There is a bit of work to be done to convince about the efficacy of the Pfizer vaccine and its safety:
The trial was started end of July, therefore the safety data is only that pertaining to immediate adverse effects and no intermediate or long term effects are available. The efficacy data publishes is based on a reduced number of subjects infected after vaccination, 8 , as opposed to 164 who received placebo. The age groups are reported to be 41% aged 55-85, a rather wide spread with no breakdown. The more relevant age breakdown would have been say 55-65 or 70 and 70-85 years because we are not given any more details about the age.
Because there will be many subgroup analyses, this will reduce the power of the statistical significance. Moreover the duration of the protection is unknown because as pointed out the first vaccinations occurred only 20 weeks ago.
So I can see this is very encouraging preliminary data but the rush to license this for emergency use, is now also being used to mean that there will be a mass rollout of the vaccine. Other factors to consider are the difficulties of maintaining a cold chain of minus 70 degrees and also to consider that other vaccine candidates may be more efficient.