key: cord-1028190-ig32u12v
authors: Damialis, Athanasios; Gilles, Stefanie; Traidl‐Hoffmann, Claudia
title: Adding the variable of environmental complexity into the COVID‐19 pandemic equation
date: 2021-06-15
journal: Allergy
DOI: 10.1111/all.14966
sha: 8e0b70742975cf45947c440914b53817df2269c1
doc_id: 1028190
cord_uid: ig32u12v

In a recently published data-orientedstudyin March 2021, a relationship between SARS-CoV-2 infection rates and airborne pollen concentrationswas detected [1]. The studyincluded a data compilation of airborne pollen concentrations and SARS-CoV-2 infection numbers across 31 countries from both hemispheres and all inhabited continents from an inter-disciplinary team consisting of 154 scientists. The salient finding wasa significant and positive correlation between SARS-CoV-2 infection rates and airborne pollen concentrations in the spring of 2020 for the majority of examined countries, in synergy with air temperature and/or relative humidity (Fig. 1).

In a recently published data-oriented study in March 2021, a relationship between SARS-CoV-2 infection rates and airborne pollen concentrations was detected. 1 The study included a data compilation of airborne pollen concentrations and SARS-CoV-2 infection numbers across 31 countries from both hemispheres and all inhabited continents from an interdisciplinary team consisting of 154 scientists. The salient finding was a significant and positive correlation between SARS-CoV-2 infection rates and airborne pollen concentrations in the spring of 2020 for the majority of examined countries, in synergy with air temperature and/or relative humidity ( Figure 1 ). This synergy of environmental factors could explain on average 44% of the whole variability in infection rates, most frequently with a delay effect of 4 days, after the contact influence was excluded (as expressed here via lockdown). Sociodemographic effects (population density and lockdown), being proxies of contact, were proven key players in the virus spreading: lockdown regimes, particularly when adopted early, were on average reducing infection rates to half. Of note, the lowest infection rates were observed at sites with low pollen concentrations during the study period. At these sites, not only pollen was not correlated with the infection numbers, but also frequently no other environmental factor either. This was the case on the Southern Hemisphere, or in Northern Europe (wherever and whenever was still too cold or humid). While the study period was limited to early spring (1 January to 8 April 2020), the strength was the inclusion of data from almost all operating pollen monitoring stations across the world, which made our data set the best possible ever for such an explorative study, and allowing for the investigation of spatial as well as temporal relationships.

The conception of a potential relationship between airborne pollen and SARS-CoV-2 infections was based on recent findings, published in November 2019. 2 There, we showed that pollen compromises the innate antiviral defence of airway epithelia by diminishing antiviral type-I and type-III interferons. This was con- 1 and key findings. Data on airborne pollen concentrations, weather, SARS-CoV-2 infections, population density and lockdown measures were collected from 1 January to 8 April 2020. The data were collected from 248 monitoring sites across 31 countries on five continents. Apart from the expected protective effect of lockdowns (grey vertical bar), significant and positive correlations of SARS-CoV-2 infection rates were observed with airborne pollen during warmer (horizontal, redgradient bar) and drier (horizontal, blue-gradient bar) weather

Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe

Pollen exposure weakens innate defense against respiratory viruses

Modelling airborne transmission of SARS-CoV-2: risk assessment for enclosed spaces

Comparable seasonal pattern for COVID-19 and flu-like illnesses

One Health in allergology: a concept that connects humans, animals, plants and the environment

Advances and novel developments in environmental influences on the development of atopic diseases

Anthropogenic climate change is worsening North American pollen seasons