1) This morning, I shared an enthusiastic tweet about Pfizer's interim results with their COVID-19 vaccine. Let me explain here why am I am so enthusiastic, how the road to get this to people might look like and why we still need to control the pandemic NOW. https://twitter.com/florian_krammer/status/1325785189528838147

2) First, the results from the Phase III trial have to be seen in the context of pre-clinical, Phase I and Phase II trials. Preclinically, Pfizer shows the vaccine works in NHPs. Similar vaccines also worked. Also, in early clinical trials their vaccine induced good.....

3)....neutralizing antibody responses (that's what this vaccine does well). Now, in addition to that we get interim efficacy results that are in the 90% range. 90% is pretty good. It might even be higher. Could also be lower. But right now even a vaccine that affords.....

4).....50% protection against severe disease would be positive news. The 90% that they are reporting right now are basically against symptomatic infection. We don't know if you can still get asymptomatically infected. That might matter in the long run to cut down on......

5)....transmission, but is not required to protect at risk individuals against severe disease outcomes. Pfizer has enrolled adults and older adults in their trial. Right now we don't know how efficacy breaks down and if older individuals are as well protected as younger ones....

6)....and that is certainly something that needs to be looked at. I do assume that they will have that data soon. It is also not clear if efficacy goes down over time, we need to look at that too. However, this currently does not curb my enthusiasm.

7) Just the fact that a vaccine that is mostly based on inducing neutralizing antibodies protects from symptomatic infection is fantastic. This might mean, that many other vaccines are likely to work as well. Moderna's vaccine is almost identical. In terms of the immune....

8)....the Novavax vaccine and the Sanofi/GSK vaccine are similar too. And the vectored and inactivated vaccines also induced neutralizing antibodies. So, this is looking good for many of the vaccine candidates. But let's not forget all the people who already have neutralizing....

9)....antibodies from natural infection. All of this needs confirmation, follow up etc. But it is excellent news. Now, how do we move forward. Pfizer says they may file an EUA application in late November (they need to wait for more safety data).

10) Once that is filed, the FDA needs to decide if they grant an EUA and how that will look like. This comes with a problem. If there is an EUA, it would be unethical to not offer the vaccine to the control subjects in the trial. However, doing so would not allow us to.....

11)...gather long-term efficacy data, which is really needed. So, there needs to be some kind of innovative solution. Let's assume that solution is found and the vaccine is licensed/approved in one way or another, say in mid-December. It is likely that in that case very little...

12)....vaccine is initially available and likely only for high risk groups and frontline workers (the National Academy of Sciences has made a plan for that, let's hope its followed). Over time, more and more people will get vaccinated. But this might take months.....

13) So, you have to be patient! But, at least from my point of view, there is now a light at the end of the tunnel. Now, the most important thing while we wait for the vaccine is to keep virus circulation down. It is going massively up in the USA, Canada and Europe and we need...

14)...control it. So, please, while we are waiting: Mask up, physically distance and stick to guidelines and regulations. We have been in this for 10 months, we can do it for another 2-4 to get rid of the problem. Finally....

15) ..if you need more info about vaccines, how they work etc check out the below thread or read this paper.

https://www.nature.com/articles/s41586-020-2798-3

PS: Of course we need to see the data, and of course we need more data. But still, this is just fantastic. https://twitter.com/florian_krammer/status/1310372301314101250?s=20

PPS: I know, people are commenting I am being overly optimistic about this and about timelines. Sometimes, we need some optimism.