In today's superspreader/overdispersion piece by @zeynep (the best, comprehensive one on this topic to date), she also reviews how important these cheap, frequent, rapid turnaround tests can prevent such spread theatlantic.com/health/archive…@TheAtlantic
When you combine this w/ @ScienceMagazine yesterday on PCR tests (CT, cycle threshold) you realize that the testing we have today, mostly detecting infections but not infectious, are way off the mark.
We should all have had the home rapid tests months ago!
We're now passing very sad milestone of 1 Million deaths from COVID in the world. Its worth thinking about what is working effectively internationally, and what isn’t, esp in terms of global cooperation and systems. Here are some thoughts on that: 1/x
.@WHO and most countries in world have joined together to jointly plan and buy vaccine via the COVID-19 Vaccines Global Access [COVAX] Facility. There has never been an effort like this before. This has potential to do enormous good. pulitzercenter.org/reporting/who-… 2/x
If it succeeds as planned, it'll accelerate vaccine development + allow access to vaccine to high income + low income countries. But it'll require substantial fundraising. Unfortunately neither China nor US are partners in it, which is leadership failure on both their parts. 3/x
150M is substantial number of Ag tests. Their arrival will be very welcome. Important to plan for how these and other Ag tests coming on line should best be used. It’s a very big supply of testing, but not enough to meet range of potential public and institutional needs. 3/x
I feel it is important to call out misunderstandings about what 'herd immunity' means. It is clear from this little thread that @TheEliKlein has no idea. I'm not trying to be mean, just to correct a decidedly... odd take. I hope he'll end up understanding it a little better 1/n
First, I am going to ditch the phrase 'herd immunity' because bluntly it annoys me and it understandably makes folks indignant about being compared to cattle. We will use population immunity instead 2/n
There are lots of very clever (too clever by half imo) takes on how few people you might actually need to have immunity in order to exclude the virus from a community. That's what the term means by the way, not just *slowing* it 3/n
It's pouring on now:
"#Trump's Taxes Show He's a National Security Threat
What trade-offs would a president with this level of indebtedness be willing to make to save face?"
(His financial needs mean he will sell out the nation motif)
"It was the moment when Donald #Trump's 'Art of the Deal' fabulism, billionaire tycoon bluster and populist standard-bearing for forgotten Americans was revealed to be what it always looked like: a sham."
(Emperor has no clothes motif) MORE cnn.com/2020/09/28/pol…
"But the eyes that really matter are the federal and state tax authorities charged with reviewing whether or not Trump and the Trump Organization broke tax laws.
And whether the President could possibly go to prison."
(The lock-him-up motif)
- How is vaccine efficacy calculated?
- Distinguishing between infection, disease, & severe disease.
- Measuring reduced infectiousness.
- Vaccine efficacy vs. effectiveness!
2) Vaccine efficacy (VE) measures the relative reduction in infection/disease for the vaccinated arm versus the unvaccinated arm. A perfect vaccine would eliminate risk entirely, so VE = 1 or 100%. This can be calculated from the risk ratio, incidence rate ratio, or hazard ratio.
3) Vaccine efficacy of 50% roughly means you have a 50% reduced risk of becoming sick compared to an otherwise similar unvaccinated person. Or you have a 50% chance of becoming sick given that you were exposed to enough infectious virus to make an unvaccinated person sick.
“Last week we reached an important milestone in which, @WHO issued the first Emergency Use Listing for a quality antigen based rapid diagnostic test, and we expect other rapid tests to follow. ”, says @DrTedros at #covid19 presser.
@WHO@DrTedros Good news: 120 million of these tests will be made available to low- and middle-income countries, to "enable the expansion of testing, particularly in hard to reach areas that do not have lab facilities or enough trained health workers to carry out PCR tests”, says @DrTedros.
@WHO@DrTedros These tests are cheaper ("priced at a maximum of 5 US dollars per unit”) and faster (15-30 minutes) than PCR, says @DrTedros. "The quicker #COVID19 can be diagnosed, the quicker action can be taken to treat and isolate those with a virus and trace their contacts."
NEW: The loss of credibility in CDC has sent morale to all-time low. “The worst is the silence,” one scientist said. “You can’t explain what’s going on, correct mistakes, clarify things quickly before they spin up and out of control.” Me + @joelachenbachwapo.st/30hUXkC
@JoelAchenbach 1/ Career staff at CDC remain proud of the expertise, talent and professionalism that the agency can bring to bear in a crisis. But they see the agency’s situation clearly.
@JoelAchenbach 2/The CDC has endured false accusations and interference by Trump administration political appointees, leading to loss of institutional credibility at a time when the nation desperately needs to know whom to trust.
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....
Some thoughts on wastewater (sewage) testing...
Of most benefit when used in an area with no known cases. Lets us look for a signal that virus is somewhere in that region. Pop-up testing may then be deployed to get a better idea of the situation
Methods/usefulness still being evaluated.
What does a positive mean? How often are false negative/positives likely? Which PCR-based tests are best? What processes in place to confirm wastewater positive result & what response will that trigger if confirmed?
💩Do all agree?
Full spectrum of responses to wastewater testing, from exuberance to dismissal. I think time and continued refinement of the methods will tell which was the best position. As with everything in this pandemic, we're learning many new things as we go.
Many important things happened related to COVID in the US this past week. Here are some of the good and some of the not-good developments, and their implications. First, here are some of the good: 1/x
J&J started large (60,000 person) phase 3 trial of its vaccine. Its 1 dose only, which distinguishes it. Safety + efficacy results by early 2021. Storage requirements (-20 C) are compatible w/ standard vaccine distribution approaches. Very good. 2/x fiercebiotech.com/biotech/j-j-st…
This is more forward progress from Op Ward speed collaboration btwn gov & vaccine makers. Potentially invaluable for fight against COVID. Important to let trials and regulatory process proceed safely, so people don’t lose confidence in what could be most helpful tools. 3/x
Tomorrow's @thesundaytimes. Data is clear. Political & societal decisions on what to do extraordinary difficult. Very little room for a middle way that keeps things open & also prevents transmission, illness & COVID/NonCOVID deaths. Needs a national debate thetimes.co.uk/article/no-fud…
Not possible keep society & economy open as now & suppress transmission,prevent hospitalisations & deaths COVID & non-COVID & pressure on NHS. Anyone suggesting there are easy political decisions or possible to open society & economy & control epidemic is doing a great disservice
Need urgent national debate & political decisions to be made & fairly binary choice:Open up society & economy but accept higher transmission,hospitalisations & deaths vs further restrictions implemented now, reduce transmission, keep schools open & reduce COVID illnesses & deaths
Why did we write a letter to a vaccine company about the need to complete its Phase 3 trial and provide compelling proof of its safety and efficacy?
An explanatory thread 1/
Normally this process would be straightforward. But these are anything but normal times. @Pfizer has its 1st interim analysis next week of 32 events (which include mild infections, such as a sore throat or headache +PCR virus). It has its own Data & Safety Monitoring Board. 2/
That DSMB has only 5 members. It could decide to stop the trial due to a predefined efficacy threshold (≥ 26 events w/placebo). It reports to Pfizer. The Pfizer CEO has said @FaceTheNation that its trial will have enough #COVID19 cases to apply for approval by late October. 3/
Q: What about people who get a seasonal flu vaccine and still get sick with flu symptoms?
A: There are several reasons why someone might get flu symptoms, even after being vaccinated against flu...👇🏽
One reason is that you can become ill from other viruses besides flu- e.g. rhinoviruses, which are associated w/ common cold, cause symptoms similar to flu, & also spread and cause illness during #flu season. The flu vaccine only protects against flu, not other illnesses. (2/?)
A second explanation is that you can be exposed to #flu viruses shortly before getting vaccinated, or in the 2 week period afterwards that it takes to develop immune protection. This exposure may mean you become ill with flu before protection from vaccination takes effect. (3/?)
Covid Epi Weekly: People are tired of fighting the virus, but the virus isn’t tired of infecting people
As parts of Europe and the US show, turn your back on Covid and it will come back to bite you. Cases trending up again in many states, likely to hit 50,000/day in October. 1/9
2/9 Trends in positivity are getting harder to track. Per Covid Tracking Project, only 9 states documented to follow best practice of reporting antigen & PCR tests separately. (States should also report unduplicated people positive/tested, crossreferencing the two types of test.)
3/9 What starts in the young doesn’t stay in the young. @MMWR reports young adult infections were followed a week or two later by infections in people over 60. We are all connected. The sooner we recognize that, the sooner we can move forward more safely. bit.ly/369yrOu