How long does convalescent plasma immunity last?
(CNN) - The US Food and Drug Administration (FDA) issued an emergency use authorization for convalescent plasma as a covid-19 treatment on Sunday, saying that " known and potential benefits of the product outweigh the known and potential risks of the product.
The FDA claims that more than 70,000 patients have been treated with convalescent plasma, made from the blood of people who have recovered from coronavirus infections.
"Today I am pleased to make a truly historic announcement in our battle against the China virus that will save countless lives," President Trump said at a briefing at the White House. "Today's action will dramatically increase access to this treatment."
Last week, Trump accused some health officials of making policy in the country regarding the emergency use authorization (EUA) of convalescent plasma. When asked about the FDA and the non-authorization of emergency use, Trump said the reason was political.
On Sunday, a source close to the White House coronavirus task force told CNN that the FDA had reviewed additional data to inform its imminent US decision. This official has not personally reviewed the data. They added that the FDA has no obligation to consult anyone outside the agency about its decision.
Convalescent plasma is taken from the blood of people who have recovered from COVID-19. In late March, the FDA laid out a path for scientists to test convalescent plasma with patients and study its impact. It has already been used to treat more than 60,000 patients with Covid-19.
However, like blood, the convalescent plasma supply is limited and must come from donors. And while there are promising signs from some studies, there is still no data from randomized clinical trials on convalescent plasma to treat COVID-19. Some of those trials are underway.
He survived the coronavirus and has donated 3 liters of plasma 3:25Impact of a USA
The New York Times reported last week that an FDA emergency use authorization for blood plasma to treat COVID-19 was suspended following intervention by NIH officials. The suspension came after a group of federal health officials, including the director of the National Institutes of Health, Dr. Francis Collins, the director of the National Institute of Allergy and Infectious Diseases, Dr. Anthony Fauci and Dr. H. Clifford Lane, deputy director of the NIAID, interceded to argue that the emerging data on the treatment was too weak, the Times reported Wednesday, citing two top administration sources.
In response to CNN, Dr. Anand Shah, the FDA's deputy commissioner for medical and scientific affairs, said he could not comment, but suggested that the NIH was misplaced.
"In general, the NIH is not involved in the decision-making process at the FDA and does not have all of the confidential data that the FDA uses to make these regulatory decisions," Shah said in a statement sent to CNN.
"We take seriously our mandate to follow the data and science on reviewing medical products to prevent or treat COVID-19 according to the legal and regulatory standards set by the agency," added Shah, noting that the FDA appreciated the work for the NIH and would collaborate with its sister agency.
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A senior administration official told CNN's Jim Acosta on Sunday that the expected emergency use authorization announcement is an important advance.
"If you are one of the 35 people out of 100 who survive severe covid symptoms due to convalescent plasma, this is certainly a breakthrough," the official said.
"And it is certainly an advance that over 5 months during a pandemic we have safety data based on 70,000 covid patients treated with convalescent plasma," added the official.
Ben Corb, director of public affairs for the American Society for Biochemistry and Molecular Biology, said in a statement that the president showed an "unwillingness" to listen to medical experts and that "progress requires data collection" to ensure the safety and efficacy of treatments.
"This process is necessary to ensure our safety and to ensure that a treatment is not worse than the disease," Corb's statement said. "I am deeply concerned about this action and concerned for the moment."
Demand for plasma 'exceeded anyone's expectations'
FDA emergency use authorization does not require the same level of evidence as full FDA approval, but it can have a significant effect on demand and use of a treatment during a public health emergency.
Dr. James Musser, chair of the Department of Pathology and Genomic Medicine at Houston Methodist, said an emergency use authorization could simplify the administration of convalescent plasma to patients with COVID-19.
"If they issue an AUS, my opinion is that this is a good thing for patients in the future," said Musser, who has studied convalescent plasma in COVID-19 patients. "But again, that will really depend on the parameters of the USA."
An EUA, which could open the treatment to more patients, could also have the effect of limiting enrollment in clinical trials that determine whether it is effective.
On Thursday, Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, noted that doctors have treated so many covid-19 patients with convalescent plasma that it has been difficult to find out if the treatment works.
"The problem with convalescent plasma is the great enthusiasm about it," Woodcock noted in an online conversation about the latest science behind monoclonal antibody treatments and convalescent plasma. "It exceeded anyone's expectations in terms of demand."
Woodcock, who has gone on to lead therapeutic efforts under the Trump administration's Operation Warp Speed, said the plasma has shown promise in early studies, but noted Thursday that there is still not enough evidence that it works.
His team counted 162 prospective studies and several more observational studies, but said only six met the standard that could produce actionable results. There are no data from randomized clinical trials yet, he explained, but some of those trials are ongoing.
"We continue to have evidence that this is an effective treatment for this particular virus," Woodcock said, adding that the NIH will initiate or push additional trials to find out for sure.
Even if this approach works, convalescent plasma has limitations.
“There is a limited group of donors; it goes away as the epidemic wears off, "Woodcock said. "It is not a standardized intervention and requires a compatible blood type for administration, which can be problematic in many settings."
CNN's Jim Acosta, Elizabeth Cohen, Jen Christensen, and John Bonifield contributed to this report.
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