A Review of the Role of Pollen in COVID-19 Infection

There is current interest in the role of ambient pollen in the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2 or COVID-19) infection risk. The aim of this review is to summarise studies published up until January 2023 investigating the relationship between airborne pollen and the risk of COVID-19 infection. We found conflicting evidence, with some studies showing that pollen may increase the risk of COVID-19 infection by acting as a carrier, while others showed that pollen may reduce the risk by acting as an inhibiting factor. A few studies reported no evidence of an association between pollen and the risk of infection. A major limiting factor of this research is not being able to determine whether pollen contributed to the susceptibility to infection or just the expression of symptoms. Hence, more research is needed to better understand this highly complex relationship. Future investigations should consider individual and sociodemographic factors as potential effect modifiers when investigating these associations. This knowledge will help to identify targeted interventions.

[1]  A. Lowe,et al.  The role of short‐term grass pollen exposure in food skin‐prick test reactivity, food allergy, and eczema flares in children , 2022, Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology.

[2]  A. Ramazani,et al.  Screening of honey bee pollen constituents against COVID-19: an emerging hot spot in targeting SARS-CoV-2-ACE-2 interaction , 2022, Natural product research.

[3]  A. Lowe,et al.  Children with food allergy are at risk of lower lung function on high pollen days. , 2022, Journal of Allergy and Clinical Immunology: In Practice.

[4]  A. Kroes,et al.  Environmental factors and mobility predict COVID-19 seasonality in the Netherlands , 2022, Environmental Research.

[5]  S. Sánchez‐García,et al.  Effect of the SARS-CoV-2 pandemic on the control and severity of pediatric asthma. , 2022, Allergologia et immunopathologia.

[6]  G. Liccardi,et al.  Use of face masks and allergic rhinitis from ragweed: Why mention only total pollen count and not air pollution levels? , 2021, International Forum of Allergy and Rhinology.

[7]  J. Davies,et al.  Thunderstorm Asthma in Seasonal Allergic Rhinitis: The TAISAR study. , 2021, The Journal of allergy and clinical immunology.

[8]  K. Nozu,et al.  Impact of the State of Emergency during the COVID-19 Pandemic in 2020 on Asthma Exacerbations among Children in Kobe City, Japan , 2021, International journal of environmental research and public health.

[9]  M. Lanari,et al.  Understanding the environmental factors related to the decrease in Pediatric Emergency Department referrals for acute asthma during the SARS‐CoV‐2 pandemic , 2021, Pediatric pulmonology.

[10]  A. Lowe,et al.  Is asthma associated with COVID-19 infection? A UK Biobank analysis , 2021, ERJ Open Research.

[11]  C. Kara,et al.  The effect of face mask usage on the allergic rhinitis symptoms in patients with pollen allergy during the covid-19 pandemic , 2021, American Journal of Otolaryngology.

[12]  R. B. Shah,et al.  Competing Bioaerosols May Influence the Seasonality of Influenza-Like Illnesses, including COVID-19. The Chicago Experience , 2021, Pathogens.

[13]  A. V. Valero Santiago,et al.  Is environmental pollen concentration a risk factor for SARS-CoV-2 infection? , 2021, Journal of investigational allergology & clinical immunology.

[14]  T. Zuberbier,et al.  Face masks suitable for preventing COVID-19 and pollen allergy. A study in the exposure chamber , 2021, Allergo Journal International.

[15]  S. Fujieda,et al.  Regulation of the Expression of SARS-CoV-2 Receptor Angiotensin-Converting Enzyme 2 in Nasal Mucosa , 2021, American journal of rhinology & allergy.

[16]  J. Ščevková,et al.  Seasonal variation in the allergenic potency of airborne grass pollen in Bratislava (Slovakia) urban environment , 2021, Environmental Science and Pollution Research.

[17]  C. Mueller,et al.  Portable HEPA Purifiers to Eliminate Airborne SARS-CoV-2: A Systematic Review , 2021, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[18]  D. Drikakis,et al.  On pollen and airborne virus transmission , 2021, Physics of fluids.

[19]  E. Cicinelli,et al.  Updates on Children with Allergic Rhinitis and Asthma during the COVID-19 Outbreak , 2021, Journal of clinical medicine.

[20]  N. Quaranta,et al.  COVID-19 lockdown and seasonal allergic rhinitis: our experience in 40 patients , 2021, Acta bio-medica : Atenei Parmensis.

[21]  C. Betsch,et al.  The human factor between airborne pollen concentrations and COVID-19 disease dynamics , 2021, Proceedings of the National Academy of Sciences of the United States of America.

[22]  S. Bavbek,et al.  Coincidence of pollen season and coronavirus disease 2019 pandemic: less time outdoors – lesser allergy symptoms in 2020 , 2021, Asia Pacific allergy.

[23]  A. Lowe,et al.  Lung Function Levels Influence the Association between Obesity and Risk of COVID-19 , 2021, American journal of respiratory and critical care medicine.

[24]  S. Mor,et al.  Does airborne pollen influence COVID-19 outbreak? , 2021, Sustainable Cities and Society.

[25]  M. Sofiev,et al.  Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe , 2021, Proceedings of the National Academy of Sciences.

[26]  S. Majumdar,et al.  A global panel database of pandemic policies (Oxford COVID-19 Government Response Tracker) , 2021, Nature Human Behaviour.

[27]  A. Lowe,et al.  Outdoor pollen‐related changes in lung function and markers of airway inflammation: A systematic review and meta‐analysis , 2021, Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology.

[28]  P. Marquet,et al.  Socioeconomic status determines COVID-19 incidence and related mortality in Santiago, Chile , 2021, Science.

[29]  T. An,et al.  The source and transport of bioaerosols in the air: A review , 2020, Frontiers of Environmental Science & Engineering.

[30]  Maritza Vasquez Reyes.  The Disproportional Impact of COVID-19 on African Americans , 2020, Health and human rights.

[31]  E. V. van Gorp,et al.  Can pollen explain the seasonality of flu-like illnesses in the Netherlands? , 2020, Science of The Total Environment.

[32]  J. Simon,et al.  No SARS-CoV-2 detected in air samples (pollen and particulate matter) in Leipzig during the first spread , 2020, Science of The Total Environment.

[33]  M. Matusiak,et al.  Expression of SARS-CoV-2 entry receptors in the respiratory tract of healthy individuals, smokers and asthmatics , 2020, Respiratory Research.

[34]  W. Lima,et al.  Bee products as a source of promising therapeutic and chemoprophylaxis strategies against COVID‐19 (SARS‐CoV‐2) , 2020, Phytotherapy research : PTR.

[35]  A. Lowe,et al.  Is short‐term exposure to grass pollen adversely associated with lung function and airway inflammation in the community? , 2020, Allergy.

[36]  S. Mukherjee,et al.  In silico studies on the comparative characterization of the interactions of SARS‐CoV‐2 spike glycoprotein with ACE‐2 receptor homologs and human TLRs , 2020, Journal of medical virology.

[37]  P. Gergen,et al.  Association of respiratory allergy, asthma, and expression of the SARS-CoV-2 receptor ACE2 , 2020, Journal of Allergy and Clinical Immunology.

[38]  M. Hoogeveen.  Pollen likely seasonal factor in inhibiting flu-like epidemics. A Dutch study into the inverse relation between pollen counts, hay fever and flu-like incidence 2016–2019 , 2020, Science of The Total Environment.

[39]  J. Lelieveld,et al.  COVID-19 lockdowns cause global air pollution declines , 2020, Proceedings of the National Academy of Sciences.

[40]  A. Lowe,et al.  A systematic review of the role of grass pollen and fungi in thunderstorm asthma. , 2019, Environmental research.

[41]  C. Akdis,et al.  Pollen exposure weakens innate defense against respiratory viruses , 2019, Allergy.

[42]  E. Holmes,et al.  RNA Viruses in Hymenopteran Pollinators: Evidence of Inter-Taxa Virus Transmission via Pollen and Potential Impact on Non-Apis Hymenopteran Species , 2010, PloS one.

[43]  Lirong Chen,et al.  Small Molecules Blocking the Entry of Severe Acute Respiratory Syndrome Coronavirus into Host Cells , 2004, Journal of Virology.