This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

peer-reviewed publication

trusted source

proofread

Next generation COVID-19 immunization strategies could deliver vaccine directly to the respiratory tract

vaccine
Credit: CC0 Public Domain

The global COVID-19 vaccination campaign saved an estimated 20 million lives. However, while current COVID-19 vaccines provide protection against developing severe disease, they do little to prevent infection and transmission.

Findings published in the journal Nature by physician-scientists at Beth Israel Deaconess Medical Center (BIDMC) and colleagues suggest that it may be possible to improve protection against COVID-19 by delivering the vaccine directly to the —the primary site of entry in SARS-CoV-2 infection.

"The failure of the current generation of SARS-CoV-2 vaccines delivered by the intramuscular (IM) route to block infection likely relates to their inability to induce robust mucosal immune responses at the portal of entry," said corresponding author Dan H. Barouch, MD, Ph.D., director of the Center for Vaccine and Virology Research at BIDMC.

"In this study, we demonstrated that novel immunization strategies can markedly increase mucosal immunity in non-human primates and improve protective efficacy against a mucosal virus challenge."

Barouch and colleagues primed 40 adult with the Ad26 COVID-19 vaccine (Janssen/Johnson & Johnson) administered intramuscularly (IM)—like a shot in the arm adults typically receive. Approximately a year later, the animals received a booster.

Three groups received either a dose of the Ad26 vaccine via the IM route, the intranasal (IN) route (delivered via ) or the intratracheal (IT) route (delivered by nebulizer or inhaler). A fourth group received a dose of the bivalent mRNA (Pfizer-BioNTech) by the IN route. A sham group received no boosters.

When the macaques were later challenged with a high dose of the virus, the investigators sampled the animals' blood, nasal, and lung fluids to monitor their immune responses. They found that the Ad26 booster administered via the IT route provided near complete protection against a high-dose SARS-CoV-2 challenge and induced greater mucosal immunity than it did via the IN or IM route.

In contrast, mRNA IN boosting proved ineffective, suggesting that improved formulations will likely be required for effective mucosal delivery of mRNA vaccines.

"Taken together, these data demonstrate that novel immunization strategies can markedly increase mucosal immunity in and improve protective efficacy against a mucosal virus challenge," said Barouch. "These data suggest the feasibility of developing vaccines that block respiratory viral infections."

More information: McMahan, K. et al, Mucosal boosting enhances vaccine protection against SARS-CoV-2 in macaques, Nature (2023). DOI: 10.1038/s41586-023-06951-3 www.nature.com/articles/s41586-023-06951-3

Journal information: Nature
Citation: Next generation COVID-19 immunization strategies could deliver vaccine directly to the respiratory tract (2023, December 14) retrieved 21 June 2024 from https://medicalxpress.com/news/2023-12-generation-covid-immunization-strategies-vaccine.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

Single-shot COVID-19 vaccine protects non-human primates

105 shares

Feedback to editors