eric topol's latest substack on nasal vaccines at: erictopol@substack.com
excerpts:
This piece accompanied a new study in experimental models showing the potential for nasal vaccines to patch up our “leaky” intramuscular vaccines which, after the virus’s evolution to Omicron, have exhibited markedly reduced suppression of infections and transmission. The results of the nasally administered vaccine highlighted that shots don’t provide tissue-level mucosal immunity, b ut an adenovirus vector nasal vaccine induced marked increases in IgA levels and T-cell immune response in the lung (via bronchoalveolar lavage).
Those results were reinforced by many other experimental studies, including Akiko’s group at Yale with the “prime and spike” strategy of a nasal vaccine after 2 mRNA shots that led to strong mucosal immunity (CD8+, CD4+ cells, memory B and T cells, IgA levels), significantly lower viral loads, and less disease and fatality.
Another pivotal point is the potential for mucosal immunity to protect against the sarbecovirus family, enabling variant-proof protection, instead of the current approach of coming up with update booster shots that are unable to keep up with the virus’s persistent evolution (i.e. variant chasing). The virus gets into our body via our upper airway lining (mucosa), so defending this site of entry should, as experimental studies have shown, provide broad protection against SARS-CoV-2 variants. We asserted: “The objective of breaking the chain of transmission at the individual and population level will put us in a far better position to achieve containment of the virus, no less reducing the toll of sickness and long COVID-19.”
Shots provide only moderate (30-40% reduction) and brief (<6-8 weeks) protection from infections. - - i didn't realize that it was that bad.
The big gap in our armamentarium is an easy to administer, durable, potent, variant-proof, safe nasal vaccine that blocks infections and transmission. Even if it was necessary to take it every 3 or 4 months, the protection it would provide would help our exit ramp from Covid concerns, further moving us back towards pre-pandemic life.
A frequent question that I get asked: “When may we see a Covid nasal vaccine in the United States?” Maybe never. But I think there’s increasing likelihood that it may happen before the end of 2024. Yes, that’s too long a wait given its “urgent need” and the promising results emanating from so many US academic labs over the past couple of years. But remember Covid will be with us for many years to come, so a highly effective and safe nasal vaccine will be most welcome whenever it’s ready. |
