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Despite living alongside viruses for millennia, numerous misconceptions persist regarding their behavior and how best to defend against them. A leading virologist clarifies four common myths, emphasizing the importance of proactive prevention.
Viruses are a constant presence in our lives, particularly during the fall and winter months when common colds circulate through schools, workplaces, and public transportation. Simultaneously, reports of increased influenza spread begin to surface. However, despite this long-standing coexistence, outdated beliefs about viruses and protection strategies continue to circulate.
Myth 1: “Exposure to Viruses Strengthens the Immune System”
The notion that deliberately exposing oneself to infections “trains” the immune system is a recurring idea, but it’s an oversimplification according to scientific understanding. While our immune systems require stimulation, this is naturally achieved through everyday environmental contact and, crucially, through vaccinations.
Repeated infections in settings like preschools or workplaces do not provide a beneficial boost. There is no “bonus system” for enduring multiple illnesses; each infection carries inherent risks. Getting sick is always a risk, and experiencing a disease does not guarantee better protection than vaccination against the same ailment. Contagious viruses like RSV, influenza, and COVID-19 can lead to serious complications, even in healthy individuals, with potential consequences including meningitis, pneumonia, and ear infections. Therefore, avoiding every viral disease that can be avoided is paramount. Vaccines offer a safe and controlled method for building immunity, undergoing rigorous review before approval to ensure benefits outweigh risks.
Myth 2: “RSV Only Affects Young Children”
Respiratory syncytial virus (RSV) is widely known as an “infant virus,” and it is a leading cause of severe respiratory infections in young children. However, the belief that RSV is solely dangerous for small children is inaccurate.
Older adults and individuals with compromised immune systems are often affected just as severely, and sometimes even more so. In Sweden, significantly more elderly individuals die from RSV annually compared to infants. Seniors are also more susceptible to infection and experience prolonged symptoms, with a higher likelihood of co-morbidities – where RSV exacerbates existing health conditions. For an elderly person, an RSV infection can pose risks comparable to influenza, including pneumonia, breathing difficulties, and hospitalization. Globally, RSV is responsible for tens of thousands of deaths among the elderly each year. Vaccines, specifically those designed for older adults, are available to mitigate these risks.
Myth 3: “After an Infection, You Are Immune Forever”
Many assume that recovering from a viral infection grants lifelong protection. While this holds true for some viruses, like measles, it’s not universally applicable.
Influenza viruses, for example, are constantly evolving. The immune system learns to recognize a specific viral variant, but mutations can render that immunity less effective. This explains why individuals can contract influenza multiple times, even within the same season. Similarly, RSV provides only short-term protection after infection, lasting just a few months, unlike the years of protection offered by vaccines. Furthermore, some viruses, like chickenpox, remain dormant in the body after initial infection and can reactivate later in life as shingles. Immunity can wane over time for several infections, necessitating booster doses of vaccines to maintain protection.
Myth 4: “You Catch a Cold From Being Cold”
The common parental advice to “put on properly, so you don’t catch a cold” is misleading. Simply being cold and wet is insufficient to cause a cold; a virus is also required.
However, colds are more prevalent during colder months because people spend more time indoors, in closer proximity, and viruses spread more easily in dry air. Cold temperatures can also affect the body’s defenses, constricting blood vessels in the nose, reducing blood flow and immune cell activity in the mucous membranes, and increasing susceptibility to viral infection. Cold, dry air can further irritate these membranes, facilitating viral entry.
These factors underscore that our immune system is dynamic, not static, and that science-based preventative care remains the best defense against both familiar and emerging viruses.
Lennart Svensson, professor emeritus in virology at Linköping University and the Karolinska Institutet, emphasizes the importance of proactive measures in protecting against viral illnesses.
