Love this writeup - very helpful! One question I had - is it generally an "easy" process to figure out which viral protein (the Spike protein in this case) to encode for?
This is from Lawrence: "Yes and no. I think people knew that the spike protein is a prominent feature of the viral envelope that our cells can recognize in an infection (and people who were infected produced antibodies against the spike protein). But often there are many possible protein targets on the surface of the virus that you could choose and it's not always clear which one is the best or, furthermore, even if you've chosen the "best" target (that is, an antigen), whether you can stimulate a robust enough response to that target to actually be of use when you are infected.
With conventional vaccines, you're showing the "entire virus" (or large chunks of it at least), so you know you're flashing images of the entire "culprit". By targeting the spike protein, you're just like showing pictures of, say, the distinctive tattoo of the culprint and hoping that that will be enough to recognize the culprit
In some ways that could be better because of the specificity but hypothetically, you might still need the photo of the entire body to contextualize the tattoo.
To answer your question more directly, yes in the sense that the spike protein was the most "obvious" target but not in the sense that it's not a sure thing that getting the immune response to recognize the spike protein (or at least recognize it strongly enough) would be enough to mount an immune response to actual virus...that was the big fear scientists had when going into the phase 3 trials (where you finally had enough participants to see an appreciable number of them get covid in both the control and treatment groups)"
Hey Charles! I'm definitely not qualified to give a real answer here, but what I do know is:
1 - probably hard to answer in general, since this is the first approved mRNA vaccine
2 - coronaviruses have existed before (SARS and MERS, as well as the common cold).
It looks from this link from April (https://www.livescience.com/coronavirus-spike-protein-structure.html) that people already knew that spike proteins were a key part in coronavirus infections, so I would guess that the key was that they just needed to identify the one in covid.
Will the mRNA-based vaccines work in animals? Besides bats, mink, and domesticated cats and dogs, here's the latest species to be diagnosed with COVID19:
Still unclear if the current mRNA will work in animals, but COVID19 vaccines are being explored for mink - "Not only are mink the only nonhuman animal known to become severely ill and die from the virus, they are the only animal known to have caught the virus from humans and then passed it back."
Love this writeup - very helpful! One question I had - is it generally an "easy" process to figure out which viral protein (the Spike protein in this case) to encode for?
This is from Lawrence: "Yes and no. I think people knew that the spike protein is a prominent feature of the viral envelope that our cells can recognize in an infection (and people who were infected produced antibodies against the spike protein). But often there are many possible protein targets on the surface of the virus that you could choose and it's not always clear which one is the best or, furthermore, even if you've chosen the "best" target (that is, an antigen), whether you can stimulate a robust enough response to that target to actually be of use when you are infected.
With conventional vaccines, you're showing the "entire virus" (or large chunks of it at least), so you know you're flashing images of the entire "culprit". By targeting the spike protein, you're just like showing pictures of, say, the distinctive tattoo of the culprint and hoping that that will be enough to recognize the culprit
In some ways that could be better because of the specificity but hypothetically, you might still need the photo of the entire body to contextualize the tattoo.
To answer your question more directly, yes in the sense that the spike protein was the most "obvious" target but not in the sense that it's not a sure thing that getting the immune response to recognize the spike protein (or at least recognize it strongly enough) would be enough to mount an immune response to actual virus...that was the big fear scientists had when going into the phase 3 trials (where you finally had enough participants to see an appreciable number of them get covid in both the control and treatment groups)"
Hey Charles! I'm definitely not qualified to give a real answer here, but what I do know is:
1 - probably hard to answer in general, since this is the first approved mRNA vaccine
2 - coronaviruses have existed before (SARS and MERS, as well as the common cold).
It looks from this link from April (https://www.livescience.com/coronavirus-spike-protein-structure.html) that people already knew that spike proteins were a key part in coronavirus infections, so I would guess that the key was that they just needed to identify the one in covid.
Thank you for these 'take-away' articles.
Will the mRNA-based vaccines work in animals? Besides bats, mink, and domesticated cats and dogs, here's the latest species to be diagnosed with COVID19:
https://www.nytimes.com/2020/12/11/science/covid-snow-leopards.html
Curious about this issue given that cross-species transmission started this whole pandemic.
Many thanks - Melanie
Still unclear if the current mRNA will work in animals, but COVID19 vaccines are being explored for mink - "Not only are mink the only nonhuman animal known to become severely ill and die from the virus, they are the only animal known to have caught the virus from humans and then passed it back."
This is an emerging story of the virus:
https://www.nytimes.com/2020/12/23/science/covid-mink-animals.html?referrer=masthead