As we know, [COVID-19](https://ul.orna.me/KOge/librarydisease?id=221) is especially dangerous for immunodeficient people. The emergence of the new strain in South Africa is not surprising, as the country has a low vaccination rate. ## How strains emerge COVID-19 is a chain of genetic material in the form of RNA with a coat of proteins. It enters the body, penetrates the cell, and begins to multiply. If the human immune system fails to recognize and destroy the virus, it creates many copies. If the immune system fights back, the RNA of the virus can begin to modify itself to fool the immune system and freely multiply further. This is especially common in people with an altered or inadequate immune system. These mutations persist and become part of the virus genome, which causes new strains, or variants, to emerge. The process of virus evolution is the way the virus survives. COVID-19 already has many variants, which are named by the World Health Organization (WHO) according to the Greek alphabet: - the alpha strain was discovered in September 2020 in the U.K. and then became the dominant strain in the U.S. and several other countries. - the beta strain appeared in December 2020 in South Africa and spread to many countries. - the gamma strain was detected in January 2021 in Brazil, then spread to more than 70 countries. - The delta strain emerged in October 2020 in India. It is now the most common, insidious, and contagious variant of the virus, and can cause a severe course of the disease, especially in the unvaccinated. There are also other variants of the virus that are not very common. Scientists across the world are monitoring the virus genome, deciphering it, and tracking its movements. ## What to expect from Omicron According to scientists, Omicron has many mutations in its S-protein. So far, this is the primary difference between Omicron and other variants—which makes it potentially dangerous, contagious, and capable of bypassing vaccine immunity since most vaccines induce immunity to the S-protein. However, no one is ready to draw conclusions about the scale of the threat since Omicron is fairly new. It is suspected that Omicron has become more contagious and volatile than its predecessor delta. This belief partially stems from a case in Hong Kong where the infection was transmitted between two men who were quarantined living in adjoining rooms and wearing respirators with exhalation valves. Additionally, both patients had been vaccinated with the Pfizer vaccine. The WHO has made a statement that there is an increased risk of Omicron infection after experiencing COVID-19. It appears that people who have had COVID-19 can more easily become infected with the new strain. Researchers around the world are currently exploring Omicron and what kind of vaccine modifications or new vaccines might be required to fight it.