UK becomes 1st country to approve Omicron vaccine

The United Kingdom (UK) has become the first country to authorise a Covid-19 vaccine tailored to the Omicron variant.

The UK medicines regulator (MHRA) gave the so-called bivalent vaccine made by U.S. drug company Moderna conditional approval as a booster for adults.
The MHRA gave its approval for the vaccine based on the clinical trial data that indicated a triggered 'strong immune response' by the vaccine against the Omicron variant (BA.1) as well as the original Covid-19 virus.
The exploratory analysis of the clinical trials reveals that the shot was also effective in generating an immune response against the currently prevalent Omicron offshoots BA.4 and BA.5.

Variants of Interest

A variant with specific genetic markers that have been associated with changes to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination, reduced efficacy of treatments, potential diagnostic impact, or predicted increase in transmissibility or disease severity.
There are currently two:
- Mu (B.1.621), which emerged in Colombia in early 2021
- Lambda (C.37), which emerged in Peru in late 2020

Mutation, Variant and Strain

When a virus replicates it doesn’t always manage to produce an exact copy of itself.
This means that, over time, the virus may start to differ slightly in terms of its genetic sequence.

Any changes to the viral genetic sequence during this process are known as a Mutation.
Viruses with new mutations are sometimes called Variants. Variants can differ by one or multiple mutations.
When a new variant has different functional properties to the original virus and becomes established in a population, it is sometimes referred to as a New Strain of the virus.
- All strains are variants, but not all variants are strains.