Changes at a very micro level have resulted in the hugely transmissible Omicron variant of the SARS-CoV-2 virus that is spreading the Covid-19 infection at an alarming rate. The multiple mutations in the virus have opened our eyes to how variants differ in their impact on our health, making it imperative to keep them under close watch.
An enzyme called Angiotensin-converting enzyme-2 (ACE-2) on the surface of human cells plays a crucial role in preventing the harmful activities of a protein named angiotensin-2 (ANG-2). If allowed to have its way, ANG-2 is known to cause inflammation, increase blood pressure, damage the linings of blood vessels and injure tissues. ACE-2 inhibits these activities by breaking ANG-2 into counteracting molecules, thus eliminating the harmful effects. But ACE-2 is also a receptor for this virus, helping the latter bind with it.
In doing so, it prevents ACE-2 from performing its normal function of regulating the harmful ANG-2 signalling. The vaccines that have emerged through the first two waves of the pandemic are known to generate antibodies that can recognise SARS-CoV-2 and stop it from attaching to ACE-2, by themselves binding with the spike protein of the virus. However, recent discoveries by a team of researchers from University of Missouri-Columbia shows the latest variant has emerged due to 46 specific mutations, many occurring in the spike protein itself. These mutations ‘fool’ the antibodies from recognising the virus and binding with its spike proteins. That explains why a huge section of the population continues to get infected by Covid-19 despite completing double vaccination.
However, for reasons yet to be understood, Omicron mostly restricts itself to the nasal and throat regions without affecting the lungs. But that should not make us complacent about subsequent variants, the mutations of which could render them more dangerous, like the earlier Delta variant. This calls for a tight vigil on how and when the virus mutates and to be ready with appropriate treatment modules to meet the challenge.