Here is what I found about the PFE vaccine: ht

Here is what I found about the PFE vaccine:

https://www.bbc.com/news/health-54873105

"There are still many unanswered questions as this is only interim data.

We do not know if the vaccine stops you spreading the virus or just from developing symptoms. Or if it works equally well in high-risk elderly people.

The biggest question - how long does immunity last - will take months or potentially years to answer.

There are also massive manufacturing and logistical challenges in immunising huge numbers of people, as the vaccine has to be kept in ultra-cold storage at below minus 80C."

I don't think anything in this says this is nothing but great news, but it does show implementing a vaccine is difficult. We also do not need to vaccinate everyone, even a small percentage stops the spread dramatically.

The other detail is that the 90% effective rate will likely become less as trial participants are exposed to covid to really test if the vaccine works. many may not been exposed yet.