Results for “plasma” 42 found
Incentives for Organ Donation
Lottery tickets for vaccination seems to have been reasonably succesful. What else could we use incentives for? Al Roth sends us to kidney surgeon Arthur Matas’s argument for testing incentives for organ donation:
A regulated system of incentives for donation could provide a sizable increase in the number of kidneys available for transplant. Yet incentives for kidney donation are illegal in the US.
…Initially, the concept of incentives for living donation can be unsettling (some have said “repugnant”4). Yet ethicists worldwide have argued that there is no ethical reason to prohibit incentives. And studies show that the public is in favor of incentives. Additionally, dialysis is more expensive than transplant; a regulated system of incentives would be cost saving to the health care system.We accept kidney donation. Any successful argument against incentivized donation must be able to differentiate it from our currently accepted conventional donation. Notably, incentives are legal for plasma, sperm, and egg donation or surrogate motherhood, and certainly there are risks involved with egg donation and surrogate motherhood. Gill and Sade5 argue that the only difference between donating and selling is monetary self-interest, and monetary self-interest alone does not warrant legal prohibition.
It is time to move past the feelings that incentives are wrong to the reality that as a result of a potentially preventable shortage of organs, patients on the waiting list are dying or becoming too sick to transplant….It is time for professional societies and patient groups to advocate for changing the law to allow trials of incentives for donation.
See many previous posts at MR on organ donation and blood donation.
Mormon markets in everything?
Or is it thwarted Mormon markets in everything?:
Brigham Young University-Idaho is warning students that if they try to get the novel coronavirus, they will be suspended from school.
BYU-Idaho issued a statement Monday, saying administrators are “deeply troubled” about students intentionally exposing themselves or others to COVID-19, with the hope of getting the disease so they can be paid for plasma that contains COVID-19 antibodies.
Here is the full story, via John Chilton.
Decentralized serological testing?
I would like to know more, but here is one new paper on the topic, by Lottie Brown, et.al.:
Serological testing is emerging as a powerful tool to progress our understanding of COVID-19 exposure, transmission and immune response. Large-scale testing is limited by the need for in-person blood collection by staff trained in venepuncture. Capillary blood self-sampling and postage to laboratories for analysis could provide a reliable alternative. Two-hundred and nine matched venous and capillary blood samples were obtained from thirty nine participants and analysed using a COVID-19 IgG ELISA to detect antibodies against SARS-CoV-2. Thirty seven out of thirty eight participants were able to self-collect an adequate sample of capillary blood (≥50 μl). Using plasma from venous blood collected in lithium heparin as the reference standard, matched capillary blood samples, collected in lithium heparin-treated tubes and on filter paper as dried blood spots, achieved a Cohen′s kappa coefficient of >0.88 (near-perfect agreement). Storage of capillary blood at room temperature for up to 7 days post sampling did not affect concordance. Our results indicate that capillary blood self-sampling is a reliable and feasible alternative to venepuncture for serological assessment in COVID-19.
Via Alan Goldhammer.
Friday assorted links
1. PBA cards, and implicit trades with police.
2. Australia: “Lawyers and civil liberty groups have expressed concerns about the way a pregnant woman was arrested at her home in Ballarat for allegedly encouraging people to take part in an anti-lockdown rally.” I guess she didn’t have a good enough PBA card.
3. The football culture that is Fargo. 10,000 at an indoors game? And is a two-puffin photo twice as good as a one-puffin photo?
5. New data on the Russian vaccine.
Tuesday assorted links
1. 538 on why NBA scoring has been so high.
3. Derek Lowe on convalescent plasma.
4. “Most of the time, most people do not know (precisely) what they are talking about.”
6. Valuable perspective on Covid-19 reinfection, not yet the worry it might seem to be. This associated, linked Science piece is excellent not only for its content, but also for showing how reasoning ought to be done.
7. Update on the FDA and test regulations, recommended for those who care.
Our regulatory state is failing us, antibodies edition
It might be the next best thing to a coronavirus vaccine.
Scientists have devised a way to use the antibody-rich blood plasma of COVID-19 survivors for an upper-arm injection that they say could inoculate people against the virus for months.
Using technology that’s been proven effective in preventing other diseases such as hepatitis A, the injections would be administered to high-risk healthcare workers, nursing home patients, or even at public drive-through sites — potentially protecting millions of lives, the doctors and other experts say.
The two scientists who spearheaded the proposal — an 83-year-old shingles researcher and his counterpart, an HIV gene therapy expert — have garnered widespread support from leading blood and immunology specialists, including those at the center of the nation’s COVID-19 plasma research.
But the idea exists only on paper. Federal officials have twice rejected requests to discuss the proposal, and pharmaceutical companies — even acknowledging the likely efficacy of the plan — have declined to design or manufacture the shots, according to a Times investigation. The lack of interest in launching development of immunity shots comes amid heightened scrutiny of the federal government’s sluggish pandemic response.
Here is more from the LA Times, substantive throughout, via Anecdotal.
Bloody Well Pay Them
The United States is one of the few countries in the world where plasma donors are paid and it is responsible for 70% of the global supply of plasma. If you add in the other countries that allow donors to be paid, including Germany, Austria, Hungary, and Czechia, the paid-donor countries account for nearly 90% of the total supply.
Countries that follow the WHOs guidance to rely exclusively on voluntary, unpaid donors all have shortages of plasma (hmmm…what’s the WHOs track record like?) So what do these countries do? Import plasma from the paid-donor countries. The United Kingdom, Australia, New Zealand and some Canadian provinces, for example, prohibit paid donors and they import a majority of their plasma from paid donor countries. (See chart at right).
As Nobel prize winner Al Roth puts it, in his gentle way:
I find confusing the position of some countries that compensating domestic plasma donors is immoral, but filling the resulting shortage by purchasing plasma from the US is ok.
The UK, Australia, New Zealand and Canada can afford their moral hypocrisy but their decision to forbid paid-donors reduces the world supply of plasma driving up the price and harming people in poorer countries.
I have cribbed from an excellent new report by Peter Jaworski, Bloody Well Pay Them: The Case for Voluntary Remunerated Plasma Collections.
Previous MR posts on plasma.
The shift of prevalance toward the young
Half of new coronavirus infections in Washington [state] are now occurring in people under the age of 40, a marked shift from earlier in the epidemic when more than two-thirds of those testing positive were in older age groups.
A new analysis finds that by early May, 39% of confirmed cases statewide were among people age 20 to 39, while those 19 and younger accounted for 11%.
Here is the full article, via Anecdotal. A number of points:
1. As people adjust, and the higher-risk individuals take greater precautions, and the lower risk people relax their vigilance, this is likely to happen.
2. The case for age segregation, as a remedy and protection, becomes stronger. If your policy prescriptions never change over the course of a pandemic, you are not paying sufficient attention, or you are a dogmatist, or both.
3. Universities have to worry a bit less about their students and a bit more about their faculty, at the margin.
4. As more young people acquire immunity, the incentive for yet additional young people to invest in immunity, through stochastic deliberate exposure, rises. That in turn strengthens #2 and #3.
5. Will markets play a further role in this trend? The excellent Kevin Lewis sends me the following (WSJ):
…while surging demand has proven a boon for the traders known as blood brokers who source this commodity, diagnostic companies say high prices for the blood of recovered Covid-19 patients are posing a hurdle to developing tests. ‘We’ve had a terrible time trying to obtain positive specimens at a decent rate,’ said Stefanie Lenart-Dallezotte, manager of business operations for San Diego-based Epitope Diagnostics Inc., which sells an antibody test for Covid-19…She said one broker quoted $1,000 for a one-milliliter sample of convalescent plasma, a term for the antibody-containing part of the blood from recovered patients. Executives at other diagnostics companies say they have been quoted prices of several thousand dollars for one milliliter of plasma.
What is the market-clearing price here, and what is the elasticity of exposure with respect to that price? Evolving…
Wednesday assorted links
1. “Variation in skill can explain 44 percent of the variation in diagnostic decisions, and policies that improve skill perform better than uniform decision guidelines.” Not a Covid-19 paper, but relevant of course, link here.
2. Which states are practicing social distancing the most? (NYT)
3. Human challenge studies to accelerate a vaccine.
4. My Bloomberg column on how the macroeconomics of Covid-19 do and do not resemble WWII. Oops, correct link here.
5. The idea of “group testing” actually came from economist Robert Dorfman of Harvard (who taught me history of economic thought way back when). And more on pooled tests. And Nebraska is doing pooling.
6. “Use Surplus Federal Real Property to Expand Medical and Quarantine Capacity for COVID-19.”
7. Why scaling up testing is so hard (New Yorker).
8. We still don’t know the CFR for H1N1.
9. “Overlooked is the possibility that beauty can influence college admissions.” But not for Chinese it seems.
10. Mullainathan and Thaler with some deregulatory suggestions (NYT).
12. Benjamin Yeoh on early vaccine use.
13. James Stock: “The most important conclusion from this exercise is that policy hinges critically on a key unknown
parameter, the fraction of infected who are asymptomatic. Evidence on this parameter is scanty, however
it could readily be estimated by randomized testing.”
14. Two elite factions in tension with each other (nasty stuff, please do not read).
New York Will Try Convalescent Blood Therapy
On March 17 I wrote: “A simple and medically feasible strategy is available now for treating COVID-19 patients, transfuse blood plasma from recovered patients.” New York, with other states following closely behind, is now trying the idea.
NBC News: Hoping to stem the toll of the state’s surging coronavirus outbreak, New York health officials plan to begin collecting plasma from people who have recovered and injecting the antibody-rich fluid into patients still fighting the virus.
Gov. Andrew Cuomo announced the plans during a news briefing Monday. The treatment, known as convalescent plasma, dates back centuries and was used during the flu epidemic of 1918 — in an era before modern vaccines and antiviral drugs.
Some experts say the treatment, although somewhat primitive, might be the best hope for combating the coronavirus until more sophisticated therapies can be developed, which could take several months.
The FDA acted quickly to approve the therapy on an emergency case-by-case basis, although it’s not clear to me that legally they should be involved at all given the therapy seems more like an off-label use of blood plasma than a new drug.
Convalescent Blood Therapy
A simple and medically feasible strategy is available now for treating COVID-19 patients, transfuse blood plasma from recovered patients. The idea is that the antibodies from the recovered patients will help the infected patients. The idea is an old one and has been used before with some success. Here is Robert Kruse from Johns Hopkins (who also makes other suggestions):
A simple but potentially very effective tool that can be used in infectious outbreaks is to use the serum of patients who have recovered from the virus to treat patients who contract the virus in the future. Patients with resolved viral infection will develop a polyclonal antibody immune response to different viral antigens of 2019-nCoV. Some of these polyclonal anti-bodies will likely neutralize the virus and prevent new rounds of infection, and the patients with resolved infection should produce 2019-nCoV antibodies in high titer.Patients with resolved cases of 2019-nCoV can simply donate plasma, and then this plasma can be transfused into infected patients. Given that plasma donation is well established, and the transfusion of plasma is also routine medical care, this proposal does not need any new science or medical approvals in order to be put into place. Indeed, the same rationale was used in the treatment of several Ebola patients with convalescent serum during the outbreak in 2014–2015, including two American healthcare workers who became infected.
As the outbreak continues, more patients who survived infection will become available to serve as donors to make antisera for 2019-nCoV, and a sizeable stock of antisera could be developed to serve as a treatment for the sickest patients.
Kruse worries that the exponential growth of the pandemic will be too fast but I think he makes a mistake. The number of recovered patients will far exceed the number of hospitalized patients so the supply of plasma will rise more quickly than the demand.
Convalescent blood therapy was used to treat people during the 1918 flu pandemic and appeared to be useful (see here for references to papers from that time.) A recent meta-analysis of patients treated with blood therapy during the 1918 flu found good results (noting, of course, that data from a hundred years ago wasn’t ideal) :
Patients with Spanish influenza pneumonia who received influenza-convalescent human blood products may have experienced a clinically important reduction in the risk for death. Convalescent human H5N1 plasma could be an effective, timely, and widely available treatment that should be studied in clinical trials.
Blood therapy has also been used periodically since that time to treat Ebola patients, MERS patients, Junin patients and others but under non-ideal conditions where lots of things were being tried at the same time and controls were not ideal. Results have been mostly positive or non-negative, e.g. this study on 84 Ebola patients found few benefits but also small costs. Blood therapy has also been used for animals.
To implement we need a database of recovered patients. The recovered patients then needed to be tested to find those with the most antibodies. It is probably best to use recovered patients from the same location to maximize overlap although the Chinese brought plasma from China to Italy. Most of the dangers from blood transfusion such as passing on another disease are well understood and should be manageable with testing and knowledge of donors. In rare cases such as Dengue it can bad to stimulate the immune system (see discussion here).
Plasma therapy is not difficult and there are firms with expertise in the field including Takeda and Regenernon the latter of whom developed a blood based treatment for Ebola. Thus, CBP seems worthy of consideration.
Hat tip: Monique van Hoek.
From the comments, Vitalik Buterin
Analyst
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I’ll answer this one here in detail because it’s probably too technical for it to be valuable to put a good answer into a Conversation with Tyler.
> 1. In retrospect, was it a good decision to have ethereum bytecodes executed on every single mining node? And if not, would he have selected sharding and plasma or a different solution?
Ultimately the answer is, yes given the knowledge we had at the time, no given what we know today. If I was doing Ethereum back then with the knowledge that I have today, I would obviously shoot straight for exactly the design that the research team is shooting for today (Casper PoS, sharding), and I would have actively encouraged developers to work on state channels and Plasma from day 1. Layer 1 scaling (sharding) and layer 2 scaling (state channels and Plasma) are complementary; gains from the two are multiplicative with each other, so it’s not a matter of A vs B, it’s A and B.
Ultimately, for a distributed validation system to work, you need to satisfy two properties:
1. There are enough (randomly sampled) nodes on average validating any given piece of data that invalid data will under no circumstances get through.
2. There are mechanisms that can ensure that if bad data *does* get through (eg. because of a 51% attack), then clients can detect this. In a sharded system, there is obviously too much data for clients to verify directly, but there are indirect approaches that can be used that can give equivalent assurances with some additional security assumptions (STARKs, fraud proofs, data availability proofs…)> 2. How confident is he that transitioning to proof-of-stake will be successful? What are the risks of proof-of-stake?
Close to 100% confident that proof of stake is possible in principle; many chains are using (crappy versions of) it already. There’s obviously the question of how strong properties we can achieve with PoS though, and there are some edges of that that are still being worked out. The main risks that I see are (i) weird game-theoretic attacks on the specific design that we end up going with, and (ii) pool centralization.
IMO Satoshi’s PoW is really nice in part because of its sheer simplicity; the simplicity helps with decentralization because pretty much anyone can understand how it works, whereas traditional non-PoW consensus algos like PBFT are far more complex. Casper FFG was designed in part to replicate something close to PoW-style simplicity while still having the safety and liveness properties of traditional BFT consensus algos; and I’m obviously interested in minimizing complexity of the sharding design as well.
Here is the link, he offers several other “highly technical” answers in the comments.
Money for Blood is Good for All
The Economist: For years [Barzin Bahardoust] has been trying to pay Canadians for their blood plasma—the viscous straw-coloured liquid in blood that has remarkable therapeutic powers. When his firm, Canadian Plasma Resources (CPR), tried to open clinics in Ontario in 2014, a campaign by local activists led to a ban by the provincial government on paid plasma collection. Undeterred, he tried another province, Alberta—which also banned the practice last year. Then, on April 26th, when CPR announced a planned centre in British Columbia, its government said it too was considering similar legislation. CPR has managed to open two centres, in far-flung Saskatchewan and New Brunswick. Even these have faced opposition.
The global demand for plasma is growing, and cannot be met through altruistic donations alone. Global plasma exports were worth $126bn in 2016—more than exports of aeroplanes.
…Only countries that pay for plasma are self-sufficient in it. (Italy, where donors are given time off work, is close to self-sufficiency.) Half of America’s plasma is shipped to Europe—20m contributions-worth. Canada imports 80% of its plasma products from America. Australia imports 40% of its plasma products, too.
It’s a very odd “ethical policy” that leads Canadian provinces to ban paying Canadians for plasma but then import paid plasma from the United States. I am one of the signatories (along with Al Roth, Vernon Smith and Gerald Dworkin among others) of a letter that argues for the efficiency and ethics of allowing compensation for blood plasma donation. The Economist riffs of this letter in a very good op-ed:
The aversion to paid plasma rests on three reasonable-sounding but largely groundless propositions. The first is that it is unsafe. Payment might encourage donors to conceal dangerous behaviour—such as intravenous drug use. In the 1980s and 1990s, tainted blood products infected half the world’s haemophiliacs with HIV, along with tens of thousands of plasma donors in China. But modern plasma products do not carry such risks. They are heat-treated and bathed in chemicals to sanitise them (an impossibility for blood for transfusion). Since the adoption of these techniques there has not been a single case of transmission of HIV or hepatitis via plasma products. Doctors agree that plasma products from paid donors are just as safe as those from unpaid ones.
A second argument is that, if people are paid for their plasma, fewer will volunteer to donate whole blood for transfusions. (Paying for whole blood would be unwise, since it cannot be sterilised as plasma can.) But there is no evidence that paying for plasma diminishes the supply of donated blood. That is why, in Canada, more than 30 economists and philosophers wrote an open letter arguing against bans on paid plasma. Americans voluntarily donate as much blood per person as do Canadians.
A third argument is that paying for plasma preys on the poor. It is possible that those selling plasma need the money and therefore might give too often. In America plasma donors can give twice a week; those in Europe can give just once a week. There is no evidence of harm to their health in either case, but more long-term study would be prudent.
Those against allowing payment suggest using voluntary donors instead. Yet every country that does not pay ends up importing plasma. And the fact that America is by far the dominant supplier carries risks of its own. The dependence on a single source leaves the rest of the world vulnerable to an interruption of supply. To protect their people, therefore, other governments need to diversify their supplies of plasma. Paying for it would make a big difference.
Canada Imports Precious Bodily Fluids
In 2004 Canada prohibited paying Canadian sperm donors, leading to a tremendous shortage as I had predicted in 2003 (see also my post, The Great Canadian Sperm Shortage). Canadian Peter Jaworski has an update (oddly enough published in USA Today):
Canada used to have a sufficient supply of domestic sperm donors. But in 2004, we passed the Assisted Human Reproduction Act, which made it illegal to compensate donors for their sperm. Shortly thereafter, the number of willing donors plummeted, and sperm donor clinics were shuttered. Now, there is basically just one sperm donor clinic in Canada, and 30-70 Canadian men who donate sperm. Since demand far outstrips supply, we turn to you. We import sperm from for-profit companies in the U.S., where compensating sperm donors is both legal and normal.
Note, by the way, that contrary to what you might expect from Titmuss et al. US sperm is considered to be of high quality because it comes with information about the donor.
And sperm isn’t the only precious bodily fluid that Canada imports.
Canada has never had enough domestic blood plasma for plasma-protein products, such as immune globulin. Our demand for those products, however, is increasing. Last year, we collected only enough blood plasma from unremunerated donors to manufacture 17% of the immune globulin demanded. The rest we imported from you, in exchange for $623 million, or $512 million U.S.
Reliance on your blood plasma looked like it might change a little bit when, in 2012, a company called Canadian Plasma Resources announced plans to open clinics in Ontario dedicated to collecting blood plasma. The trouble is that its business model included compensating donors. Almost immediately, groups such as the Canadian Union of Public Employees and the Canadian Health Coalition began to lobby the Ontario government to pass a law to stop CPR from opening clinics. Ontario obliged in 2014, passing the Safeguarding Health Care Integrity Act, which among other things made compensation illegal.
…As for safety, the fact that we import products made with remunerated donors should tell you that it is emphatically not an issue. Health Canada has said that there is no health concern. The CEO of Canadian Blood Services, Graham Sher, took to YouTube to explain that “it is categorically untrue to say, in 2015 or 2016, that plasma-protein products from paid donors are less safe or unsafe. They are not. They are as safe as the products that are manufactured from our non-remunerated or unpaid donors.”
As Jaworski writes:
What Canada should do is legalize compensation for renewable bodily fluids in our own country. It would be the morally right thing to do. It would help make and save more lives, without harming anybody.
From the comments, on a fusion reactor
So for once I can intelligently comment on a Marginal Revolution article. (I have a Ph.D. in applied plasma physics and fusion energy; I worked on the “conventional” fusion reactor design, the tokamak). Lockheed hasn’t released many details of their concept (at least, not enough details that it can actually be evaluated in technical detail), but it looks like it’s a combination of a magnetic mirror and a levitated dipole. The magnetic mirror was studied in detail in the 1960s and 1970s and didn’t work out (due to [detailed plasma physics reasons]) and the levitated dipole has a fundamental flaw as a power-producing reactor in that the superconducting magnets are inside the neutron shielding – neutrons destroy the magnets.
It’s tough as a scientist to be able to comment on things like this, because it’s “science by press release”, i.e. there’s a big media hype but the actual researchers don’t release enough technical details to actually evaluate it. One wants to remain cautiously optimistic, but with fusion in particular, we’ve been down this road many, many times. Thus I predict that the most likely outcome is that as they scale their device up, they’ll find that the confinement (a measure of how well the device holds a fusion plasma) unexpectedly drops off due to some different types of turbulence turning on at higher temperatures / higher pressures… and it will quietly go away.
I hope that I am proven wrong.
There are other interesting comments at the link and Kottke offers more.
1. In retrospect, was it a good decision to have ethereum bytecodes executed on every single mining node? And if not, would he have selected sharding and plasma or a different solution?
2. How confident is he that transitioning to proof-of-stake will be successful? What are the risks of proof-of-stake?