Covid-19: Immune response

Corona virus disease (COVID19) is viral disease caused by recently discovered corona virus. Corona viruses (COV) are family of viruses causing diseases such as Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS), and COVID-19 ranging from common cold to severe illnesses. Corona viruses are named after crown-like spikes, which are RNA viruses on their surface. Corona Virus Disease (COVID 19) is initiated by Corona Virus 2 Severe Acute Respiratory Syndrome (SARS-COV-2). So we will have a brief summary of immune system regarding its defense of the human body from COVID-19, explaining the immune system's process, how it functions, and its virus-fighting mechanism. The immune system faces a dynamic overtime adaptation, resulting in functional and phenotyping improvements, which may clarify at least age distribution in COVID-19 lethality by remodeling the immune response observed among the elderly.