[jyl]

The differences in cold chain requirements are manageable. PFE's vaccine can be directed to larger facilities with special freezers, MRNA's vaccine can be directed to smaller facilities without. AZN's vaccine, which will have data soon, is likely to have less cold chain requirements than either PFE/MRNA. PFE is testing modified formulations to seek more temperature stability.

The duration of protection is unknown. There is fairly good reason to think it is reasonably long, say a year. I don't see where 6 months vs 1 year makes much difference: we'll simply redose as needed.

By spring, potentially everyone in the US who wants to be vaccinated will have been. Then, or starting before then realistically, most remaining social distancing and masking mandates will come off.

The interesting thing is what then happens with the 20-40% of Americans who decline to be vaccinated. They won't be social distancing or masking. A good number of them will already have been infected, but probably not more than 30-40% (estimates are the cumulative infection rate in even the hardest hit states is still less than 30%).

If anti-vaxers are randomly distributed in the general population, they might be few enough to be protected by the immunity level of those around them. If anti-vaxers tend to be concentrated in certain sub populations (and if immunity from recovery or vaccine lasts less than multiple years) that might not be the case, and you may see Covid continue to circulate in the US, using anti-vaxxers as a virus "reservoir".

It'll be interesting to watch. Quite relevant for some investments too. But I look forward to these being just "interesting" rather than something severely affecting our lives and the economy.

Thanks again for volunteering for the trials, redbeard! Go frolic with the sorority girls, you've earned it.