Can Our Immune System Protect Us from COVID-19?
Representative image / Reuters.
COVID-19 has been expanding its footprints across the world. Only a few countries have managed to control the deadly virus. The SARS-CoV-2 has infected more than four crore people globally and claimed the lives of over 12 lakh people. In India, more than 80 lakh people have contacted the COVID-19 and over one lakh have died due to SARS-CoV-2.
How SARS-CoV-2 attacks human body?
The deadly virus enters the body through the eyes, mouth or nose. Breathing process facilitates the transfer of the virus to the lower respiratory tract. In the tract, spike proteins of the novel coronavirus, acting like a key, lock into epithelial cells. The virus remains undetected for some time and during this time, they hijack cell’s machinery, replicate, multiply and infect adjoining cells.
Every human has innate immunity, which is a defence against pathogens. It gives the body’s adaptive immune system to generate antibodies against viruses. But sometimes, immune system overreacts, endangering a person fighting off an infection.
What happens is that chemokines, some of the proteins that initiate inflammation, alert other immune cells to gather where the infection exists. Meanwhile, some cytokines guide neutrophils, a type of immune cell, from the blood vessels to the infected tissue. They (cytokines) can cause increase of heartbeat, body temperature and also trigger blood clots to trap the pathogen. Besides, the cytokines stimulate the neurons in the brain to modulate body temperature and other physiological responses that occur during killing of the virus.
However, when the body is unable to control the production of the cytokines, it gives rise to a situation called “cytokine storm,” reported The Print. The over production of cytokines could in some cases lead to organ failure. The cytokine storm has devastating consequences for the people infected with COVID-19.
A new study has surfaced which reveals that antibodies decline rapidly after a person catches the infection. According to BBC, researchers at the Imperial College London observed the number of people testing positive for antibodies has dwindled by 26 per cent between June and September.
"Immunity is waning quite rapidly, we're only three months after our first [round of tests] and we're already showing a 26 per cent decline in antibodies," BBC quoted Prof Helen Ward, one of the researchers, as saying.