Context: Last few weeks have witnessed hand sanitisers going off the shelves, to the extent that there is now a government order to ensure availability and to prevent profiteering. 

Reason for demands peaking suddenly:

  • Handwashing with soap (for 20 seconds) and sanitisers has emerged the greatest weapon against COVID-19 pandemic, as it kills the virus. 
  • The sanitiser used should ideally have an alcohol content of 60% or more. Alcohol’s function in killing the virus is much the same as that of the common soap.

Structure of the virus:

For understanding how soaps and sanitisers help in killing the virus it is necessary to understand the structure of the virus. 

  • According to the US National Institutes of Health, like other coronaviruses, SARS-CoV-2 particles are spherical and have proteins called spikes protruding from their surface. 
  • These spikes latch onto human cells, then undergo a structural change that allows the viral membrane to fuse with the cell membrane. 
  • The viral genes can then enter the host cell to be copied, producing more viruses. 
  • SARS-CoV-2 spikes bind to receptors on the human cell surface called angiotensin-converting enzyme 2 (ACE2).
  • All of this is held together by a fatty layer, called an envelope. 

How hand sanitisers protect against the novel coronavirus? 

  • The novel coronavirus has a lipid envelope, soap (being a detergent) and sanitisers(having at least 60% alcohol) destroys the envelope and kills the bacteria. 
  • Even when the virus comes out through droplets when an infected person coughs, it is still within a cell. 
  • Replicates only inside the cell: Even if it is not within the cell, it can stay alive in surfaces for some time. It replicates only when within the cell. That is how soap or alcohol attacks the virus.
  • Disruption of the envelope causes the virus to come undone, and kills it. That is why experts and public health institutes across the world agree that handwashing for at least 20 second is the most fail safe prevention of COVID-19.