
Nasal vaccine against Covid-19 prevents infection in mice - InInteraction
https://medicine.wustl.edu/news/nasal-vaccine-against-covid-19-prevents-infection-in-mice/
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faitswulff
This article on mucosal immunity provides helpful context for intranasal
vaccines:

> Many microbes, including the coronavirus, enter the body through the mucosa
> — wet, squishy tissues that line the nose, mouth, lungs and digestive tract
> — triggering a unique immune response from cells and molecules there.
> Intramuscular vaccines generally do a poor job of eliciting this mucosal
> response, and must instead rely on immune cells mobilized from elsewhere in
> the body flocking to the site of infection.

> Given the potency and rapid spread of the coronavirus, some say it makes
> sense to develop vaccines for the airway as well as the more standard jabs.
> “Knowing how potent mucosal responses can be against a viral pathogen, it
> would be ideal to be thinking about mucosal vaccines,” said Akiko Iwasaki,
> an immunologist at Yale University.

[https://www.nytimes.com/2020/07/14/health/coronavirus-
nasal-...](https://www.nytimes.com/2020/07/14/health/coronavirus-nasal-
vaccines.html)

And here’s one of the first studies using a mouse model (AFAIK) for SARS-CoV-2
if you want to see how that works:
[https://rupress.org/jem/article/217/12/e20201241/151999/Mous...](https://rupress.org/jem/article/217/12/e20201241/151999/Mouse-
model-of-SARS-CoV-2-reveals-inflammatory)

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Duller-Finite
This is an interesting and well-done paper. It is, however, difficult to
evaluate these mouse studies because, unlike human ACE2, mouse ACE2 doesn't
facilitate SARS-CoV-2 cell entry. Therefore, they had to first deliver hACE2
either with an intranasal adenovirus injection, or use transgenic mice
expressing hACE2 in a pattern that does not recapitulate its expression in
humans.

It does seem like they do an especially good job at blocking infections in the
respiratory system, but that's both the system that they primed for infection
and where they provided the ChAd vaccine, so I don't know how fair of a
comparison the intramuscular injection experiments are.

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emmastory
This is really interesting. Obviously evidence in mice is a long way away from
demonstrated safety & efficacy in humans but I'll be curious to see where this
one goes. If non-healthcare-professionals could be trained to administer a
nasal vaccine (the way many non-hcps are able to carry and administer nasal
naloxone in case of opiate overdose), it seems like it might potentially make
vaccine adoption faster or more widespread.

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InInteraction
They evaluated "the protective activity of a chimpanzee adenovirus-vectored
vaccine encoding a pre-fusion stabilized spike protein (ChAd-SARS-CoV-2-S) in
challenge studies with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-
CoV-2) and mice expressing the human angiotensin-converting enzyme 2 receptor"
[https://www.cell.com/cell/fulltext/S0092-8674(20)31068-0](https://www.cell.com/cell/fulltext/S0092-8674\(20\)31068-0)

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jashephe
Just to clarify — the vaccine uses as its backbone a type of adenovirus that
typically infects chimpanzees, modified by the addition of pieces from SARS-
CoV-2, but the experiments testing efficacy are performed in mice
(specifically, a type of mice engineered to express humanized ACE2).

This vaccine has not been tested in chimpanzees (and actually such experiments
would probably be a challenge, since they may have existing immunity to the
backbone adenovirus).

(edit: parent comment initially mentioned experiments in chimpanzees rather
than mice)

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InInteraction
Cell paper:
[https://www.cell.com/cell/fulltext/S0092-8674(20)31068-0](https://www.cell.com/cell/fulltext/S0092-8674\(20\)31068-0)

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user_501238901
I'm very interesting if we switched to using nasal vaccines, would it help
soothe out the rabid anti-vaxxers?

A large part of the movement IMO stems from the fact that subconsciously,
humans tend to associate long sharp needles = pain = bad

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corty
Polio is available as an oral vaccine that used to be widespread in the west.
I still remember demanding a sugarcube with every oral medication after
getting one for the polio vaccination :)

That doesn't seem to stop anti-vaxxers: [https://www.latimes.com/world-
nation/story/2019-09-04/anti-v...](https://www.latimes.com/world-
nation/story/2019-09-04/anti-vaxxers-helping-polio-comeback-pakistan)

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gvjddbnvdrbv
The oral polio vaccine is a live vaccine. It is much more effective than the
injected dead vaccine we now get in the west but it does occasionally cause
polio outbreaks...

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spalt
i want to see the tiny nasal sprayer they used on these mice, must be adorably
cute!

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hanniabu
Is this a general vaccine, or would it only protect you when inhaling through
your nose and neutralizing the virus before it can infect you?

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mike503
This is right out of Contagion! I don’t understand why even I feel like an
injected vaccine vs. a nasal one seems so different. Injected vaccines seem a
bit scary and unknown but I can totally get behind a nasal spray. Very weird.

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cushychicken
Yay!!

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mamon
Anyone here still cares about COVID-19? That's probably the most overhyped
disease of all the time.

