There's been a lot of new information regarding the Pfizer vaccine and the others:

1. It starts exhibiting actual immunity faster than expected - apparently within a couple of days.
2. Transportation at -90C is proving to be difficult, but not impossible. The UK is also looking forward to the Moderna vaccine, which can be transported/stored at about -20C, which is much more do-able.
3. The Astra-Zenaca vaccine is apparently stable/storable at much closer to room temperature, but there've been some anomalies reported in their Phase III testing. Plus, their reported efficacy as reported at around 70%, but that's an average between the whole-dose and half-dose initial dose. Given that the ordinary flu vaccine is around 70%, it looks like it may be very useful, especially if they get the dosage right.