4 ms·

"Others are probing SARS-CoV-2 itself. In a preprint published this month, researchers tinkered with the virus to learn how much it has to change to evade the a

"Others are probing SARS-CoV-2 itself. In a preprint published this month, researchers tinkered with the virus to learn how much it has to change to evade the antibodies generated in vaccine recipients and recovered patients. They found that it took 20 changes to the spike protein to escape current antibody responses almost completely." It's great that we have the genetic engineering tech to do these experiments and identify new risks while there is still time to be proactive about them. My best guess for the preprint is [0]. Note that the virus they were using is a vesicular stomatitis virus modified so its replication depends on ACE-2 receptor binding via the SARS-CoV-2 spike (S) protein, a copy of which was spliced in. They're not working with SARS-CoV-2 itself. This technically would count as "gain of function research", as recently popularized, and is an example of how the approach can help us identify and respond to emerging threats. It sounds like we may end up handling Covid exactly like the flu, with annual vaccines tailored to whatever strains seem most dangerous for the upcoming year. [0] https://www.biorxiv.org/content/10.1101/2020.07.21.214759v1.full https://www.biorxiv.org/content/10.1101/2020.07.21.214759v1....

dmix 5y ago
I’m curious how long it would take to adapt the mRNA vaccines to the new ones, if there was two changes. I’m assuming it’d have to reach quite a wide infection rate for them to tag a particular variant + development/manufacturing time. The other question that comes to mind is if they can package two different variants into one or would they just mix the two and keep building on top of existing ones? Unless the other ones get completely replaced.
- mlyle 5y ago
  Making the mRNA in volume is the easy part. They can turn that around extremely quickly-- large prototype quantities in days, and begin ramping sharply in weeks. The hard part is the formulation chemistry and microfluidics and nanoparticles, which don't change based upon variant mix. Of course, the really hard part is approval, but we feel we understand influenza viruses and vaccines enough to have developed an expedited approval process each year. We should be able to do the same for COVID-19.
mlyle 5y ago
> It sounds like we may end up handling Covid exactly like the flu, with annual vaccines tailored to whatever strains seem most dangerous for the upcoming year. Or, perhaps, we'll do better. People who had SARS-CoV-1 and subsequently were vaccinated against SARS-COV-2 have been shown to have potent immune responses not just against all known variants of SARS-CoV-2 but also the entire genus of Sarbecoviruses. This implies a pan-coronavirus vaccine is at least possible.
- Engineering-MD 5y ago
  Do you have a reference? I would be interested sin reading the paper
  - mlyle 5y ago
    Sure! https://www.nejm.org/doi/full/10.1056/NEJMoa2108453 https://www.nejm.org/doi/full/10.1056/NEJMoa2108453 Pan-Sarbecovirus Neutralizing Antibodies in BNT162b2-Immunized SARS-CoV-1 Survivors, Tan et al, NEJM 2021 Aug 18.

dmix 5y ago

I’m curious how long it would take to adapt the mRNA vaccines to the new ones, if there was two changes. I’m assuming it’d have to reach quite a wide infection rate for them to tag a particular variant + development/manufacturing time. The other question that comes to mind is if they can package two different variants into one or would they just mix the two and keep building on top of existing ones? Unless the other ones get completely replaced.

mlyle 5y ago
Making the mRNA in volume is the easy part. They can turn that around extremely quickly-- large prototype quantities in days, and begin ramping sharply in weeks. The hard part is the formulation chemistry and microfluidics and nanoparticles, which don't change based upon variant mix. Of course, the really hard part is approval, but we feel we understand influenza viruses and vaccines enough to have developed an expedited approval process each year. We should be able to do the same for COVID-19.

mlyle 5y ago

> It sounds like we may end up handling Covid exactly like the flu, with annual vaccines tailored to whatever strains seem most dangerous for the upcoming year. Or, perhaps, we'll do better. People who had SARS-CoV-1 and subsequently were vaccinated against SARS-COV-2 have been shown to have potent immune responses not just against all known variants of SARS-CoV-2 but also the entire genus of Sarbecoviruses. This implies a pan-coronavirus vaccine is at least possible.

Engineering-MD 5y ago
Do you have a reference? I would be interested sin reading the paper
- mlyle 5y ago
  Sure! https://www.nejm.org/doi/full/10.1056/NEJMoa2108453 https://www.nejm.org/doi/full/10.1056/NEJMoa2108453 Pan-Sarbecovirus Neutralizing Antibodies in BNT162b2-Immunized SARS-CoV-1 Survivors, Tan et al, NEJM 2021 Aug 18.