[HTML][HTML] Prophylactic intranasal administration of a TLR2/6 agonist reduces upper respiratory tract viral shedding in a SARS-CoV-2 challenge ferret model
PC Proud, D Tsitoura, RJ Watson, BY Chua… - …, 2021 - thelancet.com
EBioMedicine, 2021•thelancet.com
Background The novel human coronavirus SARS-CoV-2 is a major ongoing global threat
with huge economic burden. Like all respiratory viruses, SARS-CoV-2 initiates infection in
the upper respiratory tract (URT). Infected individuals are often asymptomatic, yet highly
infectious and readily transmit virus. A therapy that restricts initial replication in the URT has
the potential to prevent progression of severe lower respiratory tract disease as well as
limiting person-to-person transmission. Methods SARS-CoV-2 Victoria/01/2020 was …
with huge economic burden. Like all respiratory viruses, SARS-CoV-2 initiates infection in
the upper respiratory tract (URT). Infected individuals are often asymptomatic, yet highly
infectious and readily transmit virus. A therapy that restricts initial replication in the URT has
the potential to prevent progression of severe lower respiratory tract disease as well as
limiting person-to-person transmission. Methods SARS-CoV-2 Victoria/01/2020 was …
Background
The novel human coronavirus SARS-CoV-2 is a major ongoing global threat with huge economic burden. Like all respiratory viruses, SARS-CoV-2 initiates infection in the upper respiratory tract (URT). Infected individuals are often asymptomatic, yet highly infectious and readily transmit virus. A therapy that restricts initial replication in the URT has the potential to prevent progression of severe lower respiratory tract disease as well as limiting person-to-person transmission.
Methods
SARS-CoV-2 Victoria/01/2020 was passaged in Vero/hSLAM cells and virus titre determined by plaque assay. Challenge virus was delivered by intranasal instillation to female ferrets at 5.0 × 106 pfu/ml. Treatment groups received intranasal INNA-051, developed by Ena Respiratory. SARS-CoV-2 RNA was detected using the 2019-nCoV CDC RUO Kit and QuantStudio™ 7 Flex Real-Time PCR System. Histopathological analysis was performed using cut tissues stained with haematoxylin and eosin (H&E).
Findings
We show that prophylactic intra-nasal administration of the TLR2/6 agonist INNA-051 in a SARS-CoV-2 ferret infection model effectively reduces levels of viral RNA in the nose and throat. After 5 days post-exposure to SARS-CoV-2, INNA-051 significantly reduced virus in throat swabs (p=<0.0001) by up to a 24 fold (96% reduction) and in nasal wash (p=0.0107) up to a 15 fold (93% reduction) in comparison to untreated animals.
Interpretation
The results of our study support clinical development of a therapy based on prophylactic TLR2/6 innate immune activation in the URT, to reduce SARS-CoV-2 transmission and provide protection against COVID-19.
Funding
This work was funded by Ena Respiratory, Melbourne, Australia.
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