A Series of Articles on the Science Behind COVID-19
All About the Serum – Your Guide to Convalescent Plasma Therapy
By: Ahmad M. Rashid, MD, pulmonary and critical care physician, National Jewish Health
September 1, 2020
What is convalescent plasma?
Plasma is the pale liquid running through your body in which your blood cells swim.
- People who recover from infections (viral and others) usually have antibodies in their blood against such infections
- Scientists in the late 19th century found that these antibodies persist in such patients’ plasma
- Giving a recovered patient’s plasma to a patient sick with a similar infection, the antibodies neutralize the infection and help people recover quicker
Has plasma been used before?
- Such plasma has been used for various infections since late 1800’s
- First widespread use in a viral pandemic was recorded in 1918 Influenza pandemic
- Used to treat various virus outbreaks that do not have effective medicine including the Polio epidemic in early 20th century, Hanta Virus outbreak during the Korean war, and more recently for viruses such as Ebola
What about against coronavirus?
- Studies done in China during the first SARS pandemic in 2003 showed generally patients did better if they received plasma early
What do we know about plasma therapy in COVID-19?
As early as March 2020, small studies came out of China that showed a “possible benefit” of treating COVID-19 patients with convalescent plasma.
Similar small studies in Houston and New York City showed, that some very ill patients could benefit from convalescent plasma therapy.
Enter the U.S. government – and Mayo Clinic
- FDA and Mayo clinic recommendations based on these data came up with the “Expanded Access Program”
- Thousands of patients across the U.S. have received this therapy in the last three months
- Preliminary data is posted online, but is awaiting review
- More than 35,000 patients in hospitals received plasma therapy
- They found that about 8 percent of the patients receiving plasma within three days of diagnosis died, this risk of death jumped to about 12 percent in patients who got the infusion after day four
- This is the origin of the 35% benefit!
- They also found that if donor plasma had higher concentration of antibodies there was greater benefit
What do we know so far?
- Convalescent plasma therapy is safe
- It may benefit select patients who are in the hospital
- Better results happen the earlier the treatment is given
- Higher antibody concentration in donor plasma may provide better results
What we do not know?
- Which particular patients will benefit the most?
- When is the best time to give it?
- What is the optimal dose?
- Should people get repeat transfusions?
In the coming weeks and months we will get answers to those questions. One thing is clear from our experience with this disease-there is no single magic bullet.
Convalescent Plasma is another valuable tool for the frontline providers to use for our sickest patients.
Interested in donating plasma?
If you are fortunate enough to have recovered from COVID-19, please go and donate plasma. People are battling for their lives, and they will be very thankful.
Donate Your Plasma
Colorado COVID-19 Convalescent Plasma Project Consortium
National COVID-19 Convalescent Plasma Project