The COVID-19 pandemic may be over, but our immune systems are still feeling the impact. After years of battling constant viral threats, from COVID-19 to seasonal flu and other infections, our body’s defense system is exhausted. Many people continue to experience lingering inflammation, frequent illnesses, and slower recovery times. This extended state of immune stress has compromised us further to chronic illness, including autoimmune diseases and even neurodegenerative diseases such as Parkinson's. So why is our immune system still in trouble? And how do we give it its power back? Understanding immune exhaustion is the beginning of rebuilding our body's natural immunity.

A weakened immune system makes people more susceptible to disease, mental illnesses, and even sleep disorders. Now, new research indicates that immune system depletion may play an important role in the onset of Parkinson's disease, a degenerative neurologic disorder that compromises movement and cognition.

Role of Inflammation in Parkinson's Disease

Dysfunctional immune response is a leading cause of long-standing inflammation within the body, that has been found to contribute towards a multitude of conditions, including cardiovascular conditions, diabetes, depression, and neurodegenerative diseases such as Alzheimer's.

As people age, their immune system naturally becomes less effective. This deterioration, referred to as immune exhaustion, may be a key contributor to the onset and progression of Parkinson’s disease. Rebecca Wallings, a Parkinson’s Foundation Launch Award grant recipient and senior postdoctoral fellow at the University of Florida, believes that an accumulation of exhausted immune cells could be driving neurodegeneration in Parkinson’s patients.

How a Tired Immune System Might Affect Parkinson's?

Parkinson's disease is most commonly linked with the degeneration and loss of dopaminergic neurons—motor nerve cells that produce dopamine, an essential neurotransmitter for movement. While researchers have long suspected inflammation is involved in this neurodegeneration, the mechanisms are not yet well understood.

Wallings' study is on immune cell exhaustion, a process by which aging immune cells fail to control immune responses effectively. Her research indicates that instead of dampening inflammation in Parkinson's patients, attempts should be made to rejuvenate the immune system to regain its functionality.

Energy Deficiency in Immune Cells

One of the major findings of Wallings' work is the function of mitochondrial impairment in immune cell exhaustion. Mitochondria are commonly called the powerhouses of cells, as they are vital for generating energy. As mitochondria age and become inefficient, immune cells fail to function well, potentially accelerating neurodegeneration in Parkinson's disease.

Wallings has found that mutations in the LRRK2 gene, a recognized genetic risk factor for Parkinson's disease, are linked with defective mitochondrial function and immune cell exhaustion. Her current work includes testing various therapeutic approaches to restore mitochondrial function in immune cells with the potential to enhance the immune system and potentially prevent or treat Parkinson's disease.

Will Rejuvenating the Immune System Help in Treatment?

For decades, the standard practice in treating Parkinson's has been to suppress brain inflammation. Yet Wallings' work indicates that instead of slowing down immune responses, restoring the immune system could be a more successful strategy. By addressing mitochondrial impairment and immune resilience, researchers can potentially reverse or slow down Parkinson's disease.

Wallings is now looking into how to rejuvenate immune cells by fixing mitochondria. She studies immune cells from patients with Parkinson's as well as from healthy subjects and performs experiments on animal models to determine if rejuvenation of the immune system could result in improved disease outcomes.

Lifestyle Factors That May Affect Parkinson's Risk

While there is no cure for Parkinson's disease, some lifestyle adjustments may decrease the chances of developing the illness. Since neurodegenerative diseases are associated with chronic inflammation and immune dysfunction, developing habits that enhance immune function might prove helpful.

Diet: There is evidence to suggest that eating in accordance with the Mediterranean or MIND diets, both high in antioxidants, healthy fats, and anti-inflammatory foods, can encourage brain wellness and reduce Parkinson's risk.

Avoiding Dangerous Substances: Restricting alcohol and nicotine use can maintain a robust immune system and suppress inflammation.

Reducing Stress: Chronic stress weakens immune function, so methods such as meditation, exercise, and sufficient sleep can lead to improved overall well-being.

Doctors in India’s southern state of Tamil Nadu surgically removed a fully developed canine tooth from the upper eyelid region of a 16-year-old boy. They described the case as the first reported instance of an ectopic tooth in the upper part of the eye socket.

The case was reported by specialists at Aravind Eye Hospital in Madurai in the journal Ophthalmology.

What Did The Doctors Find?

The teenager visited the hospital with painless swelling of his left upper eyelid that had lasted a month. He had no history of injury to the area.

During the examination, doctors noticed two firm, whitish projections beneath the swollen area near the inner side of the upper eyelid, the experts shared in the paper.

A computed tomography (CT) scan revealed a dense structure resembling a tooth, with a crown and root, originating from the roof of the left eye socket. It extended towards the tissues in front of the orbital septum, a thin barrier separating the eyelid from the deeper eye socket, and protruded outwards with two tooth-like points on its surface.

The projections' appearance and texture raised the possibility that they were teeth. Dr. Meghana Tanwar, a medical consultant at Aravind Eye Hospital, told Live Science that they had a “fairly smooth surface and were hard on palpation.”

The doctors surgically removed the structure. Examination confirmed that it was a mature canine tooth without teratomatous elements, consistent with an ectopic tooth in the upper part of the eye socket.

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What Is An Ectopic Tooth?

An ectopic tooth develops or emerges in an abnormal location. Some remain within the mouth but appear outside their usual positions in the dental arch, while others develop outside the normal arrangement of teeth.

The latter is particularly unusual. In this teenager's case, the tooth was located in the upper orbital region rather than within the normal dental arch.

Before confirming the diagnosis, doctors considered whether the projections could be associated with a teratoma, a type of tumor that can contain different tissues, including bone and tooth tissue. They also considered whether a foreign object might be lodged in the eyelid.

Imaging and examination of the removed structure helped establish that it was a mature tooth rather than tissue associated with a teratoma.

Why Is This Case Unusual?

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Ectopic teeth have been documented in several locations, including the nasal cavity, chin and maxillary sinus, an air-filled cavity within the cheekbone. Previous reports have also described teeth in the lower part of the eye socket.

However, the doctors said they could not find an earlier report of an ectopic tooth in the superior orbit, the upper region of the eye socket.

“To the best of our knowledge this is the first and only ectopic tooth reported in the superior orbit,” Tanwar told Live Science.

“This was a first not just for us but the world over,” she said of the case. “We were very surprised by it.”

What Causes Ectopic Teeth?

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The doctors could not determine why the tooth developed in this unusual location.

Possible explanations for ectopic tooth development include abnormalities during development, genetic factors, infections and physical trauma. However, the cause in this case remains unknown.

Imaging did not reveal any additional ectopic teeth. Tanwar said the likelihood of the teenager developing another such tooth was low.

Beth Dobbin, who represented Great Britain at the Tokyo Olympics in 2021, now spends more than 22 hours a day in bed.

The 32-year-old retired from athletics in April 2026, describing her illness as “serious” and “life-changing.” She was later diagnosed with myalgic encephalomyelitis (ME), a chronic condition with no known cure or specific treatment.

Dobbin reached the 200m semi-finals at the Tokyo Olympics and won bronze in the 4x200m relay with Scotland at the 2022 Commonwealth Games in Birmingham.

“It's life-decimating like I can't even put into words,” she said. “I feel like I've lost everything.”

Beth Dobbin's Diagnosis with ME

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Dobbin’s health began deteriorating after back-to-back COVID-19 and glandular fever infections in the winter of 2021-22, the BBC

reported.

She experienced worsening fatigue, slower running times and soreness in the glands in her neck and armpits. Initial tests by British Athletics doctors failed to identify the cause.

Despite her symptoms, she continued training in 2022. At the European Championships, she false-started after losing all feeling in her legs while in the starting blocks.

Her condition subsequently worsened. She struggled to stand and spent most of her time in bed. After consulting four or five specialists, she was diagnosed with ME.

Dobbin has been confined to her house and bed since then. She gets out of bed only to eat and use the bathroom. Even conversations, bright lights or loud sounds can trigger a “crash” lasting days or, in severe cases, months. She has left the house just five times this year, the report said.

She now leaves home mainly for medical appointments and blood tests. Even conversations, bright lights and loud sounds can trigger a “crash” that lasts days or, in severe cases, months. She has left home just five times this year, according to the report.

What Is ME?

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ME, also known as chronic fatigue syndrome (CFS), is a complex, chronic illness that can cause severe fatigue, pain, sleep disturbances and problems with thinking and memory. Symptoms do not improve simply with rest, and there is no established cure.

Dobbin rejects the term “chronic fatigue syndrome” because she believes it understates the severity of the condition.

“I wish it was just fatigue, that would be a walk in the park,” she said. “It's so much more than that. If I thought of fatigue in my top 20 symptoms it might just make the cut.”

She described the illness as feeling as though her entire body “is shutting down; it feels like you are a few days from death”.

More than 400,000 people in the UK are thought to have ME, although some estimates put the number above one million. The illness varies in severity, with some people continuing to work or study while others require extensive care.

Dobbin’s illness has also taken an emotional toll on her family.

“I'm just so desperate to help her but I can't because there is nothing. I'd take her anywhere, I'd take her to America if I had to, but there's nothing,” her father, Jim, said.

Beth Dobbin Aims To Raise ME Awareness

Dobbin describes her future as “very bleak” but hopes that greater awareness will lead to better treatment options.

The emergence of long COVID, which shares some symptoms with ME, has brought renewed attention to the illness and increased research funding.

She also wants to highlight the experiences of patients who are dismissed or disbelieved.

“A lot of people that have this illness that I've spoken to have said to me 'I don't get believed, people think I'm lazy'. I've never experienced one person that doesn't believe me and that's because, why would an athlete just suddenly stop after 20 years?”

Infections accounted for an estimated 2.3 million new cancer cases worldwide in 2024, or about 12% of all cancers diagnosed that year, according to a September 2026 study published in The Lancet Oncology. Among these, Helicobacter pylori (H. pylori), a bacterium that infects the stomach, was associated with an estimated 760,000 cancer cases.

A 2025 study by the International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), estimated that 76% of the 15.6 million stomach cancer cases expected over the lifetimes of people born between 2008 and 2017 could be attributable to H. pylori infection if prevention efforts do not improve.

Although infections can contribute to cancer development, they are not the only cause. Genetics, age and non-infectious factors also play a role, Dr. Vivek Kaul, Professor of Medicine in the Gastroenterology & Hepatology Division at the University of Rochester Medical Center, told HealthandMe in an exclusive interview.

“I think, generally speaking, I think H. pylori is a well-known carcinogen, mostly responsible for the development of gastric cancer,” Kaul said.

Is Cancer Increasingly Linked To Infections?

The findings highlight the contribution of infectious agents to the global cancer burden. However, Kaul cautioned against concluding that cancer is increasingly being driven by infections.

“But I don't think it's fair to say that, you know, we are moving towards a more infectious etiology for cancer,” he said.

“Cancer is a multifactorial disease state that develops, most commonly develops from genetic and from non-infectious causes,” Kaul added.

He explained that cancer development also depends on the ability of cells to defend themselves against external threats and genetic mutations.

“In many cases, cancer development comes primarily from genetic and age-related issues and boils down to the individual cell's ability, you know, to fight external attacks, such as from H. pylori type of agents or from genetic mutations,” he said.

Kaul also noted that other infectious agents have been implicated in cancer development.

How Does H. pylori Raise Stomach Cancer Risk?

H. pylori is a bacterium that infects the stomach lining and can persist for years. The infection can cause chronic inflammation and damage to stomach tissue, increasing the risk of gastric cancer.

According to scientists at the International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), H. pylori infection is responsible for an estimated 76% of stomach cancer cases worldwide. The infection often causes no noticeable symptoms, although some people may experience digestive complaints.

The bacterium can spread through contaminated food or water and close contact with infected individuals. In some cases, the infection can cause stomach ulcers. Because many infected people have no symptoms, testing may be needed to identify it.

Can H. pylori Infection Be Prevented From Progressing To Cancer?

The World Gastroenterology Organisation's global guidelines state that eradicating H. pylori before precancerous changes develop can help prevent gastric cancer. This evidence supports test-and-treat screening programmes for young adults in countries with a high disease burden and sufficient resources.

Testing can involve blood, breath or stool tests, depending on the clinical context. People diagnosed with the infection can receive treatment to eradicate the bacterium. Follow-up testing can then confirm whether treatment has worked.

Nobel laureate and gastroenterologist Dr Barry Marshall has also highlighted the potential for early treatment to reduce cancer risk.

“H. pylori is much more than an ulcer organism. If the infection persists for many years, it can cause chronic inflammation in the stomach and increase the risk of gastric cancer. That gives us an opportunity because this is a potentially preventable cause of cancer,” Marshall told PTI.

He stressed the need for wider testing, appropriate treatment and follow-up to ensure the infection has been cleared.

Other Digestive Cancers Are Also A Growing Concern

Beyond infection-associated cancers, Kaul highlighted the rising incidence of several digestive cancers.

“We know that esophageal squamous cancer is another example where we will be close to a million cases by 2035,” he said, pointing to the burden in East Asia, sub-Saharan Africa and South America, including India.

Kaul also identified liver cancer as a growing concern and noted the rise in colorectal cancer among younger people in Western countries. The increase in colorectal cancer among younger adults in the US contributed to recommendations to begin average-risk screening at age 45 rather than 50.

These trends underline the need to address infectious causes of cancer alongside other risk factors, while improving access to prevention, early detection and appropriate care.