This is interesting and I wish that he went into some more detail on how they spray dry without destroying protein activity. I actually have some first-hand experience trying to develop a spray drying method for antibody solutions for immunotherapy products. Ultimately, I left that company, but the real big problem was that most antibodies can't survive the temperature needed for spray drying. For this reason, usually freeze drying is used instead (there are even techniques for spray freeze drying). They claim that the process inactivates viral capsids, but preserves antibody activity and having worked with both in the past, that seems like a bold claim.
Lemmy note: I had originally made this comment from my account on Beehaw, but it doesn't seem to have federated over. So, if you see this twice, my apologies.