Question

At the beginning of spring break Stan went to a conference in Seattle and on Monday afternoon there was a reception for the lecturers. Nobody was social distancing yet.
Describe ALL the ways Stan's immune system was working to keep him from getting Covid19, even if he was exposed to the new Corona Virus. (Talk about how your immune system works to fight off a virus like covid-19)

Answer 1

Non-specific immune system or Innate immune system are an important first line of defense against viral infections. They are released by host cells in response to the presence of pathogens such as viruses, Interferons (IFNs) are low molecular weight proteins that belong to the class of glycoproteins known as cytokines., they activate immune cells, such as natural killer cells and macrophages to kill the viruses, if this system fails than adaptive immunity starts their response, after about a week the adaptive immunity kicks in, adaptive immune response are highly specific and they have receptors that can identify different type of viruses, but the trade off is that the cells have to be primed to be activated, so it can take few days to be activated

When a virus infects a person (host), it invades the cells of its host in order to survive and replicate.Cells of adaptive immunity relies on B cells and T cells to identify them and destroy them. B cells or T cells have receptors on their surface that allow them to bind to antigen like virus that has a very specific shape, when B cells bind to the surface of the virus it can kill the virus by the process of phagocytosis.

B cells have another important property, they have the capablity to load a piece of antigen (peptide of virus particle) on to special molecule called MHC (major histocompatblity complex) these pieces protein are displayed on the cell surface, T cells have special receptors that can recognize these protein peices of virus which are displayed, The T cell releases cytotoxic factors to kill the infected cell and, therefore, prevent survival of the invading virus. Some B cells can form plasma cells which secrete lot of antibodies which are specific to these viruses and to act on them so it can stop the replication of virus.

Since the individual is not infected with the corona virus, than one of the body's immune system must have been succesfull in preventing the replication of the virus.