Affected by the massive pandemic, Doctors and researchers are looking forward with Passive Immunization in order to save patients lives.
What is immunity?
Immunity is the natural ability of the body to resist a particular infection by the action of specific antibodies. They are produced in response to the foreign bodies that invade us including bacteria and viruses.
“A situation in which you are protected against diseases or from legal actions”
What is passive immunity?
It is defined as immunity which develops when any person receives immune components of the immune system from another person.
Types of passive immunity
There are 2 types of passive immunity:
● Naturally-acquired passive immunity
● Artificially acquired passive immunity
Naturally-acquired passive immunity
Naturally-acquired passive immunity is the transmission of antibodies from the mother to the child through the placenta, colostrum, and breastmilk.
Artificially acquired passive immunity
Artificially acquired passive immunity is done by injecting antibodies to an individual via vaccination.
Passive immunization
As Dr. Tahir Shamsi, Pakistan’s top hematologist and the head of the National Institute Of Blood Diseases, says, Chinese doctors have saved hundreds of lives with the help of this technique since February.
The respiratory illness caused by the novel coronavirus is the mystery that has killed nearly 10,000 people in the world and 448,656 people are sick worldwide today.
Blood (plasma) from recovered COVID-19 patients can be used to stop the spread of those contagious viruses.
Passive immunization is used when there is a high risk of infection and insufficient time for the body to develop its own immune response, or to reduce the symptoms.
Convalescent plasma therapy…what is it? And how do people recover from it?
Head of WHO’s Health Emergency Program said; “Convalescent plasma therapy has been found effective and life-saving against COVID- 19 and other infectious diseases, including rabies, Ebola and diphtheria.”
Pneumonia induced by the SARS-CoV-2, named coronavirus disease 2019 (COVID-19), which originated from the seafood market in the central city of Wuhan, China, has become a major concern all over the world. No specific treatment has been found to be effective for COVID-19, apart from supportive care like oxygen supply and intravenous remdesivir.
While there is no authentic treatment and vaccine available for COVID-19, whole blood collected from the surviving patient is used as an empirical treatment from which RBCs are separated and plasma is used as treatment.
Plasma therapy
Wuhan Hospital is the first who use convalescent plasma therapy to cure the patient and first tested 10 infected patients, out of which 6 survived. Many studies show shorter hospital stay and decrease the mortality rate in a patient treated with convalescent plasma than those who were not treated with this therapy.
This therapy was also recommended by WHO in 2014 as a treatment for ebola virus, and the same protocol used in 2015 as a treatment of middle east respiratory syndrome coronavirus. A pandemic 2009 influenza A H1N1 (H1N1pdm09) virus infection also shows a significant reduction in the risk of mortality in the patient who was treated with convalescent plasma therapy.
After meta-analysis by Mair-Jenkins and colleagues, it shows a reduced mortality rate after receiving the various doses of convalescent plasma in patients with the severe acute respiratory syndrome with no side effects and complications.
How does plasma help fight with the virus?
Currently, we don’t have any proven vaccinations or therapies to fight this disease. This vaccine works by training the immune system to recognize pathogens – either viruses or bacteria by creating antibodies in the blood.
When the pathogens enter the body, the antibodies are already present in the blood containing convalescent plasma to fight it off.
Is passive immunization helpful for the patients in ICU?
Yes, it works for the patients in the ICU. We immediately use this therapy on ICU patients for early recovery as Dr. Tahir Shamsi said in his interview.
What is convalescent plasma therapy?
It is an empirical treatment during outbreaks. Convalescent (person who is recovering from illness) plasma therapy is the technique in which plasma or immunoglobulins from recovered patients transfused to infected patients.
Plasma-antibody is separated from the blood by a centrifugation process, in which centrifugal force is used to separate the blood component using a device called the separator.
Steps that you should consider
Some steps that should be required while collecting convalescent plasma are;
● Identify a suitable patient recovered from COVID-19 as a potential blood donor
● Donor’s information and consent should be filled
● Donor’s blood grouping and screening for transfusion transmissible infection (TTI) should be seen
● Good care should be provided before, during and after the donation procedure
● Label the bag and store
How is it relevant to COVID-19?
Researchers reported that 3BNC117-mediated immunotherapy has broad neutralizing antibody to HIV-1, which increases the host humoral immunity to HIV-1.
Is this therapy safe and valid?
WHO declared plasma therapy as a very valid approach, but it is very important to get the right timing to maximize the boost to a patient’s immunity.
Difference between active immunity and passive immunity
You can differentiate between active immunity and passive immunity based on 5 easy to understand differences.
● Active immunity is produced in a person’s own body by contact with pathogen or antigen.
● Whereas, passive immunity is produced for the antibodies obtained from other outside sources.
● Active immunity takes time to develop, whereas passive immunity is developed immediately.
● Active immunity lasts for a long time, whereas passive immunity lasts for 2 to 4 days.
● Another difference is that active immunity has few side effects, whereas passive immunity reacts to antisera initiation known as serum sickness.
Take Away!
Passive immunization can save COVID-19 patients by incorporating immune system components from outside the body. Chinese doctors use this therapy to save COVID-19 patients.