Convalescent plasma: What you need to know
Laymis Alvarez (R) takes blood samples from Heather Lieberman, 28, as she participates in a COVID-19 vaccine study at the Research Centers of America (RCA) in Hollywood, Florida, on August 13, 2020. So-called phase three vaccine clinical trials, in which thousands of people take part in the final stages, are gaining traction in Florida. With more than half a million cases and over 9,000 deaths, Florida ranks second in the US in total cases behind California, making it an ideal place to carry out the trials. That has led to a flurry of activity at the RCA, a private center carrying out clinical trials in Hollywood, 25 miles (40kms) north of Miami.
Convalescent plasma: What you need to know
Issam Ahmed (Agence France-Presse) - August 25, 2020 - 7:34am

WASHINGTON, United States — The United States has issued an emergency authorization to use blood plasma from recovered COVID-19 patients as a treatment against the disease.

Is it safe and effective? Has President Donald Trump's administration put political considerations ahead of the science? Here's what you need to know.

What is convalescent plasma?

When a person has COVID-19, their body produces antibodies that fight the coronavirus. These proteins float in plasma, the liquid component of blood.

The antibodies can be harvested from patients who have recovered and injected into the blood of others to help them fight the same infection. 

The idea isn't new -- so-called "passive immunization" -- was first tried out against diphtheria in 1892 and later against the 1918 flu pandemic.

Is it safe and effective?

The research into these questions is ongoing, but some early signs have been encouraging.

In June, the Mayo Clinic analyzed the safety of plasma following transfusion in a group of 20,000 COVID-19 patients, finding extremely low rates of side-effects such as heart failure, lung injury, allergic reaction and death.

"We concluded that the use of convalescent plasma was safe," Dr Scott Wright, who led the study that was published in Mayo Clinic Proceedings, told AFP.

Importantly, there was no sign of an effect called "antibody-dependent enhancement," when antibodies that aren't well suited to stopping a virus actually lead to more cells becoming infected.

On the question of how well it works, all experts agree on the need for more clinical trials to compare plasma against standard care.

Dr Soumya Swaminathan, chief scientist of the World Health Organization, said a few smaller trials have reported their findings but "the results, in some cases, point to some benefit, but have not been conclusive."

Another study by Mayo Clinic -- which was not a clinical trial and hasn't yet been peer-reviewed -- suggested plasma helped reduce death rates among hospitalized patients when given early and when the antibody levels were high. 

But there was no placebo, making it hard to read too much into the findings.

It enrolled 35,000 patients and showed that those who received transfusions within three days of their COVID-19 diagnosis had an 8.7 percent death rate in the next week. 

Those who received plasma after four or more days had an 11.9 percent death rate.

Researchers at Johns Hopkins University are meanwhile running a trial in which they are using plasma to immunize patients before they have a chance to get sick. 

Dr David Sullivan, who is leading this trial, compared it to an "immediate vaccine."

If it works, "we can tell people that if you're high risk... you can get this early, and you don't have to worry about going to the hospital," he told AFP.

Some scientists believe that while plasma might be useful right now, in the long-run it might be more advantageous to identify the best antibodies to COVID-19 then synthesize them in labs.

These are known as "monoclonal antibodies" and they are being developed by biotech firms including Regeneron and Lilly.

The advantages are that doctors know precisely what they are getting and can dose accordingly, and the drugs can be mass-produced.

On the other hand, since the virus is continually mutating, antibodies that were produced in a lab to fight an older version might not be as effective as recently-harvested plasma.

Was the authorization politicized?

The Food and Drug Administration (FDA) has previously issued emergency authorizations for antiviral remdesivir, after it was shown to have moderate efficacy against the coronavirus, and for the antimalarial drug hydroxychloroquine, which was subsequently reversed following safety concerns.

Political commentators have questioned the timing of the FDA's latest move as Trump lags in polls before the November election.

Indeed, in making the announcement, both Trump and FDA Commissioner Stephen Hahn misrepresented a key statistic when they said that plasma reduced mortality rates by 35 percent.

FDA spokeswoman Emily Miller later clarified on Twitter that the figure referred to the relative reduction in mortality risk for people who received high-levels of antibodies in the Mayo Clinic study compared to those who received low-levels.

"It does undermine the credibility of the entire United States government and the administration but specifically these institutions," said Dr Matthew Heinz, a physician in Arizona who served in former president Barack Obama's health department.

But Dr Daniel Hanley, who directs Johns Hopkins' multisite clinical trials, said that early results had met the threshold for emergency approval. 

"One thing to emphasize is this information is coming in faster than it has in any other pandemic," he told AFP.

As It Happens
LATEST UPDATE: November 26, 2020 - 8:31am

Follow this page for updates on a mysterious pneumonia outbreak that has struck dozens of people in China.

November 26, 2020 - 8:31am

The coronavirus pandemic is no excuse for not getting enough exercise, the World Health Organization says Wednesday, warning that even before the crisis many were getting too little physical activity. 

In an update of its physical activity guidelines, the UN health agency stressed that exercise was vital to physical and mental health, while sedentary behaviour can have serious repercussions.

"WHO urges everyone to continue to stay active through the Covid-19 pandemic," the agency's head of health promotion Ruediger Krech told reporters.

"If we do not remain active, we run the risk of creating another pandemic of ill-health as a result of sedentary behavior." — AFP

November 25, 2020 - 8:29pm

The coronavirus crisis has hit Italy's already historically-low birth rate, new projections from the national statistics agency reveal. 

Italy had last year already recorded its lowest number of births for 150 years, at 420,000, but this could fall to 408,000 in 2020 and 393,000 in 2021, according to Istat.

The projections were presented by Istat chief, Gian Carlo Blangiardo, to lawmakers on Tuesday.

"The climate of fear and uncertainty as well as financial difficulties... caused by recent events will have a negative effect on the fertility of Italian couples," he said. — AFP

November 25, 2020 - 6:13pm

Tokyo's governor on Wednesday urged residents to avoid non-essential outings and asked businesses serving alcohol to shut early as Japan battles record coronavirus infections.

The country has seen a comparatively small outbreak overall, with just over 2,000 deaths and 135,400 confirmed cases, and has not imposed the strict lockdowns seen elsewhere.

But it is now battling a third wave of the respiratory disease, reporting record numbers of daily infections nationwide in recent days.

"We'd like to ask Tokyo residents, if they can, to refrain from non-essential outings as much as possible to prevent further spread of infection," Governor Yuriko Koike told reporters. — AFP

November 25, 2020 - 4:18pm

The Department of Health reported 1,202 additional coronavirus infections Wednesday, taking the nationwide caseload to 422,915.

With 137 new positive cases, Davao City recorded the highest increase in infections. It was followed by Quezon City with 68 cases, Batangas with 59, Laguna with 54 and Cavite with 47. 

November 24, 2020 - 8:16pm

The novel coronavirus has killed at least 1,397,322 people since the outbreak emerged in China last December, according to a tally from official sources compiled by AFP at 1100 GMT on Tuesday.

At least 59,256,310 cases of coronavirus have been registered. Of these, at least 37,691,800 are now considered recovered.

The tallies, using data collected by AFP from national authorities and information from the World Health Organization (WHO), probably reflect only a fraction of the actual number of infections. — AFP

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