BLOG: The immune system – our body`s defense


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Roughly, there are two parts to the immune system: the innate response and the adaptive response.

The first line of defense against foreign substances is the non-specific, innate immune response. It consists of physical, chemical and cellular defense mechanisms. The main purpose of the innate response is to immediately prevent the spread and movement of foreign pathogens throughout the body.

The second line of defense against pathogens is called adaptive immune response. Immune cells can produce antibodies against specific pathogens. Thus, the reaction is highly specific and effective. Its important goal is the creation of memory cells for long-lasting protection.

Spinal cord injury affects the immune system
Our immune system is located within many organs. Some are important for our body`s defense, like the spleen. The nervous system is controlling all our organs. Therefore, a paralysis, particularly above the 5th thoracic vertebra, can have a huge impact on immune function.  This phenomenon is called spinal cord injury-induced immune deficiency syndrome (SCI-IDS).

Vaccination is the best prevention
Vaccination is the most effective way to boost our immune system and to protect ourselves against pathogens. Vaccination also inhibits the spread of a virus amongst humans in an effective way.

If you successfully fight against a viral disease, your adaptive immune system will keep a memory of this specific disease. If you encounter the same disease again, your body will stop it in its tracks, keeping you from getting sick. Vaccination, also called immunization, relies on this immune memory by exposing the body to a virus in a weakened or killed state, or to its invalid toxins. This way the body will learn how to fight a disease without getting sick. This is called active immunization and will result in production of antibodies that are specific to the disease. In the case of a passive immunization the patient directly receives the antibodies that another person’s immune system created to fight the disease. This, of course, increases the chances of beating the disease, but does not provide long-term immunity.

COVID-19 Vaccination
Vaccines are currently being developed and tested. The World Health Organization (WHO) is predicting that a viable vaccine could be available in 12 to 18 months due to the massive worldwide effort.

Although you may find this time too long, it is much shorter than the average 15-20 years that pharmaceutic industries are calculating for bringing a vaccine to the market. Many steps are necessary to find the right type of vaccine, its ideal dosage and safely testing. Some people raised concerns that the virus will mutate much quicker and that a vaccine will come too late.

Due to the urgent need, efforts are also being put into passive immunization as an acute treatment for COVID-19 patients. They receive highly concentrated antibodies from people´s blood plasma that have already beat the disease. However, that will not create immunity, so active immunization may still be needed.

Herd immunity is the aim which could be achieved with two scenarios: either enough people have successfully fought the disease, or a viable vaccine will bring immunization.

The good news is that recent reports indicate that patients are indeed developing an immunity to the disease. However, nothing tells us how long this immunity can last. It also remains uncertain if a developed vaccine for people with a healthy immune system will have the same effect for SCI patients and other people with a compromised immune system.

Spinal cord injury and COVID-19
Medical doctors still have to gain experiences about COVID-19. They are analyzing how the virus is affecting healthy people and patients with spinal cord injury.

Until a vaccine is available the same recommendations are valid for people with a healthy or a compromised immune system. Thus, the most effective measures are a good hygiene and social distancing. 

Vieri Failli is a doctor of neuroscience that has a passion for bringing the general public closer to the most complex questions of science
Vieri Failli is a doctor of neuroscience that has a passion for bringing the general public closer to the most complex questions of science 

 

Souces:
https://www.vfa.de/de/arzneimittel-forschung/woran-wir-forschen/impfstoffe-zum-schutz-vor-coronavirus-2019-ncov
Nguyen A, David JK, Maden SK et al. Human leukocyte antigen susceptibility map for SARS-CoV-2. J Virol. 2020 Apr 17.
Quan-Xin L, Bai-Zhong L, Hai-Jun D, et al.  Antibody responses to SARS-CoV-2 in patients with COVID-19. Nature Medicine April 29 2020.
Matricardi P, Dal Negro R, Nisini R. The First, Comprehensive Immunological Model of COVID-19: Implications for Prevention, Diagnosis, and Public Health Measures. Pediatric Allergy and Immunology 2020 (Preprint).
Righi G, Del Popolo G. COVID-19 tsunami: the first case of a spinal cord injury patient in Italy. Spinal Cord Ser Cases. 2020 Apr 17;6(1):22.