Protective resistance against COVID-19 was shown to be strong in a recent study.
As a new hospital admission for people with COVID-19 continuing to decline (1), many locations are beginning to ease restrictions and restore normal life. Safety in COVID-19 increased due to vaccination and natural resistance after infection. However, questions remain as to how long any resistance will last (2).
In healthy adults, resilience is achieved no matter what infection occurs-either by vaccination or by natural illness (3). Doctors classify resistance as acquired or natural. Vaccination and antibody transfer result in acquired resistance, while infection / recovery and genetic transfer, such as through breastfeeding, result in natural resistance (4).
Depending on the type and severity of the infection, resistance can be strong or weak (4). Early in the COVID-19 pandemic, research suggested that natural resistance to COVID-19 lasted two to three months (5). This causes concern that the natural resistance of patients with low COVID-19 may later be affected as well.
To determine if a small amount of COVID-19 infection develops long-term resistance, researchers from the Washington University School of Medicine in St. Louis. -19 (6).
During an infection, the body attacks antigens through a variety of means. Initially the body’s natural immune response sends immune cells to surround and kill antigens of any kind of infection.
Subsequently, the adaptation of the body’s resistance response creates B-cells that produce high levels of antibodies specially designed to fight the antigen, and T-cells to attack the infected cells. B-cells also produce plasma cells that produce antibodies.
Some of the B- and T-cells become memory cells that recognize the antigen (7). Long -term plasma cells also remain in the bone marrow of the body releasing low levels of antibody to guard against future infection (6).
There are different types of antibodies that serve different activities. One is immunoglobulin G (IgG), which binds to microbes and accelerates their entry into the immune system (4). The other is Immunoglobulin A (IgA), which is concentrated in mucosal membranes and guards the body against infection (4).
In the study, blood samples were collected one, four, seven, and eleven months after the onset of COVID-19 symptoms. Brain samples were also taken from eighteen patients seven to eight and eleven months after infection.
Blood samples were examined for the presence of COVID-19 IgG, IgA, and bone marrow plasma cells (BMPC). In samples taken in the first few months after infection, IgG and IgA levels were high, as expected. In later samples, antibody levels dropped and lowered in most patients.
Seventy -nine percent of the BMPC samples contained antibody -producing cells, and the level of memory B cells was as seen in influenza patients. The study suggested that the immune response to COVID-19 follows the normal immune response (6).
The study has some limitations, however. The researchers did not find BMPCs in the four samples, suggesting the level of the cells to be lower than the threshold of detection. Also, most of the patients studied experienced small cases of COVID-19. It is not known whether the response is different for more severe COVID-19 infection.
Regarding severe infections, the first author Dr. Jackson Turner said in a press release, “It can go either way. Inflammation plays an important role in severe COVID-19, and excessive inflammation can lead to poor resistance responses. But on the other hand. part, the reason why people get sick all the time is because they have a lot of viruses in their bodies, and there are a lot of viruses around that can bring about a good resistance response.So it’s not clear. We need to copy the study of people with moderate to severe infections to understand if they are likely to be protected from the start as well. ”
- CDC. COVID Data Tracker. Centers for Disease Prevention and Prevention. Published March 28, 2020. Accessed May 26, 2021. https://covid.cdc.gov/covid-data-tracker/#new-hospital-admissions
- Goldberg C, Pollak A. Bloomberg – A robot? www.bloomberg.com. Published May 24, 2021. https://www.bloomberg.com/news/newsletters/2021-05-24/what-does-covid-immunity-look-like
- Dinerstein C. Is Safety or Vaccination Better? American Council on Science and Health. Published March 19, 2021. Accessed May 26, 2021. https://www.acsh.org/news/2021/03/19/natural-immunity-or-vaccination-better-15409
- US HEALTH AND HUMAN RESOURCES, NATIONAL INSTITUTES OF HEALTH, National Institute of Allergy and Infectious Diseases, National Cancer Institute. Understanding the Immune System How It Works. NIH; 2003. Accessed May 26, 2021. http://www.imgt.org/IMGTedukasyon/Tutorials/ImmuneSystem/UK/the_immune_system.pdf
- High QX, Tang XJ, Shi QL, et al. Clinical and biological analysis of asymptomatic SARS-CoV-2 infections. Natural Medicine. 2020; 26. doi: 10.1038 / s41591-020-0965-6
- Turner JS, Kim W, Kalaidina E, et al. SARS-CoV-2 infection induces longevity of plasma cells in the human brain. Nature. Posted online May 24, 2021. doi: 10.1038 / s41586-021-03647-4
- Bucher K. The Immune Response. Opened May 26, 2021. https://cdn.jamanetwork.com/ama/content_public/journal/jama/933829/jpg150012fa.png?Expires=1625020944&Signature=UbxiAQKTEPEWiPzg3EkfPoZFHGriCBCcQ1ws9VnY0E1D1cehI493KsHKmb3r6vL51r80yyNuGbvxrD91nmMtIou1Ybzwvv~Xlr0CvE-~oygqheGGU~o6wayTIISHrY~rk8M-OoxSuOEAy2px0oC93Z2KfJtEcU1Jeh16XCYQ4k8GPUIMFkmIN3kwydjNjjbaIATTrnUXgxniCCwlN3XAeDAwCfFPl9KgjrYgHyQvj8-M28jv8a6TaBQOk0ZSJgJYfVpFvrbwd1xn-- 7QUq8Ywbo4OlV2KJ2jeNERUZwQ8Norw1-rYOac-lLml4aUOICInU5-SuLW3wI2gjtzNn6Rdw __ & Key-Pair-Id = APKAIE5G5CRDK6RD3PGA
- Photo by Gerd Altmann from Pixabay