Do you know why Moderna and Pfizer decided to develop vaccine injections instead of nasal sprays?

I expect it’s because they were prioritizing speed of making it available, and maximum effectiveness, and wanted to avoid adding a complicating factor (i.e. is the spray delivery method reducing effectiveness?).

Well, injection is a tried and true method, and by the way, have you read the list on the CDC site about who should not use the nasal spray method?
That is a lot of people to exclude from a vaccine during a pandemic.

Sprays don’t work nearly as well, and there is more wastage.

That’s why regular flu vaccines are injections, not sprays. Not effective.

Nasal vaccines are usually live attenuated virus and Pfizer and Moderna are mRNA. Is nasal a possibility for mRNA? That’s interesting.

The mRNA was attractive because it would help move along other research besides covid related health issues and mRNA does not need to be grown, so it can be produced quickly as long as the right equipment is available.

Moreover, the flu nasal vaccine is not recommended for people over 50. I don’t remember why.

That should give you a start for research though.

@JLeslie No, the mRNA is only for injection.

@Caravanfan I guess that answers the question then regarding why Moderna and Pfizer didn’t pursue a nasal vaccine.

IMHO The muscle is more acceptable. Not possibly clogged with mucus. Just saying.
Yu’re more assured of delivering te precise dose. Should the recipient sneeze… not good.

Why take a chance of permanently damaging the sense of smell. The vaccines may contain substances that damage nerves in the nose needed for smell (like the cold remedy Zicam).

@Caravanfan Either engage or don’t. BUT please do not brush aside a serious question with a well-known fact.

@JLeslie You said: “I guess that answers the question then regarding why Moderna and Pfizer didn’t pursue a nasal vaccine.”, knowing full well it didn’t. I will never do that.

@JLeslie The following article details how the use of mTNA vaccines in the form of a nasal spray is being investigated.

See
https://news.cision.com/chalmers/r/nasal-spray-could-deliver-a-future-mrna-vaccine-against-covid-19,c3179185

However, that still leaves open my question. You are absolutely correct about the nasal version of the flu vaccine not being recommended for adults over 50 – see
https://pubmed.ncbi.nlm.nih.gov/8525683/. The publication does not give a reason for it, but I assume the study enrollment did not include enough people over 50.

One interesting facet of the flu vaccine is that it works in either injection form or nasal spray form. There does not seem to be any reason why the injected COVID-19 vaccine would not produce antibodies in the nose and throat.

@elbanditoroso I would tend to assume the same thing. However, we seem to know that the flu vaccine works just as well in either form. See
https://www.webmd.com/children/vaccines/flu-shot-nasal-spray#1

@ragingloli An off-the-cuff answer that does not stand scrutiny and research.

“Tried-and-true”: Here is evidence that shows the nasal spray works just as well.
See
https://www.webmd.com/children/vaccines/flu-shot-nasal-spray#1

Yes, I have read the list of people who should not take the nasal vaccine. Do you know why adults 50 and older are excluded?

@Zaku Thanks for a good answer. We really do not know the reason why both Pfizer and Moderna decided to proceed in the direction of the shot, only to come back and say that the shot may not produce sufficient antibodies in the nose and throat. We do know that the flu shot works in the nose and throat.

@si3tech Good reasons. However, you would think the same rationales would apply to flu vaccines. Spoiler alert: They do not. For instance, see
https://www.webmd.com/children/vaccines/flu-shot-nasal-spray#1

@gondwanalon Very good point. However, since the shot will not allow vaccinated people to go about without masks, choices should be given.

One thing to consider is right now it’s safer for the medical care workers to give a shot, because the person receiving the vaccine can be masked.

I didn’t see in your link WHY over 50 are not recommended to take flu nasal vaccine. I tried to quickly google about it and everything is just the recommendation and not an explanation for why. I don’t know if it’s that older people don’t absorb the vaccine well, if absorption is even an issue, I’m just making up stuff, or if they have more negative reactions, less efficacy, I don’t know why.

I guess the next step would be to google the actual research when it was coming to market or maybe the manufacturer insert actually has over 50 results. I’ll have to try later today.

Since over 50 is the primary target group to stop severe illness and death, then any indication that a nasal spray might be a waste of time for that age group for the initial roll out would mean it makes sense not to pursue that route a year ago. It might be something for the future though.

And, @Caravanfan did not brush aside your question. He believed that mRNA was not a candidate, he was answering my question.

Remember guys, punctuation notwithstanding, @crazyguy doesn’t actually want answers, he wants support of his presented premises.
He is, after all, here to keep us informed.

Hahahahaha.

@JLeslie Thanks for your comment. Yes, I realized @Caravanfan was answering your question. However, in your infinite kindness, you have paraphrased his answer. What he said was “No, the mRNA is only for injection.” You paraphrased his answer to “He believed that mRNA was not a candidate”. I would suggest to you that there is a difference in the two statements. One cites the current level of knowledge, while your paraphrase seems to indicate that mRNA cannot be given nasally. @Caravanfan‘s answer is factual but does not further the discussion.

As I have indicated on this thread it is possible to create a vaccine that employs mRNA and can be utilized as a nasal spray. See https://bmcbiotechnol.biomedcentral.com/articles/10.1186/1472-6750-10-77

I do NOT know why nasal sprays are not recommended for people over 50.

@canidmajor Actually, I would welcome well-reasoned refutations of my premises.

@crazyguy, actually, you tend not to, unless they are presented by users you already like. You have been here long enough for us to recognize patterns in your behavior.
But that’s OK, you just be you.
Have fun.

@crazyguy I just interpret @Caravanfan’s answer differently than you, but I obviously can’t answer for him what he meant. My impression was he believed the science was the mRNA cannot be given through nasal vaccine. If he is incorrect that’s not such a big deal, I’m not sure why you are so put off by it. You posted information to the contrary and we all learn from being on the Q.

@JLeslie I agree it is not a big deal. I think we all could benefit by researching any relevant subject, and by avoiding pat answers based on no hard knowledge.

I fully understand that research takes time that we do not have as a rule. I am in the rather fortunate position of being retired, and have the luxury of time. I try to use it as best as I know how. If I disagree with any poster it is because my research leads me there.

Probably more cost effective in the long run, as well as more effective results.

@crazyguy flu vaccine may be effective for younger folk, but my doc said that for people over 65 the flu shot is better protection

The flu shot for seniors is a higher dose. I think it’s recommended for 65 and older. I don’t know if it’s available every year. I would assume so.

@JLeslie The point I am trying to make is that if the flu vaccine can be administered as a nasal spray, I am certain that the covid vaccine can also be delivered the same way.

@elbanditoroso So, for older people, flu antibodies can reach the nose and throat; but, for some strange reason, the antibodies produced by the covid vaccine cannot.

@kritiper I agree there would be less waste with an injection versus a nasal spray. However, if an injection cannot protect the population as a whole, it may be worthwhile incurring the waste.

@crazyguy – I am not a doctor or an immunologist. I’ll bet you aren’t either.

But I do know how to read.

@elbanditoroso No, I am not a doctor. However, I am infinitely curious. I have not seen any study indicating that covid antibodies behave differently from flu antibodies and cannot reach the nose and throat. Have you?

The fastest approach was intramuscular injections. We are in the middle of a pandemic. Fast matters.

There is an intranasal vaccine being developed in Hong Kong.