As covid-19 approaches its fourth year, "Omicron" continues to mutate and evade the immune system, according to health experts.

"Omicron shows a greater ability to escape the immune system," said epidemiologist and technical officer for the fight against covid-19 at the World Health Organization, Dr. Maria van Kerkhoff, last Wednesday. It is the latest variant of concern in terms of its transmissibility compared to all others,"he said.

The UN organization stressed that the spread of new waves of "Omicron" will depend on several factors such as the immune status of communities, the vaccination rate against covid-19, and the nature of the mutations that occur to the virus.

The mutation changes the genetic code of the covid-19 virus. And some mutations have no effect, while others lead to changes in proteins, which can be beneficial for the virus by making it more transmissible from person to person.

The mutation may be harmful to the virus if the immune system gains an advantage over the pathogen.

The World Health Organization has detected about 540 Omicron mutations, but only 5 are "under surveillance" for changes such as mutations or high prevalence, the Canadian Broadcasting Corporation website reported.

Alarming mutations show one or several features in comparison with the original or ancestral version of the virus:

- It spreads more easily.

- Causes a more severe disease.

- Overcoming current vaccines or treatments.

Doctors and scientists are watching for mutations in the virus protein, which is used to capture and penetrate into our cells.

Genetic sequencing data also indicate that the most elusive variants of immunity are increasing, while the BA strain is decreasing.5 that dominated the summer..

But not everyone who is exposed to the virus gets sick, the main barrier to blocking respiratory pathogens is the nose, which is supported by"mucosal immunity", which asks for help from our immune system when the virus approaches.

When "Omicron" mutants get into the nose and mouth by breathing, they have ways to turn off the natural antiviral immune responses.

As soon as the virus penetrates the first layer of the line of Defense, antibodies act next (antibodies are proteins made by the immune system to help fight infection, and they also serve to secure protection against infection with the same virus in the future).

And antibodies need to "stick" to the virus in order to be effective.

Weeks after a person has been vaccinated, the immune system produces a lot of antibodies that provide protection.

"SARS-CoV-2" the virus that causes covid-19 has other ways to overcome the defenses of antibodies, and is also good at hiding from them.

And since the" Omicron " sub-variants evade the ability of the immune system to fully control it, we are more susceptible to re-infection now compared to previous variants, according to immunologist Dr. Helen dekaloy.