Doctors test whether survivors' plasma can prevent COVID-19 infection

Doctors are testing whether blood plasma from coronavirus survivors could PREVENT infection in people exposed to COVID-19

  • Plasma from the blood of coronavirus survivors contains immune cells including antibodies that may help fight off infection 
  • Thousands of coronavirus patients have been experimentally treated with plasma from survivors – but it’s not entirely clear if the treatment helps 
  • Doctors at Johns Hopkins University are now testing whether plasma may prevent infection in a 150-person clinical trial  
  • Here’s how to help people impacted by Covid-19

Scientists are testing whether blood plasma from coronavirus survivors could prevent the infection in others.  

Survivors of COVID-19 are donating their blood plasma in droves in hopes it helps other patients recover from the coronavirus. 

It’s still not entirely clear if or how much plasma from recovered patients boosts survival odds for those still fighting virus, but if it is preventive, it could be a huge untapped resource as the US fights to suppress a second wave. 

‘We have glimmers of hope,’ said Dr Shmuel Shoham of Johns Hopkins University, who is launching a study of 150 volunteers to find out whether the immune cell-rich plasma could prevent infection. 

Aubrie Cresswell, 24, of Delaware, is among the 20,000 American coronavirus survivors who have donated convalescent plasma. Now scientists hope plasma might prevent coronavirus infection as well as help to treat it

Thousands of coronavirus patients in hospitals around the world have been treated with so-called convalescent plasma – including more than 20,000 in the US – with little solid evidence so far that it makes a difference. One recent study from China was unclear while another from New York offered a hint of benefit.

With more rigorous testing of plasma treatment underway, Dr Shoham is launching a nationwide study asking the next logical question: Could giving survivors plasma right after a high-risk exposure to the virus stave off illness?

To tell, researchers at Hopkins and 15 other sites will recruit health workers, spouses of the sick and residents of nursing homes where someone just fell ill and ‘they’re trying to nip it in the bud,’ Shoham said.

It’s a strict study: The 150 volunteers will be randomly assigned to get either plasma from COVID-19 survivors that contains coronavirus-fighting antibodies or regular plasma, like is used daily in hospitals, that was frozen prior to the pandemic. Scientists will track if there´s a difference in who gets sick.

If it works, survivor plasma could have important ramifications until a vaccine arrives – raising the prospect of possibly protecting high-risk people with temporary immune-boosting infusions every so often.

‘They’re a paramedic, they’re a police officer, they’re a poultry industry worker, they’re a submarine naval officer,’ Shoham ticked off. 

‘Can we blanket protect them?’

The new coronavirus has infected more than seven million people worldwide and killed more than 400,000, according to official tallies believed to be an underestimate. 

With no good treatments yet, researchers are frantically studying everything from drugs that tackle other viruses to survivor plasma – a century-old remedy used to fight infection before modern medicines came along.

The yellowish, liquid component of blood, plasma (pictured) contains immune cells, including antibodies. Antibodies have the potential to both fight and block infection, so plasma from COVID-19 survivors may help prevent infection

Coronavirus has triggered a flurry of rapid research and development, but in some ways, it set the world back to pre-modern-medicine era. There are no proven treatments (although remdesivir seems to help) and no drugs to prevent it. 

Scientists are working at break-neck pace to change that. Hydroxychloroquine is also being studied as both a treatment and a preventive – and was taken for the latter purpose by President Donald Trump. 

WHAT IS PLASMA-DERIVED THERAPY? 

Plasma-derived therapy’ is based on the blood plasma of people who have recovered from the coronavirus.

Plasma is the liquid which carries blood cells, nutrients and hormones through the blood vessels, and makes up around half of all blood.

It also carries antibodies, which are proteins the body makes to destroy bacteria or viruses when they cause an infection.

If somebody has never been exposed to a virus or bacteria before – as is the case for everyone who catches the coronavirus – they do not have any antibodies and they become ill during the time it takes their body to make them.

Injecting them with antibodies from someone who has already made them saves time and helps the patient to fight off the illness faster.

So far, the evidence for hydroxychloroquine is not encouraging. 

Researchers at the University of Minnesota found that people treated with the malaria drug prophylactically were no less likely to catch coronavirus. What’s more, the drug comes with potentially dangerous heart side effects. 

Plasma, at least, has a long track record of safety, if not consistent efficacy.  

The historical evidence is sketchy, but convalescent plasma’s most famous use was during the 1918 flu pandemic, and reports suggest that recipients were less likely to die. 

Doctors still dust off the approach to tackle surprise outbreaks, like SARS, a cousin of COVID-19, in 2002 and the 2014 Ebola epidemic in West Africa, but even those recent uses lacked rigorous research.

When the body encounters a new germ, it makes proteins called antibodies that are specially targeted to fight the infection. The antibodies float in plasma – the yellowish, liquid part of blood.

Because it takes a few weeks for antibodies to form, the hope is that transfusing someone else´s antibodies could help patients fight the virus before their own immune system kicks in. One donation is typically divided into two or three treatments.

And as more people survive COVID-19, there are increasing calls for them to donate plasma so there’s enough of a stockpile if it pans out. 

In addition to traditional infusions, donations can be combined into a high-dose product. Manufacturer Grifols is producing doses of that ‘hyperimmune globulin’ for a study expected to start next month.

Convalescent plasma seems safe to use, Dr Michael Joyner of the Mayo Clinic reported last month.

His team tracked the first 5,000 plasma recipients in a Food and Drug Administration-sponsored program that helps hospitals use the experimental treatment, and found few serious side effects.

Not all plasma is equal. Scientists test vials of donated blood and plasma like these to see which are richest in antibodies 

Researchers at New York’s Mt Sinai Hospital compared each of 39 plasma recipients to four other COVID-19 patients who didn’t get plasma but were the same age, just as sick and being given the same amount of oxygen. 

People who received plasma before needing a ventilator were less likely to die than non-plasma recipients, said Dr Sean Liu, the study’s lead author.

‘We really tried to target patients who were early in their course, preferably within the first one to two weeks of their disease,’ Liu said.

‘Being a doctor during this time, you just feel helpless,’ Liu added, stressing that more rigorous study was needed but he was glad to have tried this first-step research. 

‘Watching people die is, it’s heartbreaking. It’s scary and it’s heartbreaking.’

His work has brought him some optimism about plasma treatment, but results of the first strictly controlled study were disappointing. 

Hospitals in the hard-hit Chinese city of Wuhan were comparing severely ill patients randomly assigned to receive plasma or regular care, but ran out of new patients when the virus waned.

With only half of the 200 planned patients enrolled, more plasma recipients survived but researchers couldn’t tell if it was a real difference or coincidence, according to a report in the Journal of the American Medical Association (JAMA) last week.

The real proof will come from ongoing, strict studies that compare patients assigned to get either survivor plasma or a dummy treatment.

Further complicating the search for answers, COVID-19 survivors harbor widely varying levels of antibodies. And while researchers want to use what Hopkins´ Shoham calls ‘the high-octane stuff,’ no one knows the best dose to test.

‘About 20 percent of recovered patients and donors have very strong immunity,’ estimated Dr Michele Donato of Hackensack University Medical Center, who is studying how long they retain that level of protection.

Those are the people researchers want to become repeat donors.

‘It’s, I think, our job as humans to step forward and help in society,’ said Aubrie Cresswell, 24, of Bear, Delaware, who has donated three times and counting.

One donation was shipped to a hospitalized friend of a friend, and ‘it brought me to tears. I was like, overwhelmed with it just because the family was really thankful.’

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