New research shows how the antibodies target different body parts of coronavirus in mild and severe cases.
- Antibodies against COVID-19 target different parts of the virus in mild and severe cases.
- The study was conducted by researchers from Stanford Medicine.
- SARS-CoV-2 binds human cells via spike protein which is a structure on its surface.
- The virus sheds its outer coat to reveal an inner shell that encases its genetic material.
- Once when the virus sheds, it creates multiple copies of itself and then is released to infect other cells.
- The antibodies prevent the infection by recognizing and binding to the spike protein and blocks to bind to the human cell.
- The antibodies that target other viral components prevent its viral spread.
- Researchers conducted a study on 254 patients with asymptomatic, severe, or mild COVID-19.
- During the study, 25 people died due to the disease.
- Patients with severe COVID-19 have a lower proportion of antibodies targeting the spike protein used by the virus to enter the human cells than of the antibodies targeting the proteins of the inner shell.
- The research analyzed three types of antibody levels called IgG, IgM and IgA.
- The proportions that targeted the viral spike protein or the inner shell, the disease progressed and patients either recovered or grew sicker.
- Researchers measured the levels of viral genetic material in nasal samples and blood from the patients.
- They assessed the effectiveness of the antibodies in preventing the spike protein from binding to the human ACE2.
- The research study shows that the severity of the illness correlates with the ratio of antibodies recognizing domains of the spike proteins compared with other non-protective viral targets.
- According to the research, a higher proportion of anti-spike antibodies was witnessed in patients with mild illness and those who died from the disease had more antibodies than recognized in other parts of the virus.
- Researchers raised concerns that the people can be re-infected, whether the antibody tests to detect prior infection are underestimated and whether vaccinations are needed to be repeated at regular intervals in order to maintain a protective immune response.
- This research is the most comprehensive study of the antibody immune response to SARS-CoV-2 across the entire spectrum of disease severity from asymptomatic to fatal.
- For the study, the researchers assessed multiple time points and the sample types and analyzed the viral RNA levels.