5 ms·
A side-by-side comparison of the Pfizer/BioNTech and Moderna vaccines
- hilbert42 6y agoCan someone please explain to me why Pfizer/BioNTech needs a -94 temp to preserve it (i.e.: specifically what is in the vaccine that becomes so biodegradable even at reasonably low temperatures) and similarly why is Moderna one more temperature stable)?
- epmaybe 6y agoLikely their data showed their particular formulation of mRNA and lipid nanoparticles was more stable or “stable enough” at a certain temperature. Otherwise both vaccines are relatively similar so it may really come down to the lipid nanoparticle structures
- hilbert42 6y agoOK, it just seemed to me that was an unusually low temperature needed to maintain longer-term stability given the 5-day shelf life at more normal temperatures. BTW, do you reckon the lipid nanoparticle structures could be damaged by freezing?
- epmaybe 6y agoHonestly I don’t know enough about this haha, if I find more I’ll try and update this comment
- athriren 6y agopfizer did not take the time to check how much warmer the freezers could get without impacting vaccine viability. moderna did. pfizer knew a certain threshold was safe, so they put it on the tin. moderna tested, found their “real” threshold. note pfizer beat moderna to patient arms by about a week or so. both companies made series of these tradeoffs during development due to speed. i think moderna is being slightly more cautious (testing maximum temperature; testing their asymptomatic trial participants, which pfizer did not do) because they got federal dollars and this is their first product out of phase 3. hard to have a bigger rodeo as your first biomedical product.
- hilbert42 6y agoRight, presumably the real/practical limits plus necessary safety margins will fall out after experience is gained.