Why do we usually recover from a viral infection after 1 week?

Try to recall the last time you went to the doctor to seek treatment of sore throat, runny nose (with white mucous) and fever, chances are your doctor would say that it is a viral infection, and he/she would issue you medication to relieve the symptom. Your doctor would also mention it might take up to 1-week for a full recovery to happen.

Viral infections are illnesses caused by viruses. Common viral infections include influenza, HFMD, measles, coronavirus (including Covid-19).

Doctors do not randomly give a number and say it is 1-week. To understand more, you will need to understand how our immune system work, especially the adaptive immune system.

The adaptive immune system

When a pathogen penetrates our physical barrier and enters into our system, our innate immune system kicks into action to eliminate the pathogen. For most pathogens that have infected our body before, the white blood cells and antibodies readily seek and destroy the pathogens. However, given how fast pathogens mutate nowadays, it is common for the pathogen to defeat the existing soldiers defending our human body. When this happens, our army sends multiple signals to the control centre at our lymph nodes to build new types of weapons (antibodies) to destroy the enemy.

Our immune system is like a swiss army knife… swift, versatile and deadly.

Most of the time, our adaptive system only kicks in after 5-7 days, when both the physical barrier and the innate immune system both fail to stop the pathogens from infecting our body.

It takes time to find the right formula to defeat the pathogens and during this process, our body continues to heat up to increase the fighting chance. In the event that our immune system fails to defeat the enemy in time before the enemy destroys the essential body functions, death is the consequence.

When faced with an unknown infectious disease, old folks, children and people with chronic illnesses are the most vulnerable to falling ill and dying from it. This is due to the weak immune system in putting up a fight against the pathogen. As such, exercising, balanced diet and sufficient sleep would be essential to staying healthy and helping our body to defeat the ever-dangerous pathogens in our world today.

If you are keen to find out more about the immune system, check out the video below: