The Covid-19 virus consists of a strand of RNA covered by a fatty outer layer, which in turn is covered in spikes, like a sea urchin. Its only purpose is to reproduce, and it has found humans to be such warm and welcoming hosts.

When your cells are infected by a normal virus, they send out distress signals, warning the body that it is being attacked. Your immune system then seeks out and destroys the invader. Unfortunately, the Covid-19 virus has found a way to get around this. It produces a protein that can block these early alarm signals. The result is that people can be contagious without showing signs of infection. So, a person can wander around, excreting viral particles, unaware of the threat they pose to others.

Eventually the body will start producing the antibodies to attack the invaders. How quickly this happens, and how a person’s body reacts, plays a big part in determining whether they have a mild illness or will end up very ill.

Thanks to scientists in Australia who have identified how the body’s immune system fights the Covid-19 virus, we have a clearer idea of the timeline and what happens to someone suffering a relatively mild Covid-19 infection.

The asymptomatic stage can start 5 days before a person starts presenting with symptoms. The IgM antibody becomes detectable from day 7 and appears to disappear after 21 days. While IgG antibody can begin only at day 14.