In May, the scenario repeats itself, more or less identical every year. Heavy jackets are put away in the closet and short sleeves are preferred, with the feeling that the winter ailments are finally over . Then, however, someone starts coughing, emitting, if infected, respiratory viruses that spread in bioaerosols . Strange? Not so much. Contrary to what many think, May is not a clear dividing line between “flu season” and “safe period .” It’s more of a transition zone , where several factors overlap.
The “End of the Flu” Myth: What Really Happens in Spring?
The idea that the flu risk ends with the arrival of spring is convenient, but not entirely correct . The problem isn’t that the virus is hiding: it’s that we’re letting our guard down . Understanding the dynamics of viral circulation in spring is the first step to consciously protecting ourselves and others.
The survival of respiratory viruses under moderate climatic conditions.
Respiratory viruses do n’t require extreme conditions to circulate. Indeed, indoors often provide an ideal environment : recycled air, the presence of many potential hosts, and air exchange that isn’t always adequate. Environmental factors such as relative humidity can also influence pathogen transmission, contributing to an overall risky environment. During the “transitional” months, moreover, we still spend a lot of time in confined spaces , such as offices, schools, and on public transportation. In other words, the outside climate changes, but the dynamics of indoor spaces remain the same .
Statistics and data: late flu peaks in recent years.
Epidemiological surveillance data show that in recent years, in Italy, flu peaks have also affected the first few weeks of mild temperatures . A striking finding emerges from the 2021-2022 season, when the peak arrived in spring rather than winter . For 2026, on the other hand, influenza positivity is documented beyond the classic period , correlating with the coexistence of multiple viral types (including rhinovirus and parainfluenza virus ) . This is not an anomaly, but a consolidating trend, favored by multiple factors: the circulation of viral strains with different seasonality , greater mobility of people in the spring months, and the progressive reduction of acquired immune protection (for those who have been vaccinated).
Temperature fluctuations and immune defenses: why we’re more vulnerable in May.
The immune system is modulated by environmental, hormonal, nutritional, and behavioral factors. May is characterized by frequent and marked temperature changes , which impact the human body’s immune response. Specifically, this constant climatic oscillation severely challenges thermoregulation mechanisms and, indirectly, the body’s natural defenses.
The impact of “dressing in layers” on body thermoregulation.
Adding and removing layers of clothing throughout the day is a good strategy for dealing with unstable weather, but it’s not always effective . The problem is that changes in clothing often lag behind temperature changes: you sweat wearing a sweatshirt, only to suddenly feel a cold draft in your short sleeves. These micro-temperature fluctuations induce peripheral vasoconstriction in the skin, which can temporarily reduce the effectiveness of the mucosal immune system : the first line of defense located in the upper airways . It’s not the cold itself that causes the flu, but the temporary lowering of defenses makes it easier for pathogens to take hold , especially in those already exposed to a respiratory virus fluctuating nearby.
Seasonal stress and lowering of the natural barriers of the upper airways.
The upper airways (i.e., nose, pharynx, and larynx) are active immune barriers , equipped with ciliated epithelium, mucus, and secretory immunoglobulins (IgA) capable of trapping and neutralizing pathogens before they reach the lungs. In spring, these barriers undergo a dual stress . On the one hand, pollen and allergens in the air induce local microinflammations that alter the permeability of the nasal and pharyngeal epithelium . On the other, accumulated fatigue over the course of the year lowers secretory immunoglobulin levels, making the upper respiratory tract a more favorable entry point for viruses .
The air conditioning paradox: when cool air becomes a viral vector.
Turning on the air conditioning is an understandable response to the discomfort of the first heat, although it hides an unfavorable aspect: air conditioning systems, if not properly managed , can become one of the main vectors of viral transmission in indoor air.
How ventilation systems transport droplets into offices.
When an infected person speaks, sneezes, or simply breathes , they release a combination of droplets of different sizes into the air . Larger droplets, known as droplets , fall rapidly due to gravity. Smaller droplets, known as aerosols , remain suspended in the air for many minutes, sometimes hours, especially in closed environments with poor air circulation. Centralized air conditioning systems, designed to ensure thermal comfort rather than to sanitize the air , can recirculate these droplets within a single room, increasing the radius of spread of viral particles . In a typical open space, a single infected person can theoretically infect, via bioaerosols , anyone within the path of the air flows generated by the air conditioner.
The importance of maintenance and the limitations of traditional filters.
Regular maintenance of air conditioning systems (e.g., cleaning filters, checking ducts, etc.) is essential for reducing the level of biological contaminants in the air. However, many Italian commercial and residential buildings do not comply with the maintenance cycles recommended by manufacturers. Furthermore, the standard filters installed in mid-range air conditioners, designed to trap dust and dander, are unable to block extremely small particles such as viruses .
High-class HEPA filters represent a significant improvement , but their installation requires technical adaptations and additional costs that many home and business users are not prepared to face. The practical result is that the indoor air in air-conditioned environments often remains unsanitized , with a variable but significant microbial load.
The impact of pollen: how allergies facilitate the entry of viruses.
May is the height of pollen season in much of Italy. Grasses, birch, cypress, pellitory of the wall: the concentration of allergenic particles in the air reaches its highest levels precisely in the mildest spring weeks. For millions of Italians suffering from allergic rhinitis or allergic asthma, this period is already an ordeal in itself. But there is an additional, often overlooked risk: pollen allergies literally open the door to respiratory viruses .
Hay fever: an open highway for pathogens.
When pollen comes into contact with the mucous membranes of a sensitized individual, it triggers an IgE-mediated inflammatory reaction that causes swelling of the nasal mucosa, hypersecretion of mucus, repeated sneezing, and often microlesions of the ciliated epithelium. This combination of events represents, from the perspective of respiratory viruses, a nearly ideal condition for attachment : the mucosal barrier is compromised, the local immune system is already busy responding to allergens, and the cilia, responsible for “sweeping away” pathogens, are impaired in function.
The inflamed nasal epithelium is physically more permeable , with loose intercellular junctions that allow viruses to more easily penetrate the submucosal layers and initiate replication .
Why allergy sufferers should pay double attention to indoor air.
An initial response to pollen season is to close windows and seek refuge in air-conditioned rooms. This strategy, while useful for protecting against allergens, risks increasing exposure to indoor biological contaminants , including viruses carried by air circulation systems.
The allergy sufferer therefore finds himself in an uncomfortable situation: opening windows means exposing their mucous membranes to pollen; keeping them closed means relying on indoor air that is often unfiltered and potentially rich in viral agents . The solution cannot simply be “open or not open”: it requires an active approach to indoor air quality , which goes beyond the use of windows and conventional air conditioning.
Active protection with e4life: the technology that doesn’t fear the change of seasons.
Once we understand the risks, it’s clear that prevention cannot be relied on one-off measures . We need technological solutions designed to continuously and proactively address the air quality in the environments where we live and work.
This is where e4life comes in , the air sanitization device that does not follow the rhythms of the seasons, but works continuously to ensure a safe environment every day of the year.
Constant sanitization without having to open windows wide (and letting pollen in).
The principle behind e4life is simple but revolutionary in its practical application: treating the air in the environment as we treat the water we drink: with a continuous , not episodic, purification process .
The core technology, e4shield ™ , generates electromagnetic waves capable of neutralizing viruses dispersed in bioaerosols , without producing chemical residues that are dangerous to humans or pets (in keeping with the “One Health” philosophy). Unlike conventional air purifiers, which passively filter indoor air, e4life works actively , reaching even the corners of the room that no artificial airflow passes through.
For those with pollen allergies, this means not having to choose between open windows and compromised air quality. The indoor environment remains sanitized regardless of whether windows are open , providing daily protection for the occupant without imposing rigid behaviors.
E4life as the definitive solution for a healthy spring.
In terms of health risks, spring is undoubtedly “uncomfortable”: it’s not enough to protect yourself from viruses, nor just from pollen, nor just from faulty air conditioning. It’s the combination of these factors that makes May a treacherous month.
In this context, e4life technology responds with an integrated solution . In domestic settings, it reduces the viral load in indoor air , protecting the most vulnerable during hours spent at home. In workplaces, the technology complements or replaces conventional ventilation systems , reducing the risk of viral spread among colleagues.
e4life’s approach places air quality among the fundamental variables of daily well-being, acting continuously and in any season. Responding to different needs, the technology lends itself to different applications, ensuring environmental and/or individual protection . Want to learn more? Visit the website and discover the solution best suited to your needs .
