaccination can provide additional protection against newer strains, as well as an extra layer of protection.
Finally, household members of people with PI should get vaccinated to create a "protective cocoon" around the person with PI and decrease their exposure to the SARS-CoV-2 virus.
The FDA approved pemivibart, made by Invivyd and marketed under the trade name Pemgarda, in March 2024. Pemgarda is a monoclonal antibody, which means that unlike vaccines, it provides protection regardless of how well a person’s immune system works. It is meant to be used before exposure to prevent COVID-19 in those who are at least 12 years of age, weigh at least 88 pounds, and are moderately to severely immunocompromised. It is not approved for use after exposure or infection.
Pemgarda is given as an intravenous infusion every three months and must be prescribed by a healthcare provider. Infectious Disease Society of America’s clinical guidelines for Pemgarda can help healthcare providers determine if their patients should receive it. It is typically given at an infusion center or other healthcare facility; see Invivyd’s facility locator for locations that offer Pemgarda.
Respiratory viruses like COVID-19 spread through the air, so crowded, indoor spaces with poor airflow increase the possibility of a sick person infecting others. The Environmental Protection Agency (EPA) recommends improving indoor ventilation as a way to protect against COVID-19 spread.
Simple actions you can take include:
There are several strategies centered around avoiding contact with viral particles that can help you stay well:
The health and safety of all participants is of paramount importance to IDF as we return to in-person events.
People with PI should discuss plans with their healthcare provider for dealing with COVID-19, including:
In case of illness, those with PI should immediately test for COVID-19 using an unexpired, rapid antigen test at home. Keep in mind that rapid antigen tests may be negative early in an infection even if you really do have COVID-19. If the rapid test is negative, consider getting a more sensitive PCR test (sometimes called a NAAT test) and testing for other respiratory viruses. These tests are typically available at pharmacies, urgent care centers, and healthcare provider offices.
If you test positive for COVID-19 by either a rapid antigen test or a PCR test, contact your healthcare provider to get and start antiviral treatment as soon as possible. COVID-19 antivirals are most effective within 5-7 days of symptoms appearing.
Note that many people delay COVID-19 antiviral treatment because they don’t feel ‘that bad’ initially, but mild symptoms can rapidly become serious. Don’t wait!
There are several antivirals available to treat COVID-19:
A pill that is taken twice daily for five days and must be started within five days of symptoms. Paxlovid is FDA-authorized for those 12-17 years of age and FDA-approved for those 18 years old and older. Use the FDA’s checklist with your healthcare provider to determine if you can safely take Paxlovid.
A pill that is taken twice daily for five days and must be started within five days of symptoms. Lagevrio is FDA-authorized for those 18 years old and older who cannot safely take Paxlovid.
Remdesivir is given intravenously over three days and must be started within seven days of symptoms. It is FDA-approved for those 28 days old or older who weigh at least 3 kg.
Learn about this year’s vaccines, influenza symptoms and treatments, and how to prepare if someone in your family has primary immunodeficiency.
Since COVID-19 emerged, IDF has advocated for policy and regulatory changes that support, uplift, and protect people with PI through the Immunocompromised Collaborative.
This page contains general medical and/or legal information that cannot be applied safely to any individual case. Medical and/or legal knowledge and practice can change rapidly. Therefore, this page should not be used as a substitute for professional medical and/or legal advice. Additionally, links to other resources and websites are shared for informational purposes only and should not be considered an endorsement by the Immune Deficiency Foundation.
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