: How a nasal vaccine could reduce the risk of COVID infections — and new variants

by | Mar 17, 2023 | Stock Market

For many, one of the defining moments of the COVID-19 pandemic was when they learned that the mRNA vaccines developed by Moderna
and by BioNTech
and Pfizer
worked.  Then came the first wave of breakthrough infections in mid-2021 and the gradual understanding, both in scientific circles and among the general public, that the vaccines are far less powerful protectors against infection than we initially thought — even though they do a pretty great job at preventing severe disease.

One way to address the infection paradox is by improving mucosal immunity, either by an intranasal vaccine — one that is inhaled through the nose — or other methods. Mucosal immunity aims to offer protection at the site of infection — in this case, the mucous membranes of the nose — along with the systemic immunity offered by an injected vaccine. Some countries are already using vaccines that target mucosal immunity, including China, which began rolling out an inhaled COVID vaccine developed by CanSino Biologics
last fall, and India, which made Bharat Biotech’s nose drops available in January as a primary or booster dose. Iran and Russia reportedly have nasal vaccines, as well. No intranasal vaccines have been authorized or approved in the U.S., although there are several in development, including Blue Lake Biotechnology’s experimental vaccine, which produced promising data from a Phase 1 clinical trial, and Codegenix’s candidate, which is in Phase 3 clinical trials. Both companies are privately held.  MarketWatch talked to Dr. Joachim Hombach, executive secretary of the World Health Organization’s Strategic Advisory Group of Experts on Immunization, to talk about intranasal vaccines and what they could bring to the table three years into the pandemic.  MarketWatch: What are the benefits of a nasal vaccine for COVID? Hombach: An intranasal administration may be more convenient than an injection and parenteral [non-oral] administration. That’s number one. Number two is that we expect from a nasal vaccine — because the antigen is administered to the mucosa — that we induce mucosal immunity, and our expectation from mucosal immunity is that it does a better job in terms of preventing infection, which in turn would reduce transmission intensity.  MarketWatch: What are the challenges in developing a nasal vaccine? Hombach: We have a couple of mucosal vaccines, which actually also include those that are already administered, like oral polio [vaccine]. But they’re not targeted directly at the respiratory tract. The best known intranasal vaccine is an influenza vaccine — [AstraZeneca’s
] FluMist — which has relatively limited indication but shows that it works in kids better than a classical vaccine, but not in adults or older adults. The challenge of developing a nasal vaccine is essentially how to evaluate it. You’re assessing the impact on transmission. You can assess infection reduction, yes, but you will also want to really quantify the impact on transmission, and this takes more complicated studies.  The other problem that we have is on the immunological side. Specifically, in the context of COVID, we have a fair understanding of the relationship between protection against more severe disease and the level of neutralizing antibodies in the bloodstream. This is also the way now the vaccines are being licensed. They’re being licensed on the basis of immu …

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