GENEVA — The World Health Organization is announcing a new nomenclature for the COVID-19 variants that were previously — and somewhat uncomfortably — known either by their technical letter-number codes or by the countries in which they first appeared.

Hoping to strike a fair and more comprehensible balance, WHO said it will now refer to the most worrisome variants — known as “variants of concern” — by letters in the Greek alphabet.

So the first such variant of concern, which first appeared in Britain and can be also known as B.1.1.7, will be known as the “alpha” variant. The second, which turned up in South Africa and has been referred to as B.1.351, will be known as the “beta” variant.

A third that first appeared in Brazil will be called the “gamma” variant and a fourth that first turned up in India the “delta” variant. Future variants that rise to “of concern” status will be labeled with subsequent letters in the Greek alphabet.

WHO said a group of experts came up with the new system, which will not replace scientific naming systems but will offer “simple, easy to say and remember labels” for variants.