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.
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.


PS: Of course we need to see the data, and of course we need more data. But still, this is just fantastic.

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

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More from @florian_krammer

28 Sep
1) SARS-CoV-2 Vaccines - I promised a Tweetorial and here we go. This is going to be long and nerdy. But I'll make sure it is easy to understand. If you want more details, please just read this: nature.com/articles/s4158…
2) I'll try to give an overview of the process, the technologies, correlates of protection, the candidates, how they perform in non-human primates and what we know about their performance in humans so far.
3) Let's start with the process. Developing vaccines usually takes a long time. Usually there is a medical need and some idea of how to design the vaccine, often in an academic lab. Versions of the vaccine are tested in iterative processes, the constructs are optimized....
Read 138 tweets
21 Jul
1) There is a lot of talk about decaying antibodies. I would like to walk you through a few findings about antibodies to SARS-CoV-2 that we put on medRxiv on Friday. Ill do this slowly over the day (while being in nonstop conference calls). But I feel this needs to get out there.
2) So, here is a link to that paper: medrxiv.org/content/10.110…. It is simple and pretty straight forward. Three figures only.
3) Before we start, two things: Acknowledgments and a primer in B-cell biology (a simple one):
Read 33 tweets
26 Jun
1) A lot of people see cases rising while deaths are going down in the US. Somebody who did not like my tweet earlier about the record cases today just pointed that out to me (and also calling me 'dipsh**'). So, I wanna tell a little story about Iran.......
2) There are many reasons why the CFR might go down. We test more, we find more cases. There might be many more younger people infected while older people are more careful and stay at home. Management of COVID-19 got better. There might be several more reasons.....
3) But I would be a little careful. So, Iran experienced a 'second wave' recently. Actually, it wasn't a second wave because the first one never went away. But anyways, after falling case numbers they started to rise again. I was curious about that on Twitter......
Read 6 tweets
6 Jun
1) Nipah virus is another virus to keep an eye on. It doesn't transmit between people well but it can to a certain degree, it has a high CFR and there are regular outbreaks. One vaccines is in clinical trials (funded by CEPI).
2) CEPI is funding clinical trials for vaccines against emerging viruses including Lassa, Nipah Marburg, MERS, Chikungunya, CCHF etc. CEPI is financed by Norway, Japan, Germany, the Gates Foundation and the Wellcome Trust. India is planning to contribute.
3) These CEPI-funded vaccines will potentially avoid future pandemics. The US is not contributing. Maybe tell you representatives that it would be a good idea to change that. cepi.net
Read 4 tweets
25 May
@Docjoshsoc @angie_rasmussen 1) Titer matters. The lower respiratory tract is protected by IgG, the higher your serum IgG, the better. The upper respiratory tract is protected by IgA1, so having mucosal antibodies helps a lot too. High titers matter because they can stop the virus right....
@Docjoshsoc @angie_rasmussen 2) ....when it enters your body. Memory B cells are pretty useful too, but they first need to react and become plasmablasts. For fast acting viruses like influenza this mechanism might contribute to getting less sick, but will likely not prevent you from getting sick.......
@Docjoshsoc @angie_rasmussen 3) ....But since SARS-CoV-2 has a longer incubation period, the plasmablast response (generated from memory B cells) will maybe have a bigger impact. Plasmablasts kick usually in after 5-7 days, which is approximately the mean incubation time of SARS-CoV-2.....
Read 4 tweets
6 May
1) I wanted share some data from a manuscript that just wen online at medrxiv.org/content/10.110…. This was spearheaded by the fantastic Dr. Ania Wajnberg in collaboration with many parts of the Mount Sinai Hospital and Icahn School of Medicine.
2) The data describes PCR and serology findings in the first 1343 plasma donors screened at Mount Sinai. Initially, there were two groups of donors: people who at some point had PCR confirmed COVID19 and people who had suspected COVID19 (but were never PCR confirmed).
3) The majority of these donors were mild cases. Now, almost all PCR-confirmed donors had antibodies, while the majority of the suspected COVID19 individuals did not. This tells us two things: a) the assay works and b) many people who think they had COVID19 might not have had it.
Read 10 tweets

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