Questions & Answers Regarding Convalescent Plasma and the Benefits in Treating Covid-19 Patients

What is Convalescent plasma?

Plasma collected from patients that have recovered from an infectious disease, referred to as convalescent plasma, can be used to manufacture immune globulin concentrates (plasma-derived medicinal products). Convalescent plasma therapy uses blood plasma from people who’ve recovered from an illness to help others recover.

Why is it helpful?

Blood plasma donated by people who’ve recovered from COVID-19 has antibodies to the virus that causes it. It is extracted in a process called plasmapheresis, performed with a plasmapheresis device where blood cells are first removed and then returned to the donor to separate only the plasma as a result of the procedure.

A study by the Mayo Clinic in the United States with more than 35 000 seriously ill patients  found that plasma can reduce mortality with 50 % if transfused within 3 days of deterioration and if the plasma has a high antibody titer.

Is there a risk for the donor?

It is important to know that when a person donates only plasma, it is much more sparing for his body than donating whole blood – plasma is 55% of the blood, 95% of which are water and only the rest are proteins, enzymes and also the antibodies. Plasma draining has many positive effects including anti-aging effect and extraction of toxins. It is good for the donor to take in more fluids and food rich in protein before the very donation.

How many people can you help with plasma donation?

Usually one person is providing 600 ml of plasma at one donation. This quantity is divided into 3 bags of 200 ml. If you have a high antibody titer, one donation can help 3 people! One person can donate plasma 3-4 times a month.

How often can I donate plasma?

According to the protocol, plasma can be donated once a week and up to 3-4 times a month without risk to the donor’s health. This means that 1 person can help many people, again only if he or she has high antibody titer.

Where you can donate blood plasma?

Currently there are two places in Sofia, one in Varna and one in Plovdiv where people can donate plasma. It is expected that in Stara Zagora and Pleven some special hospital wards will be open soon for donation of COVID plasma. The conditions for donation in the NCTH and the regional blood centers are the same. Only in NCTH the procedure is performed in one day. In all other places, the antibodies are tested first, and the donor is called the next day to perform the very donation.

What is required to donate plasma?
  • To be between 18 and 65 years old
  • To weigh at least 50 kg
  • You must have a document for a positive PCR test, which you carry on the spot at the NCTH; you can also show it on a digital device
  • At least 40 days must have elapsed since the date of the positive PCR test
  • The donor should have no comorbidities or take any regular medication
  • Make an appointment to donate blood plasma – between 5 and 10 days in advance
  • Carry an identity document

On the day of the donation, it is recommended that you have had breakfast, taken enough liquids. Coffee is also ok.

What is NOT needed?
  • To have a negative PCR test document or any other negative COVID-19 test
Can you donate blood plasma specifically for someone?

Yes. In the NCTH, you can give the names of the patient and the hospital where they are treated. You can even give up to three names, as three doses of convalescent plasma are released from one donor. The note you receive from the Blood Center must either be taken directly to the patient’s medical facility or photographed and sent directly to the treating physician/medical institution. From there, the medical establishments agree by administrative means, i.e., one side demands blood plasma, the other sends. As soon as possible.

Only the treating physician can send a request to the blood plasma center for a specific patient.

If you do not have a particular patient to donate for, your plasma goes to the plasma bank and then distributed to a patient in need.

When can plasma be donated again?

After at least a week of the already donated one. This process differs from normal blood collection because only plasma is extracted, and the blood cells goes back to the donor. That is why time between two donations can be much shorter – 2-3 days.

Do the people I donate need to be of my blood type?

It is recommended, but not required. Plasma is stored at the NCTH and other blood centers and depending on the blood type of the patients for whom it is donated, the required blood type is taken from there. If they don’t have one in stock at the moment, they wait, which can be fatal at times. That is why, it is good to have more and different donors – so that there are stocks available.

If a person close to you needs blood plasma

The treating physician should request plasma from the NCTH and other blood centers in the country, indicating the patient’s name and blood type. From there, they get an answer if there is plasma and when to send an ambulance to get it.


This information was prepared with the support of the “Association for Treatment of Covid-19 with convalescent plasma“.

Learn more about “Association for Treatment of Covid-19 with convalescent plasma” in Bulgarian here.

Association for Treatment of Covid-19 with convalescent plasma:

Sofia, 9 ‘Tri ushi’ fl.1; Tel. +359 89 878 0380; Email: [email protected] ; covid19plasma.eu ; Facebook

Banking details:

Association for Treatment of Covid-19 with convalescent plasma

Сдружение “Лечение на КОВИД-19 с реконвалесцентна плазма”

Bank account: IBAN BG 04 PRCB 9230 1051 53 92 01, ProCredit Bank (Bulgaria)


You can read the full EU programme of COVID-19 convalescent plasma for collection and transfusion – guidance on collection, testing, processing, storage, distribution and monitored use.