# Why do COVID vaccines use messenger RNA rather than injecting spike proteins directly? **URL:** \ **Category:** The Quarantine Zone\ **Tags:** covid-quarantine\ **Created:** [April 19, 2021, 4:58am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281 "2021-04-19T04:58:56Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [April 19, 2021, 4:58am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/1 "2021-04-19T04:58:56Z")
It seems a little Rube Goldberg to induce the body to create spike proteins with mRNA, then have the immune system react to those newly-created spike proteins. Why not grow the spike proteins in a big vat (or in an animal or in culture) then inject the spike proteins into the body directly? I can think of a number of reasons why mRNA might be better. But I’m not a biologist so I don’t know the hurdles in manufacturing and delivering spike proteins. Disclaimer: Get vaccinated! I got my 2nd shot yesterday! ---
**Author:** ![FigNorton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fignorton/32/5619_2.png) [@FigNorton](https://boards.straightdope.com/u/FigNorton)\ **Post date:** [April 19, 2021, 5:30am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/2 "2021-04-19T05:30:18Z")
In a way, they are harder to produce because you have to make the proteins, collect them then inject them whereas the new vaccines let your body be the factory and delivery system. See, it’s not anymore Rube Goldberg because you still make the protein by inducing something to make it. Protein vaccine manufacture would induce perhaps yeast cells to produce spike and then you collect that for injection. What you’re talking about is very much one of the tools in vaccine production. > **[What are protein subunit vaccines and how could they be used against COVID-19?](https://www.gavi.org/vaccineswork/what-are-protein-subunit-vaccines-and-how-could-they-be-used-against-covid-19)** > > Protein subunit vaccines use fragments of protein from the disease-causing virus to trigger protective immunity against it. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [April 19, 2021, 6:02am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/3 "2021-04-19T06:02:56Z")
> [@Measure\_for\_Measure](#): > > Why not grow the spike proteins in a big vat (or in an animal or in culture) then inject the spike proteins into the body directly? Problems include allergic reaction to the host (egg, horse, bacteria or yeast), mutation (same as COVID mutation in humans), and simply, getting replication of a larger fragment is more difficult. However, (not knowing any better), I think that _this time_, we got mRNA vaccines because there is a recently developed method of generating prototype mRNA vaccines, which is much faster and cheaper and generated a lot of different prototypes, with trials starting in ~ March last year (???) instead of March _next_ year. ---
**Author:** ![FigNorton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fignorton/32/5619_2.png) [@FigNorton](https://boards.straightdope.com/u/FigNorton)\ **Post date:** [April 19, 2021, 6:10am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/4 "2021-04-19T06:10:11Z")
> [@Melbourne](#): > > However, (not knowing any better), I think that _this time_ , we got mRNA vaccines because there is a recently developed method of generating prototype mRNA vaccines, which is much faster and cheaper and generated a lot of different prototypes, with trials starting in ~ March last year (???) instead of March _next_ year. This mRNA technology was an awesome answer in search of its problem. It has a bunch of research lines with a some failures notably on cancer treatment. It’s my understanding that vaccines are a better fit for the tech because of the lower dosages needed. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [April 19, 2021, 9:18am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/5 "2021-04-19T09:18:35Z")
As far as I know, mRNA technology was always built with an eye towards its use in vaccines, in part because of how much more quickly said vaccines could be made, and how they avoided problems that can arise in other methods. Here is the SciShow video on this: [![](https://img.youtube.com/vi/XPeeCyJReZw/maxresdefault.jpg "Why It Actually Took 50 Years to Make COVID mRNA Vaccines") ](https://www.youtube.com/watch?v=XPeeCyJReZw) As for the question in the OP: having the host make the proteins is just a lot more efficient than making them and having to keep them around, and getting them into where they need to be. You can do so by putting the RNA code in a virus instead, but that’s more complicated than just being able to use mRNA directly in something the cells will consume. There’s no danger of the immune system learning to attack the vaccine vector. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [April 19, 2021, 3:15pm UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/6 "2021-04-19T15:15:43Z")
One mRNA can be run through the protein manufacturing system (the ribosomes) multiple times, so it’s not like you’d just replace one mRNA strand with one spike protein. Not that I think that was a factor in the OPs thinking. ---
**Author:** ![FigNorton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fignorton/32/5619_2.png) [@FigNorton](https://boards.straightdope.com/u/FigNorton)\ **Post date:** [April 19, 2021, 4:35pm UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/7 "2021-04-19T16:35:18Z")
> [@BigT](#): > > As far as I know, mRNA technology was always built with an eye towards its use in vaccines Maybe but if you read some pre-2020 articles, many of them are describing trials using mRNA as a “vaccine” against cancer. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [April 19, 2021, 8:51pm UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/8 "2021-04-19T20:51:22Z")
There were something like 30 or more covid vaccines under development when i first started following it. They included mRNA (Moderna, Pfizer), viral vector (AZ, J&J, Sputnik), killed whole virus (Sinovac) and some that were just the spike protein with an adjuvant. The ones we are using are the ones that made it to market and through testing first. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [April 21, 2021, 7:53am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/9 "2021-04-21T07:53:11Z")
We don’t presently have any local production of mRNA vaccines in Aus, and the local vaccine company said that it would take the best part of a year to build a mRNA production facility. _Somebody_ had already built production facilities, so they must have had _something_ in mind. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [June 27, 2021, 2:11am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/10 "2021-06-27T02:11:09Z")
update: Novavax, a traditional vaccine that is basically the spike protein plus an adjuvant, did really well in clinical trials, and has been licensed by the Serum Institute of India, which hopes to produce 2B doses. It’s stable at cool temps, and doesn’t need to be frozen. I believe they’ve applied for FDA approval, although the FDA may not feel like it needs more emergency approvals, and might make them wait for full ordinary approval before it can be sold in the US > **[The mRNA Vaccines Are Extraordinary, but Novavax Is Even Better](https://www.theatlantic.com/health/archive/2021/06/novavax-now-best-covid-19-vaccine/619276/)** > > Persistent hype around mRNA vaccine technology is now distracting us from other ways to end the pandemic. > **[Novavax COVID-19 vaccine](https://en.wikipedia.org/wiki/Novavax_COVID-19_vaccine)** > > Pages for logged out editors learn more > > > The Novavax COVID-19 vaccine, sold under the brand names Nuvaxovid and Covovax, among others, is a subunit COVID-19 vaccine developed by Novavax and the Coalition for Epidemic Preparedness Innovations (CEPI). Full results from Nuvaxovid's pivotal phase III trial were published in December 2021. > The Novavax COVID‑19 vaccine is indicated for active immunization to prevent COVID‑19 caused by SARS-CoV-2. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [June 28, 2021, 4:00am UTC](https://boards.straightdope.com/t/why-do-covid-vaccines-use-messenger-rna-rather-than-injecting-spike-proteins-directly/940281/11 "2021-06-28T04:00:19Z")
mRNA vaccines were under development for Ebola, and making some progress, but the Ebola epidemic blew over and the vaccine development got shelved. When Zika hit the scene, the technology development was dusted off and continued, I think. Then I guess that blew over too and the development was shelved. So when Covid-19 hit, there was already some progress in making mRNA vaccines, so they just picked that up where it left off.