Paola Brown was about 3 years old when a neighborhood child came down with measles, and her mother took her over to be exposed. Years later, when Brown had children of her own, she became fearful of infections and responded the way she’d been taught by suppressing the fevers that often accompany common childhood illnesses.
It’s conditioned parental behavior: Your toddler spikes a 102-degree fever, and you reach for fever-reducing medication or find other ways to eliminate discomfort.
Those common fevers, however, and the stream of colds, flus, and childhood bugs that come with them are actually building a fortress of immunity that could protect against serious diseases decades later.
Some research suggests that fevers, which accompany common childhood infections such as measles and chicken pox, could be a biologically meaningful part of the process. Research has linked both fevers and exposure to certain childhood infections with lower risk of certain cancers, heart disease, asthma, and allergies in adulthood—raising questions about why we try to avoid common immune-activating events that pose little harm.
The Hygiene Hypothesis
Known as the hygiene hypothesis, the theory suggests that early exposure to microbes helps train the immune system to distinguish threats from harmless substances. Being too hygienic or isolated from microbes does not provide the training ground your immune system needs to build tolerance.“Most routine childhood infections are self-limited and part of normal immune development, especially in healthy children,” integrative pediatrician and Epoch Health contributor Dr. Joel “Gator” Warsh told The Epoch Times.
Vaccines, antibiotics, and antiviral treatments represent a trade-off. While they have reduced the incidence of severe infections, they also correspond to rising rates of asthma and allergies, the authors noted.
Fever’s Role in Immunity
Fever itself may play a critical role in immunity. Children who had fevers before their first birthday were less likely to have allergies five or six years later, according to a study published in the Journal of Allergy and Clinical Immunology.Fevers trigger a surge in circulating cytokines, signaling proteins that control inflammation and are believed to help modulate immune responses to allergens.
“The complexity of these cytokine changes makes it hazardous to speculate on a precise mechanism for the association between fever and allergic sensitization,” the authors wrote, adding that if fevers are indicative of intense immune stimulation, then each fever could further reduce the likelihood of developing allergies.
Where Science Has Made Connections
Several studies have found more specific associations between common childhood illnesses and improved health outcomes.Lower Risk of Cancers
Children with at least one infection-related hospital contact in their first two years had a lower risk of cancer in early to mid-adulthood compared with children without an infection, according to a Danish study of more than 68,000 people published in Cancer Epidemiology.Fewer Cases of Heart Disease
The hygiene hypothesis might also explain why the immune system is able to suppress inflammation in the arterial wall.The risk of acute coronary events decreased among those with childhood infectious diseases—chickenpox, scarlet fever, measles, mumps, mononucleosis, and rubella—according to the study findings. The more infections one had, the lower the risk of heart events.
Reduction of Asthma and Allergies
The association between early childhood infections and the development of allergies is more nuanced. While repeated lower respiratory tract infections early in life were associated with asthma and wheezing at age 7 in a study published in BMJ, other infections were associated with reduced asthma and respiratory symptoms.The strongest protective effect was found among children who had recurrent runny noses and infections caused by herpes viruses in their first year. Asthma diagnoses were also less common in a small number of children who had measles.
Why Parents Fear Fevers
Most parents want to medicate fevers immediately—understandable given that it’s common for children to have two to six fevers a year in their first three years.One mother in the study blamed health care professionals: “They never told me: ‘Stay calm because what matters most is that the child is well, not just that the fever goes down.’ Instead, the message is: ‘Paracetamol first, ibuprofen if that doesn’t work, and alternate between the two.’”
Paola Brown, a homeopathy educator, described the common practice of immediately medicating a child’s fever as a culturally driven response rooted in parental anxiety. After researching a supportive versus controlling approach to fevers, she opted to prioritize hydration and rest over antipyretics such as paracetamol.
“Parents will medicate the child, but what they’re really medicating is their anxiety,” she told The Epoch Times.
Brown said the change in her own approach to her children’s fevers coincided with what she calls “the fever years” with her son, who had black tarry stools as a toddler and test results that made doctors suspect he had inflammatory bowel disease. Yet when she began letting his immune system fight off bugs naturally, his bowel movements normalized.
A Cautious Approach
While there may be benefits to getting certain early childhood illnesses, they are not harmless or positive for every child, Warsh said. Infection severity, timing, and the child’s underlying health factor into reactions.“You only benefit if the child survives the infection and recovers without serious complications,” he said. “And there may be downstream effects we don’t yet fully understand.”
Fevers in infants less than 2 months old require prompt medical evaluation. Other situations when it’s appropriate to seek care include fevers above 104 degrees Fahrenheit, fevers of 100.4 degrees Fahrenheit for more than 48 hours in children younger than 2, fevers lasting more than three days in children older than 2, signs of dehydration, and fevers accompanied by seizures. Additionally, children whose immune system is compromised because of steroids, cancer, or sickle cell disease should be seen promptly.
What Science Still Doesn’t Know
Much of the research on the benefits of childhood illnesses is speculative, and more studies are needed, Warsh noted.Long-term studies should examine how infection patterns, timing, severity, and vaccination status affect downstream autoimmune, allergic, and metabolic health outcomes, he added. Studies on vaccines need clarity on dose, sequence, and context—not just whether they prevent specific diseases.
Natural infections typically trigger broader innate and adaptive immune responses than vaccines, which narrowly target specific pathogens for controlled immune responses. Both shape immunity differently, Warsh said, with long-term benefits being far from understood.
However, what is better understood is that well-nourished, healthy children tend to fare better when they get sick compared with metabolically stressed children suffering from chronic inflammation. Infection context is important and includes nutrition, sleep, stress, microbiome health, toxin exposure, and genetics, he said.
“The conversation shouldn’t be ‘infections: good or bad,’ but when, how severe, and in what biological environment.”







