Protective immunity induced by an inhaled SARS-CoV-2 subunit vaccine.

Elder E, Bangalore Revanna C, Johansson C, Wallin RPA, Sjödahl J, Winqvist O, Mirazimi A

Vaccine 41 (32) 4743-4751 [2023-07-19; online 2023-06-06]

Targeting the site of infection is a promising strategy for improving vaccine effectivity. To date, licensed COVID-19 vaccines have been administered intramuscularly despite the fact that SARS-CoV-2 is a respiratory virus. Here, we aim to induce local protective mucosal immune responses with an inhaled subunit vaccine candidate, ISR52, based on the SARS-CoV-2 Spike S1 protein. When tested in a lethal challenge hACE2 transgenic SARS-CoV-2 mouse model, intranasal and intratracheal administration of ISR52 provided superior protection against severe infection, compared to the subcutaneous injection of the vaccine. Interestingly for a protein-based vaccine, inhaled ISR52 elicited both CD4 and CD8 T-cell Spike-specific responses that were maintained for at least 6 months in wild-type mice. Induced IgG and IgA responses cross-reacting with several SARS- CoV-2 variants of concern were detected in the lung and in serum and protected animals displayed neutralizing antibodies. Based on our results, we are developing ISR52 as a dry powder formulation for inhalation, that does not require cold-chain distribution or the use of needle administration, for evaluation in a Phase I/II clinical trial.

Category: Vaccines

Type: Journal article

PubMed 37353452

DOI 10.1016/j.vaccine.2023.06.015

Crossref 10.1016/j.vaccine.2023.06.015

pmc: PMC10242152
pii: S0264-410X(23)00684-9

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