Faced with the speed of infection and the impossibility of containing the Coronavirus pandemic, the U.S. government has resorted to a desperate measure just before the opening of the Republican National Convention.
As explained by NBC News, last Sunday, the Trump administration announced the emergency use authorization (EUA) of convalescent plasma, a treatment still considered “potential” in the fight against COVID-19.
The U.S. Food and Drug Administration (FDA) explained that the decision was research-intended and based on “available scientific evidence.”
“The U.S. authorizes the distribution of COVID-19 convalescent plasma in the U.S. and its administration by health care providers, as appropriate, to treat suspected or laboratory-confirmed COVID-19 in hospitalized patients with COVID-19,” the government agency said in a statement.
However, although Health and Human Services Secretary Alex Azar promoted the U.S. as “a milestone in President Trump’s efforts to save lives,” the World Health Organization warned that “evidence it Works remains ‘low quality,'” according to Reuters.
“At the moment, it’s still very low-quality evidence,” Soumya Swaminathan, WHO chief scientist, told a news conference. “So we recommend that convalescent plasma is still an experimental therapy, it should continue to be evaluated in well-designed randomized clinical trials.”
According to Reuters, the evidence is “conflicting,” between one Chinese study that showed plasma from people who have recovered from coronavirus failed to make a difference in hospitalized patients, while another pooled analysis showed it could lower the risk of death.
Swaminathan added another challenge: plasma’s variability, since it is drawn from many different people, produces a “less-standardized” than monoclonal antibodies crafted in the lab.
World Health Organization senior adviser Bruce Aylward added that there were also potential safety risks that must be vetted beyond plasma’s efficacy.
“There are a number of side effects,” Aylward said, ranging from mild fevers to severe lung injuries or circulatory overload. “For that reason, the clinical trial results are extremely important.”
How does it work?
According to NBC, convalescent plasma is an antibody-rich blood product taken from patients who have recovered from COVID-19. In theory, infusing the antibodies into a sick patient would “boost the person’s immune system” to fight the virus.
However, the scientific results are not conclusive.
Although preliminary tests at the Mayo Clinic on 70,000 COVID-19 patients have “certainly met the threshold” for a EUA, the treatment’s actual definitive effect has yet to be discovered.
How can treatment be accessed?
As NBC continues, the authorization allows the FDA to “reduce the paperwork” needed to obtain the plasma for patients, but this does not imply that it will be “widely available” or easily accessible.
The process of donor selection, the antibody load on each donor, and the eventual effect that can be obtained remain a matter of conjecture.
The only definitive solution to the crisis, as explained by Dr. Todd Rice, associate professor of medicine at Vanderbilt University Medical Center in Nashville, is the vaccine.
“We have found that people who have more severe symptoms tend to have higher concentrations” of antibodies, Rice said. He said the trial, which is expected to enroll up to 1,000 patients, is likely to continue despite the UEA. But it’s unclear whether efficacy data for plasma as a treatment will be available before a vaccine is approved.
“The fact is that our way out of this pandemic is with the vaccine,” Rice said. “The sooner we get a vaccine, the better off all of us are going to be.
What are the risks?
As Michelle Roberts, BBC’s health editor, explained, the FDA’s decision is “a balance of risks.”
While convalescent plasma has been effective in treating other diseases, including Ebola, recent studies have identified several unwanted side effects, including harmful allergic reactions.
In a statement, the Infectious Diseases Society of America said that while there were “some positive signals that convalescent plasma can help treat individuals with COVID-19…. we lack the randomized controlled trial data we need to better understand its utility in Covid-19 treatment”.
Jonathan Reiner, a professor of medicine at George Washington University, called it “a political stunt.”
“Convalescent plasma may have some efficacy, but we need to have definitive data,” he wrote on Twitter.