Blood Money: Paying for Convalescent Plasma to Treat COVID-19
Convalescent plasma – first used to treat diphtheria in 1890 – has been dusted off the shelf to treat COVID-19. Does it work? Should we rely strictly on the altruism of donors or should people be paid for it?
The biologic theory is that a person who has recovered from a disease has chemicals in their blood, most likely antibodies, that contributed to their recovery, and transferring those to a person who is sick might aid their recovery. Whole blood won't work because there are too few antibodies in a single unit of blood and the body can hold only so much of it.
Plasma comprises about 55 percent of whole blood and is what's left once you take out the red blood cells that carry oxygen and the white blood cells of the immune system. Most of it is water but the rest is a complex mix of fats, salts, signaling molecules and proteins produced by the immune system, including antibodies.
A process called apheresis circulates the donors' blood through a machine that separates out the desired parts of blood and returns the rest to the donor. It takes several times the length of a regular whole blood donation to cycle through enough blood for the process. The end product is a yellowish concentration called convalescent plasma.
Recent History
It was used extensively during the great influenza epidemic off 1918 but fell out of favor with the development of antibiotics. Still, whenever a new disease emerges – SARS, MERS, Ebola, even antibiotic-resistant bacteria – doctors turn to convalescent plasma, often as a stopgap until more effective antibiotic and antiviral drugs are developed. The process is certainly safe when standard procedures for handling blood products are followed, and historically it does seem to be beneficial in at least some patients if administered early enough in the disease.
With few good treatment options for COVID-19, doctors have given convalescent plasma to more than a hundred thousand Americans and tens of thousand of people elsewhere, to mixed results. Placebo-controlled trials could give a clearer picture of plasma's value but it is difficult to enroll patients facing possible death when the flip of a coin will determine who will receive a saline solution or plasma.
And the plasma itself isn't some uniform pill stamped out in a factory, it's a natural product that is shaped by the immune history of the donor's body and its encounter not just with SARS-CoV-2 but a lifetime of exposure to different pathogens.
Researchers believe antibodies in plasma are a key factor in directly fighting the virus. But the variety and quantity of antibodies vary from donor to donor, and even over time from the same donor because once the immune system has cleared the virus from the body, it stops putting out antibodies to fight the virus. Often the quality and quantity of antibodies being given to a patient are not measured, making it somewhat hit or miss, which is why several companies have recently developed monoclonal antibodies, a single type of antibody found in blood that is effective against SARS-CoV-2 and that is multiplied in the lab for use as therapy.
Plasma may also contain other unknown factors that contribute to fighting disease, say perhaps signaling molecules that affect gene expression, which might affect the movement of immune cells, their production of antiviral molecules, or the regulation of inflammation. The complexity and lack of standardization makes it difficult to evaluate what might be working or not with a convalescent plasma treatment. Thus researchers are left with few clues about how to make it more effective.
Industrializing Plasma
Many Americans living along the border with Mexico regularly head south to purchase prescription drugs at a significant discount. Less known is the medical traffic the other way, Mexicans who regularly head north to be paid for plasma donations, which are prohibited in their country; the U.S. allows payment for plasma donations but not whole blood. A typical payment is about $35 for a donation but the sudden demand for convalescent plasma from people who have recovered from COVID-19 commands a premium price, sometimes as high as $200. These donors are part of a fast-growing plasma industry that surpassed $25 billion in 2018. The U.S. supplies about three-quarters of the world's needs for plasma.
Payment for whole blood donation in the U.S. is prohibited, and while payment for plasma is allowed, there is a stigma attached to payment and much plasma is donated for free.
The pharmaceutical industry has shied away from natural products they cannot patent but they have identified simpler components from plasma, such as clotting factors and immunoglobulins, that have been turned into useful drugs from this raw material of plasma. While some companies have retooled to provide convalescent plasma to treat COVID-19, often paying those donors who have recovered a premium of several times the normal rate, most convalescent plasma has come as donations through traditional blood centers.
In April the Mayo Clinic, in cooperation with the FDA, created an expanded access program for convalescent plasma to treat COVID-19. It was meant to reduce the paperwork associated with gaining access to a treatment not yet approved by the FDA for that disease. Initially it was supposed to be for 5000 units but it quickly grew to more than twenty times that size. Michael Joyner, the head of the program, discussed that experience in an extended interview in September.
The Centers for Medicare and Medicaid Services (CMS) also created associated reimbursement codes, which became permanent in August.
Mayo published an analysis of the first 35,000 patients as a preprint in August. It concluded, "The relationships between mortality and both time to plasma transfusion, and antibody levels provide a signature that is consistent with efficacy for the use of convalescent plasma in the treatment of hospitalized COVID-19 patients."
It seemed to work best when given early in infection and in larger doses; a similar pattern has been seen in studies of monoclonal antibodies. A revised version will soon be published in a major medical journal. Some criticized the findings as not being from a randomized clinical trial.
Convalescent plasma is not the only intervention that seems to work better when used earlier in the course of disease. Recently the pharmaceutical company Eli Lilly stopped a clinical trial of a monoclonal antibody in hospitalized COVID-19 patients when it became apparent it wasn't helping. It is continuing trials for patients who are less sick and begin treatment earlier, as well as in persons who have been exposed to the virus but not yet diagnosed as infected, to see if it might prevent infection. In November the FDA eased access to this drug outside of clinical trials, though it is not yet approved for sale.
Show Me the Money
The antibodies that seem to give plasma its curative powers are fragile proteins that the body produces to fight the virus. Production shuts down once the virus is cleared and the remaining antibodies survive only for a few weeks before the levels fade. [Vaccines are used to train immune cells to produce antibodies and other defenses to respond to exposure to future pathogens.] So they can be usefully harvested from a recovered patient for only a few short weeks or months before they decline precipitously. The question becomes, how does one mobilize this resource in that short window of opportunity?
The program run by the Mayo Clinic explains the process and criteria for donating convalescent plasma for COVID-19, as well as links to local blood centers equipped to handle those free donations. Commercial plasma centers also are advertising and paying for donations.
A majority of countries prohibit paying donors for blood or blood products, including India. But an investigation by India Today touted a black market of people willing to donate convalescent plasma for the equivalent of several hundred dollars. Officials vowed to prosecute, saying donations should be selfless.
But that enforcement threat seemed to be undercut when the health minister of the state of Assam declared "plasma donors will get preference in several government schemes including the government job interview." It appeared to be a form of compensation that far surpassed simple cash.
The small city of Rexburg, Idaho, with a population a bit over 50,000, overwhelmingly Mormon and home to a campus of Brigham Young University, at one point had one of the highest per capita rates of COVID-19 in the current wave of infection. Rumors circulated that some students were intentionally trying to become infected so they could later sell their plasma for top dollar, potentially as much as $200 a visit.
Troubled university officials investigated the allegations but could come up with nothing definitive; how does one prove intentionality with such an omnipresent yet elusive virus? They chalked it up to idle chatter, perhaps an urban legend, which might be associated with alcohol use on some other campus.
Doctors, hospitals, and drug companies are all rightly praised for their altruism in the fight against COVID-19, but they also get paid. Payment for whole blood donation in the U.S. is prohibited, and while payment for plasma is allowed, there is a stigma attached to payment and much plasma is donated for free. "Why do we expect the donors [of convalescent plasma] to be the only uncompensated people in the process? It really makes no sense," argues Mark Yarborough, an ethicist at the UC Davis School of Medicine in Sacramento.
"When I was in grad school, two of my closest friends, at least once a week they went and gave plasma. That was their weekend spending money," Yarborough recalls. He says upper and middle-income people may have the luxury of donating blood products but prohibiting people from selling their plasma is a bit paternalistic and doesn't do anything to improve the economic status of poor people.
"Asking people to dedicate two hours a week for an entire year in exchange for cookies and milk is demonstrably asking too much," says Peter Jaworski, an ethicist who teaches at Georgetown University.
He notes that companies that pay plasma donors have much lower total costs than do operations that rely solely on uncompensated donations. The companies have to spend less to recruit and retain donors because they increase payments to encourage regular repeat donations. They are able to more rationally schedule visits to maximize use of expensive apheresis equipment and medical personnel used for the collection.
It seems that COVID-19 has been with us forever, but in reality it is less than a year. We have learned much over that short time, can now better manage the disease, and have lower mortality rates to prove it. Just how much convalescent plasma may have contributed to that remains an open question. Access to vaccines is months away for many people, and even then some people will continue to get sick. Given the lack of proven treatments, it makes sense to keep plasma as part of the mix, and not close the door to any legitimate means to obtain it.
Stronger psychedelics that rewire the brain, with Doug Drysdale
A promising development in science in recent years has been the use technology to optimize something natural. One-upping nature's wisdom isn't easy. In many cases, we haven't - and maybe we can't - figure it out. But today's episode features a fascinating example: using tech to optimize psychedelic mushrooms.
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These mushrooms have been used for religious, spiritual and medicinal purposes for thousands of years, but only in the past several decades have scientists brought psychedelics into the lab to enhance them and maximize their therapeutic value.
Today’s podcast guest, Doug Drysdale, is doing important work to lead this effort. Drysdale is the CEO of a company called Cybin that has figured out how to make psilocybin more potent, so it can be administered in smaller doses without side effects.
The natural form of psilocybin has been studied increasingly in the realm of mental health. Taking doses of these mushrooms appears to help people with anxiety and depression by spurring the development of connections in the brain, an example of neuroplasticity. The process basically shifts the adult brain from being fairly rigid like dried clay into a malleable substance like warm wax - the state of change that's constantly underway in the developing brains of children.
Neuroplasticity in adults seems to unlock some of our default ways of of thinking, the habitual thought patterns that’ve been associated with various mental health problems. Some promising research suggests that psilocybin causes a reset of sorts. It makes way for new, healthier thought patterns.
So what is Drysdale’s secret weapon to bring even more therapeutic value to psilocybin? It’s a process called deuteration. It focuses on the hydrogen atoms in psilocybin. These atoms are very light and don’t stick very well to carbon, which is another atom in psilocybin. As a result, our bodies can easily breaks down the bonds between the hydrogen and carbon atoms. For many people, that means psilocybin gets cleared from the body too quickly, before it can have a therapeutic benefit.
In deuteration, scientists do something simple but ingenious: they replace the hydrogen atoms with a molecule called deuterium. It’s twice as heavy as hydrogen and forms tighter bonds with the carbon. Because these pairs are so rock-steady, they slow down the rate at which psilocybin is metabolized, so it has more sustained effects on our brains.
Cybin isn’t Drysdale’s first go around at this - far from it. He has over 30 years of experience in the healthcare sector. During this time he’s raised around $4 billion of both public and private capital, and has been named Ernst and Young Entrepreneur of the Year. Before Cybin, he was the founding CEO of a pharmaceutical company called Alvogen, leading it from inception to around $500 million in revenues, across 35 countries. Drysdale has also been the head of mergers and acquisitions at Actavis Group, leading 15 corporate acquisitions across three continents.
In this episode, Drysdale walks us through the promising research of his current company, Cybin, and the different therapies he’s developing for anxiety and depression based not just on psilocybin but another psychedelic compound found in plants called DMT. He explains how they seem to have such powerful effects on the brain, as well as the potential for psychedelics to eventually support other use cases, including helping us strive toward higher levels of well-being. He goes on to discuss his views on mindfulness and lifestyle factors - such as optimal nutrition - that could help bring out hte best in psychedelics.
Show links:
Doug Drysdale full bio
Doug Drysdale twitter
Cybin website
Cybin development pipeline
Cybin's promising phase 2 research on depression
Johns Hopkins psychedelics research and psilocybin research
Mets owner Steve Cohen invests in psychedelic therapies
Doug Drysdale, CEO of Cybin
How the body's immune resilience affects our health and lifespan
Story by Big Think
It is a mystery why humans manifest vast differences in lifespan, health, and susceptibility to infectious diseases. However, a team of international scientists has revealed that the capacity to resist or recover from infections and inflammation (a trait they call “immune resilience”) is one of the major contributors to these differences.
Immune resilience involves controlling inflammation and preserving or rapidly restoring immune activity at any age, explained Weijing He, a study co-author. He and his colleagues discovered that people with the highest level of immune resilience were more likely to live longer, resist infection and recurrence of skin cancer, and survive COVID and sepsis.
Measuring immune resilience
The researchers measured immune resilience in two ways. The first is based on the relative quantities of two types of immune cells, CD4+ T cells and CD8+ T cells. CD4+ T cells coordinate the immune system’s response to pathogens and are often used to measure immune health (with higher levels typically suggesting a stronger immune system). However, in 2021, the researchers found that a low level of CD8+ T cells (which are responsible for killing damaged or infected cells) is also an important indicator of immune health. In fact, patients with high levels of CD4+ T cells and low levels of CD8+ T cells during SARS-CoV-2 and HIV infection were the least likely to develop severe COVID and AIDS.
Individuals with optimal levels of immune resilience were more likely to live longer.
In the same 2021 study, the researchers identified a second measure of immune resilience that involves two gene expression signatures correlated with an infected person’s risk of death. One of the signatures was linked to a higher risk of death; it includes genes related to inflammation — an essential process for jumpstarting the immune system but one that can cause considerable damage if left unbridled. The other signature was linked to a greater chance of survival; it includes genes related to keeping inflammation in check. These genes help the immune system mount a balanced immune response during infection and taper down the response after the threat is gone. The researchers found that participants who expressed the optimal combination of genes lived longer.
Immune resilience and longevity
The researchers assessed levels of immune resilience in nearly 50,000 participants of different ages and with various types of challenges to their immune systems, including acute infections, chronic diseases, and cancers. Their evaluation demonstrated that individuals with optimal levels of immune resilience were more likely to live longer, resist HIV and influenza infections, resist recurrence of skin cancer after kidney transplant, survive COVID infection, and survive sepsis.
However, a person’s immune resilience fluctuates all the time. Study participants who had optimal immune resilience before common symptomatic viral infections like a cold or the flu experienced a shift in their gene expression to poor immune resilience within 48 hours of symptom onset. As these people recovered from their infection, many gradually returned to the more favorable gene expression levels they had before. However, nearly 30% who once had optimal immune resilience did not fully regain that survival-associated profile by the end of the cold and flu season, even though they had recovered from their illness.
Intriguingly, some people who are 90+ years old still have optimal immune resilience, suggesting that these individuals’ immune systems have an exceptional capacity to control inflammation and rapidly restore proper immune balance.
This could suggest that the recovery phase varies among people and diseases. For example, young female sex workers who had many clients and did not use condoms — and thus were repeatedly exposed to sexually transmitted pathogens — had very low immune resilience. However, most of the sex workers who began reducing their exposure to sexually transmitted pathogens by using condoms and decreasing their number of sex partners experienced an improvement in immune resilience over the next 10 years.
Immune resilience and aging
The researchers found that the proportion of people with optimal immune resilience tended to be highest among the young and lowest among the elderly. The researchers suggest that, as people age, they are exposed to increasingly more health conditions (acute infections, chronic diseases, cancers, etc.) which challenge their immune systems to undergo a “respond-and-recover” cycle. During the response phase, CD8+ T cells and inflammatory gene expression increase, and during the recovery phase, they go back down.
However, over a lifetime of repeated challenges, the immune system is slower to recover, altering a person’s immune resilience. Intriguingly, some people who are 90+ years old still have optimal immune resilience, suggesting that these individuals’ immune systems have an exceptional capacity to control inflammation and rapidly restore proper immune balance despite the many respond-and-recover cycles that their immune systems have faced.
Public health ramifications could be significant. Immune cell and gene expression profile assessments are relatively simple to conduct, and being able to determine a person’s immune resilience can help identify whether someone is at greater risk for developing diseases, how they will respond to treatment, and whether, as well as to what extent, they will recover.