What Is Convalescent Plasma Therapy? Is It Effective To Fight COVID-19?

UPDATE: Convalescent plasma therapy is no longer recommended as a treatment method for COVID-19, according to new guidelines by the National Task Force of the Indian Council of Medical Research (ICMR) and experts from the Health Ministry.

This is because no significant benefits of plasma therapy were found in patients in reducing mortality and complications associated with COVID-19. Also, according to experts, the therapy may have played an important role in facilitating the mutation of the coronavirus.

What Is Convalescent Plasma Therapy (CPT)?

The CPT is a treatment method in which the antibodies of the recovered patients from COVID-19 is taken to treat people who are critically ill or have lower chances to recover from the same diseases. In this process, either the plasma or the whole blood from a recovered patient is taken. Usually, the active vaccination is administered to the patient so that their immune system can develop antibodies and fight against the pathogens. As there's no vaccine yet developed for COVID-19, passive antibody administration is the only way to treat critically ill patients immediately.

According to the journal The Lancet Infectious Diseases, a COVID-19 patient usually takes around 10-14 days to develop primary immunity against the virus. If the plasma is administered at an early stage, there are chances that the body will be able to fight against the pathogens and prevent them. [1]

COVID-19 And Convalescent Plasma Therapy

A study published in the journal JAMA on 27 March 2020 mentions the success of CPT on five critically ill patients with COVID-19. The five patients were confirmed with COVID-19 and have symptoms such as acute respiratory distress syndrome, severe pneumonia and high viral load. Even antiviral treatment and mechanical ventilation were not showing any positive results in their recovery.

Those patients then received CPT between 10-22 days from patients who have recovered from COVID-19. After the administration, their body temperature, serum antibody titer, viral load and other tests were carried out to measure the difference and view the outcome of the therapy.

Out of the five patients, three have been discharged while two were in stable conditions after the transfusion. The trial had shown unexpected improvement in the health of critically ill patients. This states that PCT has the potential effectiveness for COVID-19 treatment and can be considered in future to treat multiple patients. [2]

SARS And Convalescent Plasma Therapy

As aforementioned, the CPT has been used in many outbreaks before like SARS and Ebola. In a study conducted in Hong Kong among 80 SARS patients between March 20 to May 26, 2003, CPT has shown its efficacy and has treated all those patients who were given plasma before day 14. Those patients were also discharged from the hospital before 22 days. [3] Another study mentions about three patients from Taiwan, who when treated with 500 mL plasma, recovers with a reduction in their viral load. This shows that when CPT is carried out earlier, it is more likely to prevent the harmful agents in infected individuals.

How CPT Is Carried Out

This is a very quick process and just requires a collection of blood and an extraction of plasma. The process is carried out in either of the two ways:

• The whole blood is collected (350-450 ml) and then plasma is separated by a blood fractionation processor
• Plasma is directly extracted from the blood by using an apheresis machine, sending the remaining blood back to the donor.

Benefits Of Convalescent Plasma Therapy

• It can prevent infection in people who are either vulnerable or at higher risk of the disease.
• The process is effective in reducing the symptoms and mortality in patients.
• CPT is effective in preventing diseases rather than treating them.

Risks Of Convalescent Plasma Therapy

• Serum sickness due to the transfer of blood.
• Risk of transfusion-related acute lung injury in people with pulmonary diseases. [4]
• Risk of inadvertent blood transfusion or transfusion of blood that may contain other pathogens or to unmatched blood type.
• Risk of enhancement of other viral strain by the administrator of plasma which is just for one type of coronavirus.

Is CPT Effective To Combat COVID-19?

CPT cannot be addressed as an effective treatment for COVID-19 but it can be called supportive care for patients. There's also a question of whether the person will develop the same immunity against the virus or not. According to medical experts, CPT is to make sure that the infection does not go out of control in critically ill patients. The extent to which the CPT is effective is still unknown.

To Conclude

No exact cure for coronavirus has been discovered yet. Researchers and doctors are coming out with many experimental therapies to treat COVID-affected individuals.