Before the pandemic coronavirusexperts from all over the world are using the most advanced techniques to find a treatment against the disease Covid-19.
There is, however, a group that will bet on a technique that exists for more than a century.
It is the therapy with plasma convalescent, a procedure that has been tested during other pandemics and now a group of doctors is using to give hope to the people who run the risk of dying because of the Covid-19.
The principle is simple: make transfusions plasma of the blood of those who have already recovered from the disease to patients who are battling against it.
How does this technique work and why prestigious doctors and scientists believe that it might work?
To understand this treatment, it is important to first know what it is that makes it special to the plasma.
The plasma is the serum, or portion liquid that remains after you have removed the red blood cells, platelets and other cellular components of the blood.
This fluid contains water, salts, antibodies and other proteins, and is usually used in therapies for people with impaired immune system, hemophilia, or who have had trauma such as burns or bites from animals with rabies.
Before they discovered the antibiotics, the plasma was also a common treatment to combat bacterial infections.
There are records that during the 1918 flu pandemicmore than a thousand 700 people receive transfusions of plasma, but it is difficult to determine how effective they were based on the standards of medicine today.
How does it work?
When a person has an infection, your body reacts by creating antibodies to defend themselves.
Once the person recovers, these antibodies remain stored in the plasma for weeks or even years.
Therapy plasma transfusion convalescent is based on the fact that the sick receive the antibodies that beat the virus in another person.
The experts also call him “antibody therapy passive“because , instead of waiting for the agency to create its own antibodies, as occurs with vaccines, here it is about to flush his blood with a plasma that already has the has.
Why try now?
The technique of plasma-convalescent it has already been studied in outbreaks of other respiratory illnesses like SARS in 2003, H1N1 in 2009 and the of MERS in 2012.
The Food and Drug Administration of Usa (FDA, for its acronym in English) considers that the plasma convalescent is a treatment “promising“ and already authorised the use in patients of Covid-19 facing “threats severe or immediate for your life.”
The same FDA, however, refers to the plasma therapy as a “treatment in research“ “he has not shown to be effective in all diseases in which it has been studied”.
The agency, part of the Department of Health EUsays that it is important to do clinical trials to determine if the plasma convalescent is “safe and effective“ to treat patients of Covid-19and that is the task that is put a group of researchers in the country.
“The story gives us optimismbut we have to try that with the coronavirus,” he tells BBC World the doctor immunologist Arturo Casadevall, head of the Department of Molecular Microbiology and Immunology at the Johns Hopkins University.
Casadevall is the leader of a project that brings to 34 hospitals and universities in 17 states EU preparing to make clinical trials plasma convalescent patients Covid-19.
This project is based on receiving donations plasma of people who have already recovered from the disease.
Prestigious institutions as Johns Hopkins University, the Mount Sinai School of Medicine and the Mayo Clinic are involved in the project.
Tests and more tests
Although some hospitals in New York already began to apply plasma convalescent patients Covid-19, Casadevall warns that the most important thing is to make controlled, clinical trial.
The doctor refers to the fact that in the midst of pandemics has always used plasma, but they have never done tests in which we compare the results of those who receive the plasma with a control group that receives a placebo.
The members of the project are waiting for you in the next few days the FDA will of authorization to do these tests.
In countries such as United kingdom and Colombia also plans are underway to do controlled clinical trials with plasma-convalescent.
The results of these trials will serve to test the effectiveness of the technique, as well as to know if you have better results as preventive treatment, as something that should be done during the early stages of the disease, or as a last resort in severe patients.
It will also be key to respond to questions about the amount of antibodies needed, how long does it take the patients show a positive reaction, and how durable is the protection that might develop.
During this pandemic coronavirusChina already did studies that showed that the transplantation of plasma can be good results. These tests, however, were not conducted with a control group.
“It is not yet known if the plasma convalescent is effective for the Covid-19but there are isolated data they suggest that what might be”, tells BBC World the doctor immunologist specialist in transplant Joaquin Madrenas, scientific director of the Institute Lundquist, a member of the School of Medicine of the University of California in Los Angeles, where he is also professor.
“Given the uncertainty about the plasma recovering, its use is still considered experimental and this is why controlled studies are needed to demonstrate or refute its effectiveness,” says Madrenas.
Casadevall, for its part, warns that the results of these tests can take “several weeks“ and, though skeptical, has an optimistic tone.
“The history of the therapy of plasma da hopebut until we do the clinical trial, we will not have certainty.”
Now you can receive notifications of BBC World. Download the new version of our app and actívalas for do not miss our best content.