“More pollen concentrated in the air, more infections,“The concentration of pollen in the air appears to have a connection with the Coronavirus. These are the results of a study carried out between March and April last year, through 250 survey stations around the world.
From this analysis it would appear that pollen weakens the first line of defense against respiratory viruses, regardless of whether or not you suffer from allergies.
“When the pollen increases, there are more infections. When it decreases, they decrease “, confirms María del Mar Trigo, from the University of Malaga and co-author of the study.
The work overlapped the daily amount of cereals from 248 aerobiological stations in 31 countries with that of the number of infections in the closest area (local, regional and national).
The correlation between pollen and infections has been verified in almost all the areas studied, for the most part located in Europe. The study also gives precise percentages – an increase 100 grains per cubic meter of air leads to a 4% increase in the number of cases after three to four days.
Athanasios Damialis, head of aerobiology at the Technical University of Munich (Germany), received pollen concentration data from more than 100 colleagues from around the world. From the results it is observed that where or when the lockdown has been strengthened, the parallel variation of pollen and contagion has weakened.
In Mediterranean areas “high temperatures and drought may have eliminated the effect of the virus independently of other factors such as pollen”. At the end of the summer and the beginning of the autumn, the second wave of the pandemic took place, fueled by tourism, school or the arrival of the cold. And this was the time of the lowest relative pollen concentration.
In any case, all allergists have recommended the use of masks for years, regardless of the virus to protect themselves from pollen and agree that the first factor of infection is interpersonal contact.
What we are now trying to understand in more depth is whether pollen weakens the immune system, facilitating the contagion from Coronavirus.
In September 2019, scientist Stefanie Gilles published a scientific article on the relationship between pollen concentration and two respiratory viruses, rhinoviruses (cause of the common cold) and respiratory syncytial virus and found that viral replication in both human and human cells in those of mice exposed to pollen and rhinoviruses is significantly increased.
Stefanie Gilles, researcher at the University of Munich explained the phenomenon in this way: “Pollen is mainly known as an allergen, but what we have studied is how it affects non-allergic people as well. We know, for example, that if we spray birch pollen extract on the nose of non-allergic people, many genes involved in the defense against viruses are deregulated, which implies that the antiviral immune response is reduced ”. It is not yet known which pollen component is the cause, “but we know that it is not the same that causes allergies”.
Gilles pointed out that this unknown element “causes less production of antiviral interferons during a viral infection”. Furthermore, it is still to be investigated whether what has been observed in two respiratory viruses would be valid for Coronavirus, another respiratory virus ”.
Mixed opinions on the study among many virologists. However, some consider the work of great importance. “We knew our patients had more colds during the pollen season, but it was thought to be a side effect of the allergic reaction. This work, however, highlights that pollen eliminates our first line of defense whether you are allergic or not ”.