The Food and Drug Administration (FDA) Commissioner Stephen Hahn has walked back claims he made about the benefits of convalescent plasma against the coronavirus following a press conference with Donald Trump.
Scientists and health experts targeted Mr Hahan on Sunday evening after the press conference because the commissioner claimed convalescent plasma could save 35 out of 100 people who had Covid-19.
"I have been criticised for remarks I made Sunday night about the benefits of convalescent plasma. The criticism is entirely justified," Mr Hahn said in a series of tweets on Monday evening. "What I should have said better is that the data show a relative risk reduction not an absolute risk reduction."
Convalescent plasma, which has been used as a therapeutic method for other infectious diseases like Ebola, is relatively safe to use by doctors. But it has yet to be proven effective against the coronavirus.
The FDA issued an emergency authorisation for the treatment on Sunday, as Mr Trump labelled the therapeutic treatment a "truly historic breakthrough" in treating patients with the novel virus.
The authorisation was based on a study from the Mayo Clinic, the largest one to look into the benefits of convalescent plasma, that looked into its effects on about 70,000 people who used the treatment.
During the Sunday press conference, Mr Hahn reaffirmed the president's statement that the treatment was effective by saying, "if you are one of those 35 out of 100 people who these data suggest survive as a result of it, this is pretty significant."
This was slammed as misleading by health experts.
"I personally could've done a better job and should've done a better job at that press conference explaining what the data show regarding convalescent plasma," Mr Hahn told CBS This Morning on Tuesday. "I can assure the American people that this decision was made on sound science and data."
Concerns have risen that the FDA issued the emergency authorisation based on politics and pressure from the White House.
"We at FDA do not permit politics to enter into our scientific decisions," Mr Hahn said in a tweet. "This happens to be a political season but FDA will remain data driven. On behalf of FDA's 18,000 career employees, I want to reassure the American public about this commitment."
Some doctors, including the nation's top infectious disease expert Dr Anthony Fauci, have cautioned that more research is needed on convalescent plasma to treat Covid-19 before it is rolled out across the country.
Dr Francis Collins, the director of the National Institutes of Health (NIH) and Dr Clifford Lane also expressed scepticism over the emergency authorisation before the announcement.
Their reasoning was that a recent Mayo Clinic study did not provide enough data to prove the potential benefits, the doctors said.
"The three of us are pretty aligned on the importance of robust data through randomized control trials, and that a pandemic does not change that," Dr Lane said in an interview on Tuesday.
The FDA was prepared to issue the emergency authorisation for the therapeutic last week. But these efforts were stalled after multiple doctors and experts advised against it, arguing there was not enough research to back up its potential positive effects.
Then on Saturday, Mr Trump accused members of the FDA being involved in the "deep state" because they would not approve certain vaccines and therapeutics, like convalescent plasma.
"The deep state, or whoever, over at the FDA is making it very difficult for drug companies to get people in order to test the vaccines and therapeutics," he wrote on Twitter.
One day later, the FDA issued its emergency authorisation for the therapeutic.
Convalescent plasma takes the plasma from people who've previously had Covid-19 and put it into current patients. If the treatment goes as expected, the antibody-rich plasma should boost up the current patient's immune system and form antibodies to fight against the virus.
In the Mayo Clinic study, scientists found that patients who received plasma early into their treatment fared better than those who received it later. But the study lacked a control group and was not peer-reviewed.
Experts have said more data is needed to better determine if convalescent plasma could lower the mortality rate of coronavirus when used as a therapeutic treatment.
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