Tolerability and immunogenicity of an intranasally-administered adenovirus-vectored COVID-19 vaccine: An open-label partially-randomised ascending dose phase I trial.

BACKGROUND

Intranasal vaccination may induce protective local and systemic immune responses against respiratory pathogens. A number of intranasal SARS-CoV-2 vaccine candidates have achieved protection in pre-clinical challenge models, including ChAdOx1 nCoV-19 (AZD1222, University of Oxford / AstraZeneca).

METHODS

We performed a single-centre open-label Phase I clinical trial of intranasal vaccination with ChAdOx1 nCoV-19 in healthy adults, using the existing formulation produced for intramuscular administration. Thirty SARS-CoV-2 vaccine-naïve participants were allocated to receive 5 × 10

FINDINGS

Reactogenicity was mild or moderate. Antigen-specific mucosal antibody responses to intranasal vaccination were detectable in a minority of participants, rarely exceeding levels seen after SARS-CoV-2 infection. Systemic responses to intranasal vaccination were typically weaker than after intramuscular vaccination with ChAdOx1 nCoV-19. Antigen-specific mucosal antibody was detectable in participants who received an intramuscular mRNA vaccine after intranasal vaccination. Seven participants developed symptomatic SARS-CoV-2 infection.

INTERPRETATION

This formulation of intranasal ChAdOx1 nCoV-19 showed an acceptable tolerability profile but induced neither a consistent mucosal antibody response nor a strong systemic response.

FUNDING

AstraZeneca.

Informations de copyright

Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.

Déclaration de conflit d'intérêts

Declaration of interests Oxford University has entered into a partnership with AstraZeneca to develop ChAdOx1 nCoV-19. AJR and KE may receive royalties arising from the University of Oxford/AstraZeneca COVID-19 vaccine. TL is named as an inventor on a patent application covering this SARS-CoV-2 vaccine and was previously a consultant to Vaccitech on an unrelated project. AVSH is a cofounder of and former consultant to Vaccitech is named as an inventor on a patent covering design and use of ChAdOx1-vectored vaccines (PCT/GB2012/000467), and may receive royalties arising for the University of Oxford/AstraZeneca COVID-19 vaccine. DW, EJK, TV, and JAG are current employees of AstraZeneca and hold or may hold AstraZeneca stock. ADD reports grants and personal fees from AstraZeneca outside of the submitted work, is a named inventor on patent applications relating the chimpanzee adenovirus platform technology and manufacturing, and may receive royalties arising from the University of Oxford/AstraZeneca COVID-19 vaccine. All other authors declare no competing interests.