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Florian Krammer Profile
Florian Krammer

@florian_krammer

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Viruses, viruses, viruses and vaccines. V5=3xancestral+1x bivalent+1xXBB Professor at the Department of Microbiology Icahn School of Medicine at Mount Sinai

New York, NY
Joined February 2016
Don't wanna be here? Send us removal request.
@florian_krammer
Florian Krammer
3 years
There is a janitor on our floor who I often talk to, a very nice and friendly guy. For months now I was trying to convince him to get vaccinated. Today he told me he just got the Moderna shot.😀👍👍👍
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@florian_krammer
Florian Krammer
4 years
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:
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@florian_krammer
Florian Krammer
2 years
1) My gut feeling from hearing of Omicron cases in Botswana, ex-Malawi, ex-Egypt (2 now it seems) and in South Africa is, that the variant was flying under the radar in undersequenced countries for some time until Botswana and South Africa detected it and sounded the alarm.
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@florian_krammer
Florian Krammer
4 years
1) I am getting a little annoyed at people responding to my tweets saying 'why do you even believe the Chinese numbers' and 'China was hiding this' etc. There is something we all need to keep in mind: China bought us time and we wasted it.
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@florian_krammer
Florian Krammer
3 years
Toni Fauci just showed @POTUS a SARS-CoV-2 virion schematic that I made a year ago and shared with NIAID. Awesome! I love it!
@POTUS
President Biden
3 years
When I said I would listen to the scientists as president, I meant it.
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@florian_krammer
Florian Krammer
3 years
@NICKIMINAJ Chlamydia is a more likely explanation - and may also explain why the relationship ended. While there is unfortunately no licensed vaccine against chlamydia yet, there are vaccines against other STDs, like HBV and HPV. Maybe spread that information instead of misinformation.
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@florian_krammer
Florian Krammer
3 years
If you raise a glass of champagne tonight (or diet coke or whatever) to welcome 2021, also raise it to celebrate science.
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@florian_krammer
Florian Krammer
3 years
No words needed. That's what vaccines do.
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@florian_krammer
Florian Krammer
4 years
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.
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@florian_krammer
Florian Krammer
3 years
So, can we please now have CDC COVID-19 press briefings back? Maybe every Monday and Friday? Maybe led by someone we trust, e.g. Dr. Anne Schuchat? CDC is supposed to lead us through this, we'd like to have you back!
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@florian_krammer
Florian Krammer
2 years
Liebe Medien: Kann man bitte aufhören den Impfstoff von Novavax als Totimpfstoff zu bezeichnen? Es ist ein rekombinanter Proteinimpfstoff. Dafür wird das Spike Protein mithilfe von Baculoviren in Mottenzellen hergestellt und dann mit Matrix-M Adjuvant (ein Saponin) formuliert.
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@florian_krammer
Florian Krammer
3 years
I am getting my second shot today in the COVID-19 trial I am enrolled in. I sincerely hope I am not in the placebo control group.
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@florian_krammer
Florian Krammer
4 years
My lab with and without immigrants.
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@florian_krammer
Florian Krammer
4 years
I am about to hire a postdoc from Spain who is specialized in vaccine production and a postdoc from Japan who is specialized in mucosal immunity to virus infections. I might not be able to hire them if this is signed. Both would have worked on SARS-CoV-2 and influenza virus.
@nprpolitics
NPR Politics
4 years
President Trump is expected to sign an order to suspend H-1B, L-1 and other temporary work visas through the end of the year. The new order is expected to come with broad exceptions:
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@florian_krammer
Florian Krammer
3 years
We had to wait 12 months for this.
@BNOFeed
BNO News
3 years
BREAKING: U.S. CDC expected to sign order requiring masks on all public transportation - Reuters
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@florian_krammer
Florian Krammer
1 year
@Cobratate @GretaThunberg Buddy, that wasn't good enough. You lost.
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@florian_krammer
Florian Krammer
4 years
OK guys. China controlled it. South Korea is controlling it. Singapore is controlling it. Taiwan is controlling it. Hong Kong is controlling it. Can we please motivate leaders in our Western countries to do the same? We can learn from Asia and we can do it too!!!
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@florian_krammer
Florian Krammer
3 years
1) So, this morning I promised a little tweetorial about variants and here we go. This will be from a vaccine/antibody point of view only, I won't comment on how infectious they are or if they are more pathogenic (I'll leave that to Boris Johnson 😉).
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@florian_krammer
Florian Krammer
3 years
Negative thought of the day: I think we will be as unprepared for the next pandemic as we were for this one. Maybe I am just too negative but I don't see anybody stepping up their game. I hope I am wrong.
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@florian_krammer
Florian Krammer
4 years
That's leadership. Anthony Fauci is a national treasure.
@aphillippy
Adam Phillippy
4 years
Throwback to 5 years ago when Tony Fauci, at 74 yo, was suiting up to treat an Ebola patient himself because he "wanted to show his staff that he wouldn't ask them to do anything he wouldn't do himself". This is what leadership looks like.
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@florian_krammer
Florian Krammer
4 years
After getting informed about the risks I signed up today for a Phase III trial with a SARS-CoV-2 mRNA vaccine. I am happy to contribute some data points to a hopefully safe and efficacious vaccine!
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@florian_krammer
Florian Krammer
4 years
There is a reason for canceling public gatherings. In a pandemic, don't be Philadelphia (held a parade in 1918 when cases started to come up, downplayed cases), be St. Louis (canceled gatherings). More here: @mlipsitch
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@florian_krammer
Florian Krammer
3 years
Pennsylvania saved our a** but Georgia is saving our soul.
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@florian_krammer
Florian Krammer
3 years
1) If we want to generate difficult viral escape mutants in the lab (e.g. for epitope mapping), we subject the virus to low antibody pressure and then slowly move up. A little bit like after one vaccine dose. I think it would be good to give the second dose as soon as possible.
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@florian_krammer
Florian Krammer
2 years
PS: We are all tired. The health care workers are tired, the researchers are tired, everybody is tired of the pandemic. We all want our lives back. Unfortunately, the virus doesn't care. And we can only get through this together.
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@florian_krammer
Florian Krammer
3 years
OK, I am retweeting this, so nobody misunderstands it. Barely any SARS-CoV-2 infections anymore in Israel. Vaccines work.
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@florian_krammer
Florian Krammer
2 years
1) What do I think about Omicron now that some neutralization data is available? My impression hasn't change. We seem to see a drastic reduction in neutralizing activity, far more than with previous variants. Little activity was left in vaccinated individuals and it is likely....
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@florian_krammer
Florian Krammer
3 years
If you, out of curiosity, get an antibody test after the second dose of vaccine, and it is negative, don't freak out. The test was probably done against nucleoprotein, not spike protein. And there is no nucleoprotein in the US/EU vaccines. You will only make antispike antibodies.
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@florian_krammer
Florian Krammer
3 years
Dear world, we have a second vaccine!
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@florian_krammer
Florian Krammer
4 years
2) It is easier to believe numbers from the Chinese government than in no numbers at all. I am sick of people blaming the Chinese. Chinese health care workers are heroes and many of them payed with their lives for responding fast to this.
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@florian_krammer
Florian Krammer
4 years
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.......
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@florian_krammer
Florian Krammer
2 years
I think I speak for almost everybody here: Omicron sucks. I don't like it.
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@florian_krammer
Florian Krammer
3 years
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.
@florian_krammer
Florian Krammer
3 years
Dear World. We have a vaccine! Best news since January 10.
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@florian_krammer
Florian Krammer
3 years
More than 1000 people per day are dying in the US right now of COVID-19. It is a long time till January 20. Its 74 days. And much longer until measures taken then will show an effect. We are talking about >74,000 deaths. We need to act now.
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@florian_krammer
Florian Krammer
4 years
OK, so now we have avian flu in the Netherlands (in birds, not humans) and a mink variant of SARS-CoV-2 in Denmark in humans (consequences of adaptive mink mutations unknown). Great week so far.
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@florian_krammer
Florian Krammer
3 years
Here we go
@BNOFeed
BNO News
3 years
NEW: CDC study finds Pfizer/Moderna vaccines are not only effective against symptoms, but also 90% effective against coronavirus infection
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@florian_krammer
Florian Krammer
3 years
There seems to be a big overlap between the people who say the virus is harmless and the people who say the vaccine is dangerous.
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@florian_krammer
Florian Krammer
2 years
2) However, the fact that European countries only detected it in travelers after South Africa and others warned about it, probably means that many cases so far went undetected. It also tells us a lot about genomic surveillance in some high income countries.
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@florian_krammer
Florian Krammer
4 years
This is unbelievable. How could this go so wrong?
@Craig_A_Spencer
Craig Spencer MD MPH
4 years
The US just reported it’s highest #COVID19 daily case count ever. This isn’t just more testing. This is just pure failure.
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@florian_krammer
Florian Krammer
3 years
I want to sum up the last two days in vaccine news: We got two more vaccines that work. I know, the variants complicate things, but this is still EXCELLENT news. Looking forward to J&Js prime-boost data.
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@florian_krammer
Florian Krammer
4 years
Good news. Rhesus macaques seem to be immune to re-challenge with SARS-CoV-2. This suggests that we are also immune once we clear the infection (serology in humans points in same direction). Not sure how long immunity lasts but likely for months or years.
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@florian_krammer
Florian Krammer
3 years
I think there is an important point that many people are missing: While we are getting this virus under control, it is unlikely that it completely disappears. That means, everybody who is susceptible will get infected at some point in time. Unless you are vaccinated.
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@florian_krammer
Florian Krammer
4 years
3) Millions of Chinese people were and are under a lockdown that bough us time. Would any of our Western countries have done the same? Did we contain this? China uses lockdowns and great technology to manage this. We can't even test large numbers of people.
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@florian_krammer
Florian Krammer
2 years
1) Boston University researches have made a SARS-CoV-2 virus that has the spike of Omicron BA.1 and the remaining genome of the ancestral SARS-CoV-2. Now they got in trouble because this research was funded by the US government (NIH) but they did not ask the NIH...
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@florian_krammer
Florian Krammer
2 years
Kann man Merkel nicht als Österreichische Bundeskanzlerin gewinnen? Teilzeit wuerd ausreichen.
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@florian_krammer
Florian Krammer
3 years
1) The biggest worry for vaccines about the new UK variant is the N501Y mutation in the receptor binding domain. This is also a mutation that appears when SARS-CoV-2 is mouse adapted. A paper looking at that found....
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@florian_krammer
Florian Krammer
2 years
Das hat mich jetzt grad zum Weinen gebracht. Es tut mir so leid.
@SvenMobrep
Sven Knobloch
2 years
#Sachsen #Erzgebirgskreis Corona-Inzidenz 2006,2. Es ist zum verzweifeln. via @MDRAktuell
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@florian_krammer
Florian Krammer
4 years
LOL, yes, IgG has a half-life of 21 days.....
@EricTopol
Eric Topol
4 years
The patient had a whopping (8g) dose of a #SARSCoV2 neutralizing IgG antibody cocktail. Then they detected antibodies. You must be kidding me, Dr. Conley?
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@florian_krammer
Florian Krammer
2 years
8) A shoutout and big thank you to @Tuliodna and many other researchers from South Africa and Botswana for sharing sequences and information in real time!
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@florian_krammer
Florian Krammer
4 years
I cannot disagree more. We need to go the proper route. Safety and efficacy need to be proven, the FDA will license vaccines (or not) once that data is in. While I am very much for cutting unnecessary corners, there can be no cutting corners with safety and efficacy testing.
@StevenSalzberg1
Steven Salzberg 💙💛
4 years
We don't have to wait months for phase 3 trials of #COVID19 vaccines to finish. We have safe vaccines already, and millions of people (including me) would take them now if permitted. Just do it
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@florian_krammer
Florian Krammer
3 years
Its amazing how many professionals call it 'COVID-19 infection'. COVID-19 is the disease, not the virus. COVID-19 is caused by SARS-CoV-2 infections.
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@florian_krammer
Florian Krammer
4 years
Italy just reported 1492 new cases and 133 new deaths. Can we please take this serious. Actions that look ridiculous today will look like the most reasonable thing in 3 weeks, keep that in mind.
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@florian_krammer
Florian Krammer
4 years
Yes, the WHO made mistakes. PHEIC declared too late, pandemic declared too late, wrong messaging on masks and other things. But compared to the US government they behaved like a poster child. Sorry, I am not trying to politicize here but I am allergic to lies.
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@florian_krammer
Florian Krammer
2 years
The city of Vienna in Austria has now booked a vaccination appointment for everybody not vaccinated. They are informed via a letter and asked to cancel if they don't go to the appointment. Not a lot of pressure, but may get some more people vaccinated.
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@florian_krammer
Florian Krammer
3 years
1) Finally this it out. It took a few years of my life to get this into clinical trials (with the help of many others). A first step towards the clinical development of universal influenza virus vaccines. With Adolfo Garcia-Sastre, Peter Palese.
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@florian_krammer
Florian Krammer
4 years
By the way: The person who developed the antibody test in my lab is Pakistani. The person who moved it to the clinical lab is Austrian. The people who purify the necessary antigens are Indian, Singaporean, Austrian, Pakistani and US-American.
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@florian_krammer
Florian Krammer
3 years
I know, a lot of people feel like celebrating right now. But please, keep you mask on, keep distance and stay away from crowds. There is a lot of virus around, we have so many cases. Stay safe!!!!
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@florian_krammer
Florian Krammer
4 years
Of course. That's what many of us virologists have been saying since the first report of this.....
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@florian_krammer
Florian Krammer
3 years
If the North Koreans find out that it takes that long for the National Guard to be at the Capitol, we are in trouble.
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@florian_krammer
Florian Krammer
2 years
@RickABright I lost faith in our ability to stop pandemics and pandemic waves. Especially in 'developed' countries. We can do it from a technology point of view, but I think policymakers, political leaders and society as a whole have failed over and over again.
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@florian_krammer
Florian Krammer
3 years
I think it will be very important to communicate to the population that these vaccines have more reactogenicity (injection site pain, transient fatigue, headache, elev temp) than most other licensed vaccines. Not dangerous but unpleasant. People need to know what to expect.
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@florian_krammer
Florian Krammer
4 years
Vaccines should be ready when they are found to be safe and efficient. Not when its favorable for elections.
@saraecook
Sara Cook
4 years
CDC Director Redfield sent a letter to governors "urgently" requesting them to expedite applications for vaccine distribution facilities and waive requirements that would prevent them "from becoming fully operational" by November 1, @CBSNews confirms. First reported by @mcclatchy
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@florian_krammer
Florian Krammer
4 years
757 people died. Today. In New York City. People, stay at home!
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@florian_krammer
Florian Krammer
3 years
Have fun! I am happy for you.
@ChampChong
Alen Champ
3 years
This is happening in my city here in Australia right now in December 2020. Post-covid festivals are here. We haven’t had a case of covid in the community for over 8 months. Life is back to normal thanks to everyone doing the right thing! 👍
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@florian_krammer
Florian Krammer
3 years
@BreyJabba @NateSilver538 I teach a class on emerging pathogens. And I run a lab studying viruses. But thanks for enlightening me.
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@florian_krammer
Florian Krammer
1 year
@short_tymer I hope both got prophylactic rabies treatment after that incident.
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@florian_krammer
Florian Krammer
2 years
@Reevellp @yousitonmyspot Nobody seems to be drinking their tea.
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@florian_krammer
Florian Krammer
4 years
1) OK, so here is my team member of the day, Fatima Amanat @FatimaAmanat . She started to work on SARS-CoV-2 right away in January when the sequence came out and made a lot of the constructs we are sending out to you guys. And she got the first RBD and spike ELISAs ...
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@florian_krammer
Florian Krammer
1 year
Maybe 2023 is going to be the year when we start to take influenza, RSV and co more serious instead of taking SARS-CoV-2 less serious.
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@florian_krammer
Florian Krammer
3 years
For everybody worried that RNA vaccines are now tested for the first time in humans. That is actually not the case. See list below. It is true that there is little long term safety data. But its not true that there is no long term safety data.
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Florian Krammer
3 years
It is very important for people to get their 2nd shot of vaccine (except for J&J, or if you had confirmed COVID-19 before, then one is enough). I find this trend that people only get one shot very alarming. Immunity in this case is incomplete and may not last as long.
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@florian_krammer
Florian Krammer
4 years
4) So, please stop pointing fingers and motivate your own governments to act. These comments are wrong and not constructive, especially not at this point in time. I will block anybody who makes them.
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@florian_krammer
Florian Krammer
2 years
Samples for the first 3 Omicron cases were from Nov 11 in Botswana, the sample in Hong Kong (ex-SA) was from Nov 13. Cases have now been detected in many European countries. It is very likely that the variant is in the US. I am actually surprised nobody reported one yet today.
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@florian_krammer
Florian Krammer
2 years
A little 2 year anniversary tweet.
@florian_krammer
Florian Krammer
4 years
This is not good:
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@florian_krammer
Florian Krammer
2 years
The disappearance of the B/Yamagata/16/88-like influenza B virus lineage teaches us a very important lesson: Influenza B virus can be eradicated from the human population.
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@florian_krammer
Florian Krammer
3 years
2)....I finally received my first dose of BNT162b2, Pfizer's mRNA vaccine. I am very happy about that. Now I am translating and expressing😉. I am looking forward to being protected and I'll get my 2nd dose on schedule in 3 weeks.
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@florian_krammer
Florian Krammer
3 years
1) There are a lot of questions about how fully vaccinated individuals should behave. I don't have good solutions either, but I have some thoughts. First of all, we are seeing more and more data about how well vaccination works in a real live setting. There are recent studies...
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@florian_krammer
Florian Krammer
4 years
As I explained when this happened with AZ: This is the normal process. This doesn't mean the illness is related to the vaccine. But these things need to get investigated by an independent committee. Happens in many Phase III trials.
@rickberke
Rick Berke
4 years
EXCLUSIVE: Johnson & Johnson #COVID19 vaccine study paused due to unexplained illness in participant via @statnews @matthewherper
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@florian_krammer
Florian Krammer
3 years
Saw a dead bat in Central Park today while running. If you see a live, dead or injured bat, do not touch it. They harbor rabies which is arguably the most deadly virus that exists for humans. Just leave them alone.
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@florian_krammer
Florian Krammer
4 years
THREAD. 1) I am going to put up my slides here from an overview presentation I gave at Sinai. I hope you find it helpful.
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@florian_krammer
Florian Krammer
4 years
Just a few thoughts about the Moderna paper from today. The results look very very similar to the results Pfizer published as preprint a few days ago, maybe a little more reactogenicity. Both vaccines seem to be promising (like a number of others as well). I am optimistic.
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@florian_krammer
Florian Krammer
3 years
My commute today.
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@florian_krammer
Florian Krammer
2 years
If pacifism means that mad dictators are allowed to invade sovereign nations and have their soldiers kill and rape civilians, then please count me out.
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@florian_krammer
Florian Krammer
2 years
7) But there are a lot of unknowns, and many 'scariants' have come and gone. I assume we will have a much better idea about the actual risk in 2-3 weeks. We need to stay calm and do our work.
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@florian_krammer
Florian Krammer
4 years
Here are some potentially good news. The ratio of deaths versus infections is much lower in South Korea (0.53%) than in other countries, likely because they test so much. This might change but I think it gives a more real idea about the CFR.
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@florian_krammer
Florian Krammer
4 years
Not sure what Russia is up to but I certainly would not take a vaccine that hasn't been tested in Phase III. Nobody knows if its safe or if it works. They are putting HCWs and their population at risk.
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@florian_krammer
Florian Krammer
1 year
My friendly neighbour gave me a booklet which was provided to UK and US soldiers who went to Austria after WWII as a short intro to the country. Its an amazing read (thanks Andy!!!). It also contains this gem. The last sentence explains a lot of the current problems.
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@florian_krammer
Florian Krammer
2 years
It is important to keep in mind that the invasion of Ukraine is the doing of a mad dictator and not the Russian people.
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@florian_krammer
Florian Krammer
4 years
Guys, when you see the numbers going up in the next few days, keep in mind that it will take time until countermeasures and social distancing show an effect due to the long incubation time of the virus. Stay home, stay save!
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@florian_krammer
Florian Krammer
4 years
I think it is official now. FDA gave our two-step ELISA an emergency use authorization! Great collaboration between Mount Sinai's clinical lab (Drs. Carlos Cordon-Cardo, Adolfo Firpo, Rao Damodara Mendu and Jeffrey Jhang) and my team!
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@florian_krammer
Florian Krammer
2 years
3) The mutations in Omicron which seem to wipe out the majority of neutralizing antibody epitopes are very worrisome. Combined with the apparent fitness of the virus, this could be a problem. There is now a lot to do to get a better idea of the risk this virus variant poses.
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@florian_krammer
Florian Krammer
2 years
Schutzmaßnahmen aufheben und Impfpflicht aussetzen während die Infektionen auf einem Allzeit-Hoch sind. Herr Rauch @johannes_rauch , macht das Sinn?
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@florian_krammer
Florian Krammer
3 years
1) The low efficacy of the Novavax vaccine candidate against the B.1.351 is concerning. However, the data is also reassuring in many ways. First, the vaccine itself worked very well against the 'old' SARS-CoV-2 variants and the B.1.1.7 (UK) variant. Also, the vaccine...
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@florian_krammer
Florian Krammer
4 years
We have drafted a detailed protocol for antigen expression and ELISA set-up for COVID19 serology. Download it her: . This can be used to set up ELISAs in research labs but also clinical labs. The vectors for expression can be requested from my lab.
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@florian_krammer
Florian Krammer
4 years
Very wise decision: Pulling out of the WHO during a pandemic. [sarcasm off] I hope we join again in 2021.
@BNOFeed
BNO News
4 years
BREAKING: U.S. has officially withdrawn from the World Health Organization, U.S. Senator Menendez says
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