Plasma therapy offers a beacon of hope

25 April, 2021 12:00 AM printer

COVID-19 is rampant around the world and the number of infections and deaths from the virus are constantly increasing in the wake of the second wave. A number of vaccines have already been introduced against the deadly virus. But globally, many people have become infected after receiving the vaccine, and the question of effectiveness of a vaccine still lingers in the minds of many. However, despite getting vaccinated, many patients are still getting infected. As a result, doctors are now relying on Convalescent Plasma Therapy (CPT) to save the lives of critically ill patients.

The respiratory disease COVID-19, was first identified in China in December 2019. It starts with a fever followed by dry cough. After a week it leads to shortness of breath, making some patients needing hospital treatment. Recent studies have identified thousands of types of corona, as it is constantly changing its form and nature.

The World Health Organization (WHO) has approved a number of vaccines on an emergency basis to combat the COVID-19 epidemic. Notable among them are the vaccines developed by Pfizer and Moderna in the USA, and jointly by AstraZeneca and Oxford University in the UK. In December 2020, WHO authorised the emergency application of the Pfizer-BioNtech vaccine. But the Oxford-AstraZeneca vaccine is being hailed worldwide for being cheaper and easier to distribute than Pfizer or Moderna vaccines. In addition, a review by WHO states that the Oxford vaccine meets all the required safety standards, with its benefits outweighing the risks. Vaccines are approved by an internal panel of WHO. It is recommended that two doses be administered to all adults at intervals of 6 to 12 weeks. The vaccine is also effective against the South African corona variant. 

But despite being vaccinated, a patient may get infected. That is why many countries have continued to treat patients using different methods. Physicians have found success in treating coronavirus using a procedure which is called plasma therapy in medical terms, plasma being the aqueous component of the blood. Simply put, people who recover from corona have antibodies in their blood that make them immune to the virus. The plasma method means collecting plasma from the blood of cured individuals, then giving it to corona infected persons, so that antibodies develop in them.

Plasma is the fluid part of the blood, after all the red and white blood cells and platelets are removed. In CPT, plasma collected from a recovered person is transfused into the body of an infected patient. The plasma contains many essential proteins, blood clotting factors and immunoglobulins which are antibodies. The treatment given intravenously to the infected person with plasma is called CPT. Because this plasma contains antibodies and is collected from a recovered person to treat an infected patient, it is also called 'passive antibody therapy'.

So far, treatment of corona with Hydroxychloroquine, Azithromycin, Ivermectin, Favipiravir, Remdesivir, Plasma Therapy, etc. are being conducted in different parts of the world, although the WHO has approved several vaccines for the treatment of corona. However, it is important to keep in mind that none of the vaccines approved for treatment of COVID-19 are free from risk.

So far, CPT therapy is yielding promising results in trials. Though WHO has withdrawn plasma therapy from its medical policy on COVID-19, it stated that experiments may continue. The position of the US Food and Drug Administration (FDA) on plasma therapy is similar. The FDA of USA approved CPT on April 4, 2020, and on April 25, 2020 Clinical trials of CPT for treatment of COVID-19 patients were approved by the UK Government. Since it is experimental, it requires the written consent of the patient or the patient's legal guardian. It also needs to be clarified that it does not guarantee cure. CPT is not a completely new medical procedure. This medical system was first introduced in 1880 for the treatment of diphtheria.

In the beginning, plasma was collected from the body of an animal. Plasma is now collected from the human body. German physiologist Emile von Behring first introduced the idea of using plasma therapy. He won the first Nobel Prize in Physiology in 1901 for using plasma serum therapy against diphtheria. Later it was used in the treatment of scarlet fever in 1920. Until 1970, the treatment of whooping cough was given through plasma therapy. CPT was used as one of the medical procedures during the Spanish flu pandemic in 1918. Plasma therapy is also given for the treatment of measles, mumps, influenza and chicken pox. Although the results were of a mixed nature, CPT is by far the oldest treatment to fight COVID-19, most recently in 2003 with SARS, in 2009 with bird flu, in 2012 with Mars coronavirus, and most recently in 2013 with Ebola virus.

Anyone who has recovered from COVID-19 infection can be a potential plasma donor. A previously COVID-19 positive patient, after being tested negative twice in a row with no symptoms can be a plasma donor after at least 14 days (in some cases 28 days). Before donating plasma, it is important to have an antibody titer test to make sure that enough antibodies have been produced in the body. According to the policy of our country, 1: 160 titer is considered suitable for plasma therapy. Other conditions of blood circulation such as the presence of blood borne diseases (syphilis, malaria, hepatitis, HIV, etc.), plasma donor weight, blood pressure, pregnancy, etc. are also considered.

It is possible to take 400 to 500 ml of plasma from a donor's body at a time. It is possible to take only plasma without taking whole blood in a special process through an apheresis device. Up to three units (200 ml per unit) of plasma can be made from one donor's plasma. If the donor wants, he can give plasma again next week. After donating plasma, drinking three liters of water in 24 hours fills the gap. So there is no reason for the donor to be afraid.

A national subcommittee on plasma treatment was formed in Bangladesh under the Directorate General of Health Services (DGHS) in early April 2020, and on April 27 the Dhaka Medical College Hospital authorities decided to use CPT to treat corona patients. In this case, DGHS has been directed to supervise hospitals across the country. Many countries, including India, have already approved this treatment in the fight against COVID-19. This therapy has been successful in many countries of the world and it has also been experimentally successful in our country. However, it is very important to formulate a sound plasma policy for its successful implementation.

However, though no risk has been found in plasma therapy in particular, the risks involved in transfusion of blood or blood components apply. Concerned doctors say that there is no reason to be afraid to come forward for plasma donation. The more plasma available from donors, the easier it will be to deal with COVID-19 using CPT, and the brighter the hope of curing COVID-19.

 

Md. Zillur Rahaman, a Banker and Freelance

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