A growing number of American adults have weakened immune systems, which can leave them vulnerable to severe illnesses.
Kaley Karaffa had just turned 28 when the reality of having a weakened immune system as a cancer patient started to sink in. A few weeks earlier, at an annual medical exam, Ms. Karaffa had expressed concern to her doctor about enlarged lymph nodes near her collarbone. Testing showed that Ms. Karaffa had a type of B-cell lymphoma, a cancer that affects the white blood cells, which are essential to fighting off infections.
“I had to become cautious about who I saw, the activities I was involved in and even the kind of food I ate,” Ms. Karaffa, who is now 38, said.
Even a seemingly minor threat like the common cold can lead to a serious illness in someone with a compromised immune system.For Ms. Karaffa, getting sick would also mean having to pause the clinical trial she was participating in to receive cancer treatment.
The Covid-19 pandemic made many people familiar with the term “immunocompromised.” But while public health messaging around Covid, flu season or even food-borne illness outbreaks may make those who are immunocompromised sound like a homogenous group with the same kinds of conditions and a similarly high risk of illness, there is a broad spectrum of vulnerability.
And their numbers appear to be going up. A study published this year suggests that about 7 percent of U.S. adults — or about 18 million people — have immune systems that are suppressed in some way, up from about 3 percent in 2013. Researchers have different theories to explain the rise in immune suppression. Some believe it may be caused by an increase in autoimmune diseases, while others blame increasing rates of cancer and chronic diseases that require immunosuppressive treatment and the broader use of medications that can impact the immune system.
“It’s no longer a niche group,” said Dr. Joshua Hill, a specialist who treats infectious diseases in immunocompromised cancer patients at Fred Hutch Cancer Center in Seattle. “These are people walking around in the community that you might not know are immunocompromised,” he added.