Abstract
Influenza virus is transmitted via respiratory expulsions, but detection of infectious virus in such expulsions has been challenging. Here, we describe quantification and genotyping of infectious virus in respiratory particles using a Modular Influenza Sampling Tunnel (MIST). The particles deposit on cell monolayers, enabling culture, quantification, and sequencing of viruses. Concomitantly, water-sensitive paper and fine particle samplers yield respiratory particle counts over a broad size range. Using the MIST, we captured infectious virus from humans experimentally infected with influenza virus on multiple days post-inoculation. The recovered respiratory particles varied in quantity over three orders of magnitude and contained viral genetic variation that was also detected in samples from infected individuals. Expulsion of infectious virus was associated with infectious viral load in saliva and nasopharyngeal swabs and with clinical symptoms. These data reveal the maintenance of viral diversity in expelled aerosols and suggest that heterogeneity among individuals in the magnitude of infectious expulsions may impact forward transmission potential.
Competing Interest Statement
NGR receives funding from Merck, Sanofi, Pfizer, Vaccine Company, Immorna, and consulting fees from Krog &Partners. Merck, CSK is a consultant for Ferring Pharmaceuticals. LCM serves as a consultant for MITRE corporation. None of these funders or consulting agencies were involved in the research described or influenced the studies.
Clinical Trial
NCT05332899
Funding Statement
This work was funded by Flu Lab, NIAID Centers of Excellence for Influenza Research and Response (CEIRR), contract number 75N93021C00017, and internal Emory University funds awarded to NGR. NVM is supported by 1F31AI186480-01. Next generation sequencing services were provided by the Emory NPRC Genomics Core which is supported in part by NIH P51 OD011132. Sequencing data was acquired on an Illumina NovaSeq 6000 funded by NIH S10 OD026799.
Source: MedRxIV, https://www.medrxiv.org/content/10.1101/2025.11.03.25339190v1
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