Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe
Authors: Nicolas Bruffaerts
Ben Keaney
Ingrida Šaulienė
Ozlem Goksel
COVID-19/POLLEN study group
S Celenk
Monica González-Alonso
Nestor González Roldán
Mykyta Bortnyk
Jeroen T M Buters
Catherine Helen Pashley
B Clot
László Makra
Maria Louna-Korteniemi
Maximilian Bastl
Letty A de Weger
Agnieszka A Lipiec
Anna Bordin
Ahmed Ismail Manjra
C A Skjøth
Dorota Myszkowska
Malgorzata Puc
Antonio Meriggi
Jack Satchwell
D Vokou
Alberto Pini
Antonio Picornell
Paolo Marraccini
J Belmonte
José Oteros
Anna Agnieszka Rapiejko
German Dario Ramon
O Rybníček
Sanjay Kamboj
Guido Marcer
Tuncay Goksel
Franziska Kolek
Gilles Oliver
Agneta Ekebom
Anja Simčič
Beatriz Tavares
Marta Recio
Viktoria Sofieva
Arturo H Arino
Donát Magyar
Elena Severova
Barbara Stjepanovic
Jesús Rojo
Fiona A Symon
Aydar Acar Sahin
Mikhail Sofiev
Valentina Ceriotti
Fabiana Cristofolini
Linda B Ford
Peng Jia
Susanne Dunker
Maria P Plaza
Beverley Adams-Groom
Loretta Pace
Dariusz Jurkiewicz
Santiago Fernandez-Rodriguez
Krystyna Piotrowska-Weryszko
Vivien Leier-Wirtz
Simon Haberle
Carmen Galan
Victoria Miller
Agnieszka Grinn-Gofroń
V Rodinkova
Pamela Burton
Frances Coates
Linnea Toiviainen
Duygu Yazici
Jozef Dušička
Maria Del Mar Trigo
Concepcion de Linares
Wayne Wilhelm
Anabel Pérez-de-Zabalza
Annika Saarto
Ana Cristina Rodrigues Costa
Ana Večenaj
Beatriz Lara
Ricardo João Ratola Capela Deus
Arnold J H van Vliet
Jae-Won Oh
K Rasmussen
Ewa Kalinowska
Elżbieta Weryszko-Chmielewska
M Thibaudon
Elsa Caeiro
Athanasios Charalampopoulos
Robert Anthony Gomez
Jana Ščevková
Olena Palamarchuk
Maryna Yasniuk
Matthias Werchan
Branko Sikoparija
Alberto Rodríguez-Fernández
Werner Hoek
Tamás Szigeti
Jonathan Peter
Mieke M J F Koenders
Manuel Branco Ferreira
Nhan Pham-Thi
Andreja Kofol Seliger
Shanice van Haeften
Stefan Gilge
Ulas Uguz
Janet M Davies
Lewis H Ziska
Karl-Christian Bergmann
Å Dahl
Stefanie Gilles
Thomas Hornick
Antonella Cristofori
Monika Ziemianin
Łukasz Grewling
Daniela Bayr
Joao Almeida Lopes Fonseca
Maria Cristina Tacca
Sigrid Kaschuba
Delia Fernández
Patricia Cervigon Morales
Paolo Mascagni
Luis Ruiz Valenzuela
Elena Gottardini
Andelija Milic
Cansin Sackesen
Dilys Berman
Paul J Beggs
Sanna Pätsi
Piotr Rapiejko
Olga Sozinova
Dawn Jurgens
Dóra Kajitor-Apatini
Estrella Robles
Nur Munevver Pinar
José María Moreno Grau
Barbora Werchan
Leonard Bielory
Rosa Pérez-Badia
Irene Gomes Câmara Camacho
Janka Lafférsová
Constance Helen Katelaris
Lucie Hoebeke
Antonia Gabaldon Arguisuelas
Stanley Finemann
Ana Catarina Galveias Jorge
Javier F Rodríguez-Rajo
Claudia Traidl-Hoffmann
Maira Bonini
Aykut Guvensen
Helena Ribeiro
Celia Maria Miguel Antunes
Laura Beatriz Barrionuevo
Athanasios Damialis
Journal: Proceedings of the National Academy of Sciences of the United States of America (2021)
Discipline: Multidisciplinary
Keywords: COVID-19; aerobiology; pollen; viral infection.
Affiliations: Chair of Environmental Medicine, Technical University of Munich, Augsburg 86156, Germany; ., Institute of Environmental Medicine, Helmholtz Centre Munich, Augsburg 86156, Germany., Department of Environmental Medicine, Faculty of Medicine, University of Augsburg, Augsburg 86156, Germany., Chair of Environmental Medicine, Technical University of Munich, Augsburg 86156, Germany., Finnish Meteorological Institute, Helsinki FI-00101, Finland., Mailman School of Public Health, Columbia University, New York, NY 10032., Center for Environmental Prediction, Rutgers University, New Brunswick, NJ 08901., Environmental and Occupational Health Science Institute, Rutgers University, Piscataway, NJ 08854., Medicine, Allergy, Immunology and Ophthalmology Department, Hackensack Meridian School of Medicine, Nutley, NJ 07110., New Jersey Center of Science, Technology and Mathematics, Kean University, Union, NJ 07083., Institute of Economics and Rural Development, Faculty of Agriculture, University of Szeged, Szeged 6720, Hungary., Department of Botany and Plant Physiology, University of Malaga, Malaga 29016, Spain.

Abstract:  Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown-no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m3 resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen-virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations. 

Retracted: No

PubPeer comments:
 Why should pollen exposure lead to an increase in viral infections? Coincidence isn t causation ... The methods do not give the source of the SARS_CoV2 infection (test rate, geographical distance to pollen station), the speculation about any immune effects can t substantiated, R$2$ values are ridiculous low and looking at a full year and [not just spring season] showed that there was no pollen effect at the much larger second wave in Germany. [verdict] , 
 The Figure 5 presents an evident symmetry for Poland s sub-plot. Such symmetry does not exist in other sub-plots. ![file] ,