Since its emergence in late 2019, the new Corona virus has seen a number of different mutants, but Delta and Omicron have received the lion's share of scientific and media attention.

The Omicron mutant has sparked considerable outcry over the past days, following its first registration in South Africa and its spread to various continents of the world, causing a number of States to reimpose restrictions and precautions.

The World Health Organization (WHO) said that the new corona mutant "Omicron" is likely to spread globally, posing a "very high" global risk.

Before it in the middle of this year, the Delta mutant left a record number of casualties around the globe, killing thousands.

So what's the difference between Omicron and Delta?

The scientific journal Previnchen said the delta mutant is more infectious than the previous Cofid-19 mutants, and may cause more serious symptoms.

In contrast, omicron contains a large number of mutations, according to the World Health Organization. It is difficult to determine once and for all how serious or weak it is, but early indications suggest that most cases of this mutant are mild and there are no serious cases.

Is omicron worse than delta?

Thomas Russo, professor and head of the Department of Infectious Diseases at the University of Buffalo in New York, says: "The short answer is we don't know."

He added: It's true that Omicron contains a large number of mutations, which are based in the Spike protein region, but are these mutations preparing the situation to go in the bad direction or are they going to cancel each other out? We don't know yet. "

In general, the symptoms of COVID- 19 have remained fairly constant, regardless of mutations, including fever, cough, shortness of breath, fatigue, muscle pain, sore throat, loss of taste and smell.

The data for Omicron is still very preliminary, but a doctor who treated Omicron's patients said, in a press release, that people suffered "very mild symptoms," such as body pain with a little headache and a throat itch, according to Previnchen.

He added: "There's no cough or loss of sense of taste and smell."

As for Delta, this mutant is known to spread more rapidly and lead to serious injuries in people who have not received the vaccine.

The symptoms are cough, fever or headache, as well as significant loss of smell and taste.