Among the few certainties left by this pandemic is that the acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of the coronavirus disease 2019, causes a particularly serious illness in older adults. The percentage of these patients who are hospitalized is high and the majority of deaths from COVID-19 worldwide occur in this age group.
Treatments for the early stages of the disease remain difficult to achieve. Few strategies provide benefits, several have failed, and others are being evaluated. One of them is convalescent plasma.
The paper published today in the prestigious scientific journal The New England Journal of Medicine and titled Early High Titer Plasma Therapy to Prevent Severe COVID-19 in Older Adults, to which Infobae was able to access shows the results of the study carried out by the team of scientists from the Infant Foundation, led by the Argentine infectologist Fernando Polack, and where the experts Romina Libster and Gonzalo Pérez Marc stand out as heads of the investigation.
Convalescent plasma administered to hospitalized patients has not been successful, perhaps because the antibodies must be given earlier in the course of the diseasethe researchers said in the study.
“We conducted a randomized, double-blind, placebo-controlled trial of convalescent plasma with high IgG titers against severe acute respiratory syndrome coronavirus 2 in older adult patients within 72 hours after the onset of mild COVID-19”They wrote.
The primary endpoint was severe respiratory illness, defined as a respiratory rate of 30 breaths per minute or more, an oxygen saturation of less than 93% while the patient was breathing room air, or both.
The trial was halted before reaching 76% of its projected sample size because COVID-19 cases in the trial region dropped significantly and constant patient enrollment became virtually impossible. It was held between June 4, 2020 and October 25, 2020 (when the last patient completed the follow-up). The trial was approved by the institutional review boards of the participating institutions and health authorities of the City of Buenos Aires and was supervised by an independent data and safety monitoring board.
Patients who were 75 years of age or older, regardless of current coexisting conditions, or between 65 and 74 years of age with at least one coexisting condition were identified and evaluated to determine their eligibility. Eligible patients had had at least one of each sign or symptom in the following two categories for less than 48 hours: a temperature of at least 37.5 ° C, unexplained sweating or chills; and dry cough, dyspnea, fatigue, myalgia, anorexia, sore throat, dysgeusia, anosmia, or rhinorrhea.
Those consenting to screening received home visits, and nasopharyngeal and oropharyngeal secretions were sampled for analysis with an RT-PCR assay (iAMP COVID-19, Atila BioSystems) to detect SARS-CoV-2. Patients with detectable SARS-CoV-2 RNA were transferred to the trial hospitals and invited to sign the informed consent form.
Convalescent plasma or placebo was administered less than 72 hours after onset of symptoms, and infusions of the serum were administered over a period of 1.5 to 2.0 hours. Both the convalescent plasma and the placebo were concealed with opaque bags and tape to cover the infusion catheter. Patients were monitored for adverse events up to 12 hours after the intervention.
They identified a total of 479 potential plasma donors who had had SARS-CoV-2 infection for a minimum of 10 days and who had been asymptomatic for 3 days or more and had two negative RT-PCR tests through hospital rosters. and an online campaign.
The clinical status of the patients was monitored daily by the trial physicians until day 15 to assess primary endpoint events that occurred in the hospital, participating geriatric institutions, or at home if patients had been discharged. .
A total of 160 patients were randomized. In the intention-to-treat population (i.e., the one initially assigned to be treated), severe respiratory disease developed in 13 of 80 patients (16%) who received convalescent plasma and 25 of 80 patients (31%) who received placebo (relative risk, 0.52, 95% confidence interval [IC ]0.29 to 0.94; P = 0.03), with a relative risk reduction of 48%. A modified intention-to-treat analysis that excluded 6 patients who had a primary endpoint event, prior to infusion of convalescent plasma or placebo, showed a larger effect size (relative risk, 0.40, 95% CI , 0.20 to 0.81). No solicited adverse events were observed.
Definitely, the researchers concluded: “Administration of convalescent plasma with high titers of IGg antibodies against SARS-CoV-2 to infected patients within 72 hours after the onset of symptoms reduced the risk of progression to severe respiratory disease by 48%”.
INFANT researchers noted in the NEJM paper: “Our trial has fundamental differences in design from previous randomized trials of convalescent plasma therapy in COVID-19 patients. For exampleWe focus on older adults because they are the most affected by the pandemic. Previous trials involved adults over 18 years of age. Furthermore, our goal was to stop the progression of the disease early and in a mild stage ”.
“Although our trial lacked the power to discern long-term outcomes, the convalescent plasma group appeared to perform better than the placebo group with respect to all secondary outcomes. Our findings underscore the need to return to the classical approach of treating acute viral infections early and define IgG targets that facilitate donor selection. “
Plasma with endorsement
Emil Behring received the first Nobel Prize in Medicine in history in 1901 precisely for his work in which he demonstrated that plasma could be used to treat diphtheria. In Argentina, the serum was well known due to the hemorrhagic fever epidemic that hit the country 70 years ago, and it was treated with convalescent plasma, having managed to reduce the lethality of the disease thanks to the outstanding work of Dr. Julio Maiztegui.
CWith the passage of time and scientific research, it was shown that the key component of plasma for the treatment of infections is antibodies. Antibodies are Y-shaped proteins that are highly specific for any infection that a person has previously encountered. They are produced in large quantities by the B cells of our immune system to bind to the invading virus and then attack it to destroy it.
Regarding the therapy with this convalescent serum and in dialogue with Infobae Fernando Polack advanced clearly and prior to the publication of the NEJM, “This study we carried out in Argentina describes the world’s first strategy to stop the progression of SARS-COV-2 with an inexpensive, universal, non-patent, proven safe intervention that can be administered on an outpatient basis in care units without the need for hospitalization. This research on early use of convalescent plasma in older adults over 65 years of age with mild COVID-19, among whom it demonstrated an efficacy of 61% in preventing the coronavirus from developing into a serious illness and evolving only, in the words of the specialist, in “a bad cold.”
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“The use of plasma transforms COVID-19 into a bad cold,” said Fernando Polack when presenting results of his scientific study
The infectologist Fernando Polack with Infobae: “Today it is no longer impossible to prevent or stop the coronavirus”
Convalescent Plasma: How It Works, What to Expect, and Other Questions About Promising Therapy to Treat COVID-19