A study published in ACS Nano describes a vaccine platform that uses cell-derived extracellular vesicles (EVs) displaying inverted hemagglutinins (HAs) on their surface. The goal is a mucosal vaccine that protects the respiratory tract and helps prevent virus spread during epidemics or pandemics.
With the inverted arrangement the HA stalk becomes more exposed to the immune system while the variable HA head is less visible. The stalk contains conserved structures shared by many influenza strains, so targeting it can produce broader protection than strain-specific vaccines.
In mice, multiple HA-EV vaccines given intranasally elicited cross-reactive antibodies to HA stalks, robust virus-specific cellular immune responses and a balanced Th1/Th2 profile. Intranasal immunization with these vaccines provided complete protection against lethal heterosubtypic challenges with H7N9 and H5N1 reassortants. The authors note that EVs are a biocompatible delivery platform and that more mucosal vaccine strategies are needed.
Difficult words
- extracellular vesicle — a small membrane particle released by cellsextracellular vesicles
- hemagglutinin — a viral surface protein on influenza viruseshemagglutinins
- invert — to put something in the opposite positioninverted
- stalk — a supporting or connecting part of a proteinstalks
- cross-reactive — able to react with different but related targets
- mucosal — relating to the moist lining of body passages
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Would you prefer a mucosal vaccine given through the nose rather than an injection? Why or why not?
- What are the possible advantages of targeting the HA stalk instead of the HA head in influenza vaccines?
- What practical challenges might scientists face when developing more mucosal vaccine strategies?
Related articles
Study: Year‑round RSV Immunization Could Reduce Big Outbreaks
A study in Science Advances finds that offering RSV immunizations year‑round would lower the chance of large seasonal outbreaks in the United States. Researchers compared spread in cities and rural areas and tested seasonal versus year‑round schedules.
Targeting inflammation as a way to treat depression
A federally funded review and meta-analysis found that anti-inflammatory treatments reduced depressive symptoms and eased anhedonia in people with depression who had high inflammation. The drugs were not FDA-approved for depression and would be used off-label.
Emory study: 2023–24 COVID vaccine gives lasting antibodies
Emory University measured antibody responses in 24 people after the 2023–24 monovalent vaccine targeting Omicron XBB.1.5. The study found long-lasting antibodies, cross-reactive protection with the ancestral WA1 strain, and a 2.8-fold boost from immune imprinting.
Antibody and EGFR–STAT1 pathway point to new fibrosis treatments
Researchers at Yale found a human antibody that blocks epiregulin and lowers fibrosis markers. They also show EGFR activates STAT1 in fibroblasts, suggesting two treatment paths: block epiregulin or target the EGFR–STAT1 pathway.