The Long-Term Immune Effects of COVID — A Warning We’ve Seen Before.

By Spela Salamon, Andrew G. Ewing, Yaneer Bar-Yam, Deborah Lupton, Resia Pretorius, Arneaux Kruger

World Health Network, New England Complex Systems Institute, Cambridge, MA

When COVID-19 first emerged, we focused on the acute illness — the cough, the fever, the weeks at home or in the hospital — and the many deaths. But nearly six years in, the greatest danger for most people may not lie in the initial acute infection. Instead, it is the long-term impact infection with the novel coronavirus has on the body that concerns experts the most, and affects our health and society in profound ways.

Much like the term “Long COVID”, the term “Airborne AIDS” was coined by Long COVID patients who felt that it reflected their individual experience. It began to spread online and even in some headlines, causing controversy and confusion. Our goal was to scrutinize this term, provide clarity and context, and examine the potential scientific basis for such a choice of terminology by individuals experiencing Long COVID symptoms.

In our recent peer-reviewed paper, we examined the growing evidence that SARS-CoV-2 — the virus that causes COVID-19 — can cause lasting dysfunction of the immune system. As a reminder, SARS stands for severe acute respiratory syndrome. The first SARS outbreak occurred in 2002-2004. What we learned from these first SARS cases caused by SARS-CoV-1 is that the impacts of this acute infection are long lasting, causing persistent illness and impairment in a high percentage of survivors. Since SARS-CoV-2 spread around the world beginning in 2020, medical science has shown similar unfortunate consequences. Drawing on studies from around the world, we identified patterns that should change how we think about this disease: not as a brief illness like a common cold to “get through,” but as something that can leave long-term effects even after symptoms subside and the test results turn negative.

This is not speculation. Researchers have documented that repeated COVID infections are associated with measurable disruptions to immune function. Some immune cells are depleted. Others become dysregulated — unable to do their jobs properly, or backfire on the body itself in the form of autoimmune diseases. Damaged blood vessel linings and mitochondria, impaired blood flow and disturbances of digestive system bacteria can all additionally weigh on the immune system with chronic inflammation, which leads to accelerated aging. These effects can persist for months or sometimes even years, or fail to resolve due to constant reinfections. Sometimes they are due to persistent viral infection or viral remnants, chipping away at our immune resources over time.

And we’ve seen this kind of story before.

HIV (human immunodeficiency virus), a very different virus, also causes long-term immune damage – though much more delayed, severe, and consistently deadly. One HIV infection leads to AIDS (acquired immunodeficiency syndrome): a progressive collapse of immune defenses over about a decade, if untreated. SARS-CoV-2 doesn’t behave the same way — but the patterns of increased vulnerability to infections, cognitive decline and accelerated aging are disturbingly familiar. This kind of immune and neurological disruption is one part of what’s known as Long COVID, a condition that can involve damage to multiple organs and worsens with reinfection.

This doesn’t mean COVID is the same as HIV-acquired AIDS, and we do not endorse the use of the term ‘Airborne AIDS,’ as is clearly stated in our review. COVID is “better “ in some ways, and “worse” in others. It spreads and works much faster to disrupt immunity, while its effects a decade on are still unknown. Unlike in untreated HIV infection, gradual recovery of immune function and/or Long COVID symptoms happen in some individuals without specific treatments, especially if reinfections are avoided. But the comparison helps us see something that public health discourse has largely avoided: we may be living through a slow-moving immune decline crisis. 

The signs are already visible.

The “cold and flu” seasons have been worse than ever since the abandonment of airborne protection measures. In people who have had COVID (a large percentage of the world’s population by now), we’re already seeing increased vulnerability to other diseases — shingles, fungal infections, reactivated viruses, and even opportunistic infections usually seen in people with weakened immune systems. 

These are not flukes, or results  of “missed infections” or “immune debt” — on the contrary. They are clear biological signals of reduced immune competence as a result of infections with an immune disrupting virus.

The term “Long COVID” has often been used as a catchall for lingering symptoms, but it’s time to acknowledge that many of those symptoms are not just leftovers — they’re signs of lasting damage and, in some cases, ongoing infection due to the virus persisting in the body’s tissues and organs. The immune system, the brain, the cardiovascular system — all can be affected. And this harm is not evenly distributed. Some people might recover fully. Others accumulate damage with each reinfection, and for many, it only becomes visible when other health problems appear.

The lesson from HIV is that viruses can have long-term consequences — and they can come back to bite you. AIDS was not just a medical crisis — it was a failure of attention and solidarity. Individuals living with chronic illness should not be stigmatized, dismissed and disbelieved. We can’t afford to make that mistake again. We need research into causal treatments based on disease biology, and above all, prevention. 

The healthy, recovered, recovering and not recovered from COVID all face the same highest risk for worsening — getting reinfected. And unlike for HIV infection, we have no approved specific treatments for the post-acute impacts of COVID or drugs to prevent viral transmission.

That’s why prevention is key. Just as condoms and sterile needles can stop HIV in its tracks before it spreads, precautions against airborne infection work as reliable protection against SARS-COV-2. Clean air, testing, science-based isolation, remote work and respirator-grade masks are not just short-term tools. They are investments in long-term health — for individuals and for society.