What is the Delta variant? Why Covid variants have been named after letters in Greek alphabet - and list of names

Covid variants will now be named after letters of the Greek alphabet to avoid “stigma”, the World Health Organisation has announced.

Instead of being named after the place they were discovered, experts working with the WHO have developed the new labels for variants of the virus.

Four variants of concern, including the Kent variant and the variant first discovered in India have been renamed.

So, what is each variant’s new Greek name?

Here is everything you need to know.

What is the Delta variant?

The B.1.617.2 variant, often known as the Indian variant, has been labelled Delta.

The variant of concern is now the dominant strain in the UK, Public Health England confirmed on Thursday (3 June).

Scientists believe the strain has overtaken the variant first discovered in Kent to become the most common in the country.

Experts also say there could be a greater risk of hospitalisation linked to the Delta variant, based on early evidence.

The number of cases of the strain confirmed by lab analysis rose by nearly 80% over the last week to 12,431.

"With this variant now dominant across the UK, it remains vital that we all continue to exercise as much caution as possible," said Dr Jenny Harries, chief executive of the UK Health Security Agency.

"The way to tackle variants is to tackle the transmission of Covid-19 as a whole."

What have the other variants been named?

Meanwhile, the variant first found in Kent – B.1.1.7 – will now be given the letter Alpha, while B.1.351, often referred to as the South African variant, has been named Beta.

And the P.1 Brazilian variant has been labelled Gamma.

These are the new names for each of the variants:

- Kent or B.1.1.7 - Alpha

- South Africa or B.1.351 - Beta

- Brazil or P.1 - Gamma

- India or B.1.617.2 - Delta

- US or B.1.427 / B.1.429 - Epsilon

- Brazil or P.2 - Zeta

- B.1.525 - Eta

- Philippines or P.3 - Theta

- US or B.1.526 - Iota

- India or B.1.617.1 - Kappa

The WHO said these labels were chosen after wide consultation and a review of many naming systems.

The organisation said the labels do not replace existing scientific names, which convey important scientific information and will continue to be used in research.

Why have the strains been renamed?

Critics had warned that the variants’ previous names could stigmatise the countries where they were first discovered.

And some said the rise in coverage of the variant first found in India as it spreads could encourage racism against Indian people.

Last year saw an increase in hate crimes against Asian people due to the fact the pandemic originated in China, according to the advocacy group End the Virus of Racism.

And former US president Donald Trump was heavily condemned for consistently calling coronavirus the “China virus”.

“While they have their advantages, these scientific names can be difficult to say and recall, and are prone to misreporting,” the WHO said.

“As a result, people often resort to calling variants by the places where they are detected, which is stigmatising and discriminatory.

“To avoid this and to simplify public communications, WHO encourages national authorities, media outlets and others to adopt these new labels.”