VIRUS EVOLUTION

TOPIC: Science & Tech

Context- Variants do not always evolve to become less virulent: WHO

With the omicron variant disease severity has been far less compared to Delta. However virus don’t inevitably evolve towards being less virulent and it is not true that virants are becoming milder.

Concept-

What does it mean to say a virus mutates or changes?

When a virus replicates or makes copies of itself, it sometimes changes a little bit.
These changes are called “mutations.”
A virus with one or several new mutations is referred to as a “variant” of the original virus.
The more viruses circulate, the more they may change.
These changes can occasionally result in a virus variant that is better adapted to its environment compared to the original virus.
This process of changing and selection of successful variants is called “virus evolution.”
Some mutations can lead to changes in a virus’s characteristics, such as altered transmission (for example, it may spread more easily) or severity (for example, it may cause more severe disease).
Some viruses change quickly and others more slowly. SARS-CoV-2, the virus which causes COVID-19, tends to change more slowly than others such as HIV or influenza viruses.
SARS-CoV-2 spreads primarily through human-to-human transmission, but there is evidence of transmission between humans and animals. Several animals like mink, dogs, domestic cats, lions, tigers and raccoon dogs have tested positive for SARS-CoV-2 after contact with infected humans.