This is very good news indeed, and the *potential* implications go well beyond the @pfizer #COVID19 vaccine.

While we just have the press release, it's worth reviewing what this *could* mean for the pandemic and beyond. A thread. 1/

@BioNTech_Group https://twitter.com/ashishkjha/status/1325770292199907330

First, it shows vaccines *can* prevent COVID illness in humans, and it validates the spike protein target. We didn't know these things before today, and it's good news for all #COVID19 vaccines in development. 1/

Second, the early efficacy is quite high, although it may wane over time. We can't say anything about duration of protection yet, but it helps to start from a high level of efficacy. Higher efficacy reduces the uptake needed to significantly dampen virus transmission. 2/

Third, this is the first time an mRNA vaccine has demonstrated efficacy in a human Phase 3 efficacy trial. That has significant ramifications for the mRNA platform as well as immunization more broadly. Much more will be written on this in the future. 3/

Fourth, this could have major implications for emerging infectious diseases (EID) preparedness, given the "plug-and-play" nature of mRNA vaccines and emphasis on chemistry over biology in manufacturing. Important note: there is no guarantee mRNA will work against all targets. 4/

Having cited all of these *potential* benefits, many questions remain unanswered: duration of protection, efficacy against severe disease, protection of older adults, long-term safety, etc. We'll learn much more when the data is published and with long-term follow up. 5/

The bottom line is that this is very good news for COVID vaccine development and the world's pandemic response. There are sure to be surprises and setbacks in our vaccine efforts in the future, but we can all cheer today's news. 6/

Disclosures: I don't have a financial interest in any company developing a COVID vaccine. Takeda has partnered with Novavax to manufacture and distribute their vaccine in Japan, and with Moderna to distribute their vaccine in Japan on a one-time basis. 7/