(Buenos Aires, Argentina) – A study conducted by Argentina-based non-profit Fundación Infant has found that convalescent plasma could significantly reduce the need for oxygen support among patients over 65 years old experiencing mild COVID-19 symptoms. The trial used convalescent plasma, a component of blood rich in virus-fighting antibodies, obtained from volunteers that have recovered from COVID-19 infections. This evidence, published in the New England Journal of Medicine, suggests a new approach for the treatment of elderly patients before severe symptoms develop, addressing an important gap in currently available therapies.
Fundación Infant identified two key factors that are critical for convalescent plasma to be effective: it must be administered within 72 hours of the onset of symptoms, and the plasma should have a high concentration of antibodies. If these conditions are met, the treatment could decrease the possibility that patients will require oxygen by half. The results are especially relevant considering that the trial enrolled 160 patients aged 65 and above, including those with co-morbidities that put them at greater risk for Covid-19.
“The evidence that early administration of convalescent plasma treatment can improve outcomes for COVID-19 patients is important,” said lead investigator Dr. Fernando Polack. “There is a paucity of therapies today to prevent progression of mild cases to severe illness and no clear pathway for keeping these patients out of hospitals, where capacity continues to be stretched. Our results provide a roadmap for an early intervention among individuals at higher risk, allowing us to expect a better prognosis for patients while reducing the need for oxygen support and hospitalization.”
The potential of convalescent plasma for Covid-19 is particularly significant for low- and middle-income settings, as well as places where hospital capacity is limited. The treatment is relatively inexpensive, can be provided at outpatient facilities and does not require complex infrastructure. Also, convalescent plasma can be obtained from patients that recovered from COVID-19. The study found that 28% of all volunteers with a history of COVID-19 that donated plasma developed the high titers of antibodies required for the observed effect in this trial.
Passive immunization techniques like convalescent plasma treatments have been used for over a century, most recently during the Ebola, MERS and SARS outbreaks. The research findings that convalescent plasma treatments could successfully be adapted to treat certain Covid-19 cases demonstrate the method’s enduring relevance to controlling infectious diseases.
“Effective ways that can be made available quickly to prevent the hospitalization of COVID-19 patients are critical to saving lives because it will take some time for new vaccines to reach everyone who needs them,” said Dr. Keith Klugman, Director of the Pneumonia Program at the Bill & Melinda Gates Foundation, a primary funder of the study. “In addition to indicating the efficacy of a tool that could be implementable and affordable in lower-income countries, the study provides key insights about the immune response to Covid-19 that could help with development of other medical interventions.”
The study, which took place between June and October 2020, was randomized, double-blind and placebo-controlled, in which 160 patients underwent randomization: 80 received plasma and 80 placebo. An independent Data and Safety Monitoring Committee oversaw the study, and it was funded by a grant from the Bill & Melinda Gates Foundation and the Fundación Infant Pandemic Fund. Additional clinical trials to support the efficacy and safety of the treatment are ongoing.
Covid-19 has killed more than 1.8 million people worldwide and older adults are particularly vulnerable. The World Health Organization estimates that 75% of these deaths were in those aged 65 and older.