Coronavirus treatment options and the impact on public policy

A 5 day course of treatment was found to be more effective than a 10 day course (preliminary data), so these numbers can probably be doubled.
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Working to Supply Remdesivir for COVID-19
Current and Projected Supply
As of January 2020, we were not actively manufacturing remdesivir. The manufacturing supply chain was scaled to periodically make small amounts of product for a compound in early development. We had inventory of finished product to treat just 5,000 patients.

Since then, we have proactively and rapidly scaled our supply chain. As of late March, using the active ingredient we already had in our inventory, we have increased our supply to more than 30,000 patient courses of remdesivir on hand, assuming a 10-day course of treatment for patients. As new raw materials arrive over the next few weeks from manufacturing partners around the world, our available supply will begin to rapidly increase.

Every day we are improving processes, shortening timelines and increasing volumes as we work to bring remdesivir to patients as soon as possible. Our goal is to produce a total of:

• More than 140,000 treatment courses by the end of May 2020
• More than 500,000 treatment courses by October 2020
• More than 1 million treatment courses by December 2020
• Several million treatment courses in 2021, if required

A great time for Donald to fuck with China! Good luck with Trump hoarding it either, it would be wise to have the whole supply chain in America though.

"Gilead is also trying to ramp up manufacturing at a time when supply chains for raw materials have been threatened by the very pandemic the drug is trying to combat.

“Most raw materials and most active pharmaceutical ingredients are made in Asia, either in China or India,” said Greg Dombal, the president of the life-sciences-focused Halloran Consulting Group. “That supply chain spiders all the way across the world.”"


Gilead’s remdesivir has seen success against the coronavirus. Now the company has to make enough to supply the world

In January, Gilead Sciences wasn’t manufacturing more than a few doses of its experimental antiviral remdesivir. The drug wasn’t being studied in any major clinical trials. The company had enough on hand to treat 5,000 people.

A few months and the onset of one coronavirus pandemic later, demand for remdesivir is booming. A study run by the National Institute of Allergy and Infectious Diseases showed that patients with Covid-19 who were given the drug recovered faster than those who were given a placebo, the agency said this week. Regulators have not yet approved the drug — though an emergency authorization is reportedly imminent — but the company now stands in the position of having to scale up production of a drug that the whole world may want.

Gilead is working to meet the need. Already, it is up to 50,000 treatment courses, with a goal of having “multiple millions of treatment courses” by the end of the year, CEO Daniel O’Day told STAT Wednesday. Still, the realities of manufacturing pharmaceuticals limit how much a company can churn out and how fast that can be increased, experts say.

“We’re going to make sure that access is not an issue with this medicine,” O’Day told STAT. “This is a global pandemic. There should be no question about our ability to get medicine in the hands of patients.”

Related:
Gilead CEO: We’re going to make sure that access is not an issue with remdesivir
Making an intravenous drug like remdesivir is not a simple process. Filling a vial requires a whole lot of different pieces — many of which are made by other companies — coming together in a final product that has to be pure, sterile, and the same each time. It involves a series of chemical steps that are completed in a particular sequence and ends with a manual inspection of each vial, a process that is “both resource- and time-intensive, with some individual manufacturing steps taking weeks to complete,” Gilead wrote in a description of its efforts. Every aspect has to be performed under strict regulatory and safety rules to ensure the drug’s standards.

“You don’t just turn a dial and say, ‘Hey, we’re going to start making this,’” said Bernhardt Trout, a professor of chemical engineering at the Massachusetts Institute of Technology, who studies manufacturing technologies.

“It’s not just the active ingredient — there are additives,” Trout said. “Those have to be pharmaceutical grade and safe and tested. Every time you get an ingredient, you have to test that and make sure it falls within specifications. You have to analyze impurities. You have to have a quality control system. You have to then scale up your process to make millions of doses or whatever it is, and show that your process is robust because there are always variations.”

Gilead is also trying to ramp up manufacturing at a time when supply chains for raw materials have been threatened by the very pandemic the drug is trying to combat.

“Most raw materials and most active pharmaceutical ingredients are made in Asia, either in China or India,” said Greg Dombal, the president of the life-sciences-focused Halloran Consulting Group. “That supply chain spiders all the way across the world.”

Gilead has been preparing. It started building up production when it became clear in the early days of the pandemic that remdesivir might be effective against Covid-19. The company has tapped partners to make the drug as well. It’s been procuring raw materials and accelerated the manufacturing process from one that took nine to 12 months to complete to one that takes six to eight months.

“Immediately in January, when we knew there was even a possibility this medicine could be effective … we made the commitment as a company to say, this is too important,” O’Day said. “We have to make every investment that we can in the event that this works given the human need and the societal need here.”
more...

Prognosis
Scientists Create Antibody That Defeats Coronavirus in Lab

• Antibody known as 47D11 prevented Covid-19 and SARS in study
• Early findings made in the lab may not be confirmed in humans

Scientists created a monoclonal antibody that can defeat the new coronavirus in the lab, an early but promising step in efforts to find treatments and curb the pandemic’s spread.

The experimental antibody has neutralized the virus in cell cultures. While that’s early in the drug development process -- before animal research and human trials -- the antibody may help prevent or treat Covid-19 and related diseases in the future, either alone or in a drug combination, according to a study published Monday in the journal Nature Communications.

More research is needed to see whether the findings are confirmed in a clinical setting and how precisely the antibody defeats the virus, Berend-Jan Bosch of Utrecht University in the Netherlands and colleagues wrote in the paper.

The antibody known as 47D11 targets the spike protein that gives the new coronavirus a crown-like shape and lets it enter human cells. In the Utrecht experiments, it didn’t just defeat the virus responsible for Covid-19 but also a cousin equipped with similar spike proteins, which causes Severe Acute Respiratory Syndrome, or SARS.

Monoclonal antibodies are lab-created proteins that resemble naturally occurring versions the body raises to fight off bacteria and viruses. Highly potent, they target exactly one site on a virus. In this case, the scientists used genetically modified mice to produce different antibodies to the spike proteins of coronaviruses. After a subsequent screening process, 47D11 emerged as showing neutralizing activity. Researchers then reformatted that antibody to create a fully human version, according to the paper.

“Monoclonal antibodies targeting vulnerable sites on viral surface proteins are increasingly recognized as a promising class of drugs against infectious diseases and have shown therapeutic efficacy for a number of viruses,” Bosch and colleagues wrote.

Monoclonal antibodies already sparked a treatment revolution in cancer, with medicines such as Merck & Co.’s Keytruda and Roche Holding AG’s Herceptin becoming some of the world’s bestsellers. AbbVie Inc.’s blockbuster inflammation treatment Humira is also part of the monoclonal antibody family.

Two such antibody therapies show promise against Ebola. Companies such as Regeneron Pharmaceuticals Inc. are also working on possible antibody treatments for the coronavirus.

Antibody blocks infection by the SARS-CoV-2 in cells, scientists discover
Date:May 4, 2020Source:Utrecht UniversitySummary:Researchers report that they have identified a fully human monoclonal antibody that prevents the SARS-CoV-2 (COVID-19) virus from infecting cultured cells. The discovery is an initial step towards developing a fully human antibody to treat or prevent the respiratory disease COVID-19 caused by the novel coronavirus SARS-CoV-2.

Researchers at Utrecht University, Erasmus Medical Center and Harbour BioMed (HBM) today reported that they have identified a fully human monoclonal antibody that prevents the SARS-CoV-2 (COVID-19) virus from infecting cultured cells. The discovery, published online today in Nature Communications, is an initial step towards developing a fully human antibody to treat or prevent the respiratory disease COVID-19 caused by the novel coronavirus SARS-CoV-2.

The COVID-19 pandemic has spread rapidly across the globe infecting more than 3.3M people worldwide and killing more than 235,000 people so far.

"This research builds on the work our groups have done in the past on antibodies targeting the SARS-CoV that emerged in 2002/2003," said Berend-Jan Bosch, Associate Professor, Research leader at Utrecht University, and co-lead author of the Nature Communications study. "Using this collection of SARS-CoV antibodies, we identified an antibody that also neutralizes infection of SARS-CoV-2 in cultured cells. Such a neutralizing antibody has potential to alter the course of infection in the infected host, support virus clearance or protect an uninfected individual that is exposed to the virus."

Dr. Bosch noted that the antibody binds to a domain that is conserved in both SARS-CoV and SARS-CoV-2, explaining its ability to neutralize both viruses. "This cross-neutralizing feature of the antibody is very interesting and suggests it may have potential in mitigation of diseases caused by future-emerging related coronaviruses."

"This discovery provides a strong foundation for additional research to characterize this antibody and begin development as a potential COVID-19 treatment," said Frank Grosveld, PhD. co-lead author on the study, Academy Professor of Cell Biology, Erasmus Medical Center, Rotterdam and Founding Chief Scientific Officer at Harbour BioMed. "The antibody used in this work is 'fully human,' allowing development to proceed more rapidly and reducing the potential for immune-related side effects." Conventional therapeutic antibodies are first developed in other species and then must undergo additional work to 'humanize' them. The antibody was generated using Harbour BioMed's H2L2 transgenic mouse technology.

"This is groundbreaking research," said Dr. Jingsong Wang, Founder, Chairman & Chief Executive Officer of HBM. "Much more work is needed to assess whether this antibody can protect or reduce the severity of disease in humans. We expect to advance development of the antibody with partners. We believe our technology can contribute to addressing this most urgent public health need and we are pursuing several other research avenues."

The paper is titled, "A human monoclonal antibody blocking SARS-VoV-2 Infection. In addition to Drs. Bosch and Grosveld, authors on the paper included: Chunyan Wang, Wentao Li and Frank van Kuppeveld of Utrecht University; Nisreen Okba and Bart Haagmans of Erasmus Medical Center (Rotterdam); Dubravka Drabek and Rien van Haperen of Erasmus Medical Center and Harbour Antibodies; and Albert Osterhaus of the University of Veterinary Medicine (Hannover, Germany).

New CRISPR-based test for Covid-19 could be a simple, cheap at-home diagnostic, scientists say

The revolutionary genetic technique better known for its potential to cure thousands of inherited diseases could also solve the challenge of Covid-19 diagnostic testing, scientists announced on Tuesday. A team headed by biologist Feng Zhang of the McGovern Institute at MIT and the Broad Institute has repurposed the genome-editing tool CRISPR into a test able to quickly detect as few as 100 coronavirus particles in a swab or saliva sample.

Crucially, the technique, dubbed a “one pot” protocol, works in a single test tube and does not require the many specialty chemicals, or reagents, whose shortage has hampered the rollout of widespread Covid-19 testing in the U.S. It takes about an hour to get results, requires minimal handling, and in preliminary studies has been highly accurate, Zhang told STAT. He and his colleagues, led by the McGovern’s Jonathan Gootenberg and Omar Abudayyeh, released the protocol on their STOPCovid.science website.

Because the test has not been approved by the Food and Drug Administration, it is only for research purposes for now. But minutes before speaking to STAT on Monday, Zhang and his colleagues were on a conference call with FDA officials about what they needed to do to receive an “emergency use authorization” that would allow clinical use of the test. The FDA has used EUAs to fast-track Covid-19 diagnostics as well as experimental therapies, including remdesivir, after less extensive testing than usually required.

For an EUA, Zhang said, the agency will require his lab to validate the test, which they call STOPCovid, on several samples. Although “it is still early in the process,” Zhang said, he and his colleagues are confident enough in its accuracy that they are conferring with potential commercial partners who could turn the test into a cartridge-like device, similar to a pregnancy test, enabling Covid-19 testing at doctor offices and other point-of-care sites.

Related:
Scientists tap CRISPR’s search-and-detect skills to create a rapid Covid-19 test

“It could potentially even be used at home or at workplaces,” Zhang said. “It’s inexpensive, does not require a lab, and can return results within an hour using a paper strip, not unlike a pregnancy test. This helps address the urgent need for widespread, accurate, inexpensive, and accessible Covid-19 testing.” Public health experts say the availability of such a test is one of the keys to safely reopening society, which will require widespread testing, and then tracing and possibly isolating the contacts of those who test positive.

The scientists are also in discussions with the Gates Foundation about distributing the testing kits. “It could be especially valuable in places where there is not the capacity for centralized testing,” Gootenberg said.

Other labs are also developing CRISPR-based Covid-19 tests. Last month scientists at the University of California, San Francisco, and Mammoth Biosciences reported that theirs takes roughly 40 minutes, compared with four to six hours for the traditional swab tests (which use a biochemical reaction called PCR and require numerous reagents). But that test appears to produce false negatives slightly more often than the PCR test. It also requires two steps, similar to one that Zhang developed in February; that adds complexity and increases the chances that samples will cross-contaminate.

Zhang’s February test is being used by hospitals in Thailand. But with his colleagues, he has spent the last two months creating the one-step version.

“The key advance for STOP is the simplification into a single-step reaction, which prevents cross contamination during step-to-step liquid transfers,” he said. “That makes it suitable for point-of-care use.”

Existing “home” Covid-19 diagnostic tests such as that from LabCorp allow people to collect the sample — that is, swab themselves — at home. The actual test must be done at a lab. Currently approved point-of-care Covid-19 diagnostic tests, such as Abbott ID NOW and Cepheid GeneXpert, require specialized and expensive instrumentation and technical expertise, limiting widespread use. Abbott’s has also been plagued by false negatives, meaning it sometimes fails to detect the coronavirus.

STOP stands for “Sherlock Testing in One Pot.” It builds on Zhang’s 2017 CRISPR invention, called Sherlock. Like the better-known, genome-editing versions of CRISPR, Sherlock starts with a guide molecule that homes in on a specific stretch of DNA — or RNA, which constitutes the genome of the new coronavirus. An enzyme called AapCas12b, from the bacterium Alicyclobacillus acidophilus, cuts the RNA in a way that generates a fluorescent signal detectable much as home pregnancy tests detect the presence of a pregnancy-related hormone.

For STOP, the scientists targeted their guide molecule at the coronavirus’s N gene, which codes for the nucleocapsid, or shell, that encloses its genome. The PCR test developed by the Centers for Disease Control and Prevention also targets the N gene.

The MIT scientists tested STOP on nasopharyngeal swabs from Covid-19 patients and on saliva samples from healthy people to which the new coronavirus was added. STOP had 100% specificity — it never “found” the coronavirus if the microbe wasn’t really there — and 97% sensitivity, meaning if the virus was present, the test missed it only 3% of the time. The existing PCR test misses up to 30% of cases, scientists have said.

The scientists have prepared enough material so far for 10,000 tests, and are making it free to researchers who want to evaluate its potential diagnostic use.

More detail on this detection method is found here:

captainmorgan said:

Scientists say a now-dominant strain of the coronavirus could be more contagious than original

A mutation in the novel coronavirus has led to a new strain viewed as more contagious than the virus that emerged from China, according to a new study.

www.latimes.com

Click to expand...

Evolution at work, the one that spreads best survives, that could also mean it is less virulent and produces more asymptomatic cases and possibly less deaths. Sometimes these things attenuate like this when containment measures are taken, the stealthy often less harmful strains can spread if they are asymptomatic. If they are slow to show up at the hospitals after infection, it would be a good indicator, but I'm sure people are keeping a close eye on it, there's not shortage of research grants for this shit and they are piling on!

The coronavirus has mutated and appears to be more contagious now, new study finds

The coronavirus that emerged in Wuhan, China over four months ago has since mutated and the new, dominant strain spreading across the U.S. appears to be even more contagious, according to a new study published.

The new strain began spreading in Europe in early February before migrating to other parts of the world, including the United States and Canada, becoming the dominant form of the virus across the globe by the end of March, researchers at the Los Alamos National Laboratory wrote in a 33-page report published on BioRxiv last week.

If the coronavirus doesn’t subside in the summer like the seasonal flu, it could mutate further and potentially limit the effectiveness of the coronavirus vaccines currently being developed by scientists around the world, the researchers warned. Some vaccine researchers have been using the virus’ genetic sequences isolated by health authorities early in the outbreak.

“This is hard news,” Bette Korber, a computational biologist at Los Alamos and lead author of the study, the Los Angeles Times said she wrote on her Facebook page.

“But please don’t only be disheartened by it,” she continued. “Our team at LANL was able to document this mutation and its impact on transmission only because of a massive global effort of clinical people and experimental groups, who make new sequences of the virus (SARS-CoV-2) in their local communities available as quickly as they possibly can.”

The study has yet to be peer-reviewed, but the researchers noted that news of the mutation was of “urgent concern” considering the more than 100 vaccines in the process of being developed to prevent Covid-19.

In early March, researchers in China said they found that two different types of the coronavirus could be causing infections worldwide.

In a study published on March 3, scientists at Peking University’s School of Life Sciences and the Institut Pasteur of Shanghai found that a more aggressive type of the new coronavirus had accounted for roughly 70% of analyzed strains, while 30% had been linked to a less aggressive type. The more aggressive and deadly strain was found to be prevalent in the early stages of the outbreak in Wuhan — the Chinese city where the virus first emerged.

The Los Alamos researchers, with the help of scientists at Duke University and the University of Sheffield in England, were able to analyze thousands of coronavirus sequences collected by the Global Initiative for Sharing All Influenza, an organization that promotes the rapid sharing of data from all influenza viruses and the coronavirus.

To date, the researchers have identified 14 mutations.

The mutation impacts the spike protein, a multifunctional mechanism that allows the virus to enter the host.

The research was supported by funding from the Medical Research Council, the National Institute of Health Research and Genome Research Limited

Why COVID-19 kills some people and spares others. Here's what scientists are finding.

The novel coronavirus causing COVID-19 seems to hit some people harder than others, with some people experiencing only mild symptoms and others being hospitalized and requiring ventilation. Though scientists at first thought age was the dominant factor, with young people avoiding the worst outcomes, new research has revealed a suite of features impacting disease severity. These influences could explain why some perfectly healthy 20-year-old with the disease is in dire straits, while an older 70-year-old dodges the need for critical interventions.

These risk factors include:
Age
Diabetes (type 1 and type 2)
Heart disease and hypertension
Smoking
Blood type
Obesity
Genetic factors

Why Economic Recovery May Depend On A Coronavirus Treatment

Both the government and the pharmaceutical companies are racing to develop a treatment to end the COVID-19 pandemic, and their new workflow might entirely change how the medical industry responds to pandemics forever

Applying SHERLOCK to SARS-CoV-2

Feng Zhang discusses applying SHERLOCK to SARS-CoV-2. This video, produced in February 2020, depicts details from the first version of the team’s SHERLOCK-based COVID-19 diagnostic.

This feature was filmed prior to new safety and social distance practices being instituted at the Broad.

Why Is This Virus So Contagious?

New mutation indicates that coronavirus might be weakening, study says

A mutation in the novel coronavirus mirrors a change that occurred in the genetically similar SARS virus in 2003 — indicating that the bug might be weakening, researchers announced in a newly published study.

Lead study author Dr. Efren Lim, an assistant professor at Arizona State University’s Biodesign Institute, and his team use a new technology called next-generation sequencing to rapidly read the genetic code of the coronavirus, referred to by scientists as SARS-CoV-2.

That technology helps researchers determine how the virus is spreading, mutating and adapting over time.

Out of the 382 nasal swab samples the researchers examined from coronavirus patients in the state, a single sample was missing a significant chunk of its genome. Eighty-one of the letters were permanently deleted, according to the new study published in the Journal of Virology.

“One of the reasons why this mutation is of interest is because it mirrors a large deletion that arose in the 2003 SARS outbreak,” Lim said in a statement.

During the middle and late phases of the 2003 SARS epidemic, the virus accumulated mutations that lessened its strength, according to the researchers.

“Where the deletion occurs in the genome is pretty meaningful because it’s a known immune protein which means it counteracts the host’s antiviral response,” Lim told the Daily Mail.

A weakened virus that causes less severe symptoms may get a leg up if it is able to spread efficiently through populations by people who don’t know they are infected, the scientists say.

However, it’s too soon to say whether the novel coronavirus is beginning to lose its potency, according to the researchers.

All of the patients whose samples the Arizona scientists analyzed had some clinical coronavirus symptoms — meaning that even the version with 81 deletions was still strong enough to make the patient at least somewhat sick, the Mail reported.

This is the first time such a deletion has been seen in the 16,000 coronavirus genomes that have been sequenced to date, according to the researchers.

That’s less than half a percent of the strains circulating, according to the scientists. There are about 3.6 million confirmed COVID-19 cases worldwide.

“This is a drop in the bucket,” Lim told the Mail.

“One sample is the convincing thing we need to say ‘Look at this,’ meaning that if more coronavirus genomes are sequenced, scientists might find far more instances of this attenuated genome,” he said.

Weakening lol, wishful thinking. My belief is two years of hell if we're lucky and no long lasting vaccine.

The scientific evidence on remdesivir so far explained clearly in plain english! He goes through the pros and cons of the evidence so far.
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Will Remdesivir Save The World From COVID?

A discussion of what remdesivir is, how it works against COVID (coronavirus/SARS-CoV-2), and what are the major takeaways from 3 relevant clinical trials (including the NIH's ACTT trial).
Gilead Press Release: https://www.gilead.com/news-and-press...
NIH Press Release: https://www.nih.gov/news-events/news-...
Chinese remdesivir trial in Lancet: https://www.thelancet.com/journals/la...

Here is why the SHERLOCK test above is so important, it's simple, cheap, fast, highly accurate and doesn't require the equipment or chemicals that this process requires. This shows you how complex the current process of RT-PCR virus testing is, see the above posts for details on the new SHERLOCK method of testing for covid-19. Want to know what the problems with testing are?
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Coronavirus real time RT-PCR Test - Animation video

I make animations in biology with PowerPoint, this animation video is about the standard coronavirus test, real time RT-PCR method, which is a laboratory technique combining reverse transcription of RNA into complementary DNA, and amplification of specific DNA targets using polymerase chain reaction (PCR).

Plasma Therapy Shows 'Promising' Early Results for Peoria COVID-19 Patients

Convalescent plasma therapy is showing some early signs of success as a COVID-19 treatment.

Dr. Teresa Lynch is interim department chair of internal medicine at the University of Illinois College of Medicine Peoria and a hospitalist at OSF Saint Francis Medical Center. She said outcomes from convalescent plasma therapy are "promising."

"We've seen patients get excavated or get taken off the breathing machines. And then one of the more promising things is we've seen clearance of the virus from the blood," she said. "Before we could detect the virus in the blood. The virus has become undetectable. And also seeing antibodies to the virus in the blood of patients who were treated."

The therapy uses donated plasma from recovered COVID-19 patients and transfuses it into patients currently suffering from the virus, in hopes antibodies in the plasma help the patient fight off the illness.

About a dozen Peoria-area patients have undergone convalescent plasma therapy.

Lynch is asking recovered COVID-19 patients to consider plasma donation. To qualify for donation, a positive COVID-19 patient must be asymptomatic for 28 days. One donor's plasma can treat up to three patients.

Mississippi Valley Regional Blood Center and the American Red Cross are working in conjunction with the Mayo Clinic to collect donor plasma from recovered COVID-19 patients for the treatment.

30 gravely ill Texas patients who underwent experimental COVID treatment are now recovered
John C Moritz Austin Bureau USA TODAY NETWORK, Corpus Christi Caller Times

It's is too soon to say for sure that the recoveries were aided by the therapy, but the doctor overseeing the treatment says it's a hopeful sign.

More than 30 gravely ill patients who took part in an experiments treatment for COVID-19 at Houston Methodist Research Institute have recovered from the illness and have left the hospital, the physician overseeing the therapy said Friday.

"All of these people were very, very sick," Dr. James A. Musser, chairman of the department of pathology and genomic medicine at Houston Methodist Hospital, said in a phone interview. "Many of them were on ventilators. That was the common theme."

It cannot be said with certainty the treatment in which plasma donated by people who had fully recovered from the illness caused by the contagious and sometimes deadly coronavirus and injecting it into those still sick was responsible for recoveries, Musser said.

But it appears to be a hopeful sign, he added.

"It's very, very early to know that," Musser said. "I think it's fair to say at this point that this is a safe strategy. That's always going to be question No. 1: Is this safe?

"And we can now say in pretty much a straight-forward fashion that yes, this is safe and we should proceed onward."

With no approved vaccine or proven treatment for COVID-19, Houston Methodist was among the first medical centers in the nation to get the go-ahead to conduct the therapy that has its roots in 19th-century medicine.

The treatment known as convalescent antibody therapy dates back to the 1890s. It "was the only means of treating certain infectious diseases" before more advanced treatments for viral outbreaks began emerging in the mid-20th century, according to a March 13 report in the Journal of Clinical Investigation.

Under the food and Drug Administration guidelines, the therapy will be used only on a case-by-case basis for people who are extremely ill and perhaps near death.

Some 200 former patients are now donors at Houston Methodist. About 20 people undergoing the therapy remain hospitalized.

Determining the procedure is safe is a step toward to expanding its use to others who might not be as sick as those who first received the therapy, Musser said.

Most of the people who received the therapy were older than average, and had underlying medical problems, he said.

Experts are still seeking to determine the types of patients who appeared to have benefited from the therapy and they types who did not.

How treating serious COVID-19 patients with antibodies from recovered donors could work

On Wednesday the Federal Health Minister announced an Australian biotechnology company is developing a potential new treatment for coronavirus, using plasma donated by people who have recovered from the disease.

This plasma is thought to contain high levels of protective antibodies that are able to fight off the virus.

CSL Behring Australian hopes to purify these antibodies and concentrate them to make a hyperimmune globulin product to give to patients with severe cases of the disease, who have not yet been ventilated.

While such antibody therapies might sound strange, they've been used in the past to treat diseases like Lassa fever, Ebola and swine flu.

We asked immunologist Larisa Labzin of the University of Queensland, to explain how such a treatment might work.

How antibodies help your immune system fight a virus
Viruses are unable to replicate without a host cell, Dr Labzin said, so getting inside our cells is their main purpose.

One of the ways our immune system fights them off is by trying to block their entry into the host cells.

"That's what antibodies are really, really good at, so they neutralise the virus," she said.

"It's like they handcuff the virus, and stop them being able to unlock the door to get in the cell."

These antibodies are produced by a type of our white blood cells known as a B cell.

These y-shaped antibodies can also act like flags on the virus and signal to other immune cells like macrophages — which are a bit like the garbage collectors of the cell — to get rid of the virus.

What you're looking for in a treatment
Scientists are looking for signs of antibodies that neutralise the virus, which is the best indicator that someone may be immune.

"And that's how [CSL] will expect [their treatment] to primarily work in being protective," she said.

This response is also the main way people measure whether a vaccine works.

But it doesn't work for all viruses.

With HIV for example, people make a lot of antibodies against it but they still get sick, so these antibodies aren't effectively neutralising the virus.

With COVID-19, we still don't have the full picture.

"We know that antibodies against COVID can neutralise the virus, but we don't know yet if that means having neutralising antibodies indicates that you're going to be immune," Dr Labzin said.

How CSL's approach is different
Last month, Canadian newspaper The Globe and Mail reported on the largest clinical trial in the world to date using plasma from people who have recovered from COVID-19.

Known as convalescent plasma, the technique takes whole plasma from a recovered person, and infuses it into another patient with the disease, in the hope it will reduce the duration or severity of their symptoms.

Trials with convalescent plasma will also be taking place in Australia.

But whole plasma can contain components that may be problematic, Dr Labzin said.

"We're going to have a whole host of other factors in our plasma apart from just antibodies, and they do lots of things," Dr Labzin said.

Of particular relevance to COVID patients are the coagulation factors in your plasma that help your blood clot, but can cause problems if that coagulation happens where it shouldn't, for example blood clots that are causing minor strokes or potentially increasing the risk of heart attacks.

"So there's a danger, in terms of just transferring over total patient plasma or serum, that you would accidentally be transferring over some of those components as well," Dr Labzin said.