The world has shown several epidemics and pandemics across the past decades and centuries, like the Spanish Flu Pandemic in 1918, passing through several epidemics and pandemics till COVID-19 Pandemic in our era.
And the use of convalescent plasma to treat severe infections is not new; researchers studied its action to treat patients during Spanish Flu Pandemic, SARS-CoV-1 Epidemic, H1N1 Influenza Virus Pandemic, H5N1 Avian Influenza, and during Ebola Virus Outbreak in 2014.
In fact, convalescent plasma usually remains an option in many severe infections until we can find an effective treatment or a vaccine.
Convalescent Plasma and COVID-19
As soon as the patient recovers from COVID-19, his plasma—the liquid part of the blood—contains the antibodies of the virus.
Researchers suggest that if they transfer this plasma containing antibodies to another patient, who is still fighting COVID-19, it can shorten the length of the hospital stay, decrease the patient symptoms, and stimulates the patient’s body to form its own antibodies against COVID-19.
Shall We Consider Convalescent Plasma as an Effective Treatment for COVID-19?
Unfortunately, we have limited data regarding the use of convalescent plasma in COVID-19.
A small scale study was held in china: only five patients participated in this study. The five patients were on ventilators and received their antiviral regimens, besides methylprednisolone.
Within 3 days after the plasma transfusion:
- The body temperature of four patients has returned to normal
- A decrease in the viral overload in those patients
And within two weeks:
- The patients tested negative for COVID-19
- A decrease in the SOFA score (Sequential Organ Failure Assessment)
- Four patients have recovered from ARDS (acute respiratory distress syndrome)
- The physicians have removed three patients from ventilators
At day 37 (after plasma transfusion):
- The physicians discharged three patients from the hospital
- The other two patients were under stable conditions
Therefore, the patients have shown general improvement in their clinical status; however, we need further studies to prove the effectiveness of plasma to treat COVID-19.
Role of FDA in Using Convalescent Plasma to Treat COVID-19
FDA (Food and Drug Administration) has not approved the use of convalescent plasma yet.
On the other side, the FDA facilitates the use of the plasma for patients with serious conditions as an investigational drug, under the supervision of a licensed physician.
What are the specific criteria of the donor?
First, the donor must have completely recovered from COVID-19 (with no more symptoms) with a negative COVID-19 test. Plasma transmission occurs after two weeks of the patient’s recovery.
But before plasma transmission:
- Be sure that the patient has a sufficient amount of antibodies in his plasma: not to subject the patient to a decrease in his immunity, which may cause further re-infection with the virus
- Blood group matching is necessary before transfusion
- Screening of the donor against any infectious diseases
As soon as you collect the donor’s plasma, it can treat from one to three patients.
Despite the safety of convalescent plasma, some patients may experience any of these adverse effects:
- Allergic reactions
- Mild fever
- Acute lung injury
- Transfusion reactions
- Infectious disease transmission from the donor to the patient (very rare)
So till now, convalescent plasma is an experimental drug that we can use under the supervision of the FDA in life-threatening cases of COVID-19. And we need further clinical trials and studies to assure its effectiveness and safety. Maybe convalescent plasma gives us new hope to battle COVID-19 in our era!