Omicron is a variant of the novel coronavirus B.1.1.529, and the new strains in its spectrum include recombinant variants (e.g., XE, which is a recombinant variant of BA.1 and BA.2), as well as new sub-spectrum strains (e.g., BA.2.12.1, BA.4, and BA.5). The Omicron sub-spectrum BA.2 has about 40 different mutations compared to Omicron BA.1, and is more contagious, while patients previously infected with BA.1 are also at risk of contracting BA.2. The recombinant mutant strains of BA.1 and BA.2 are known as XE. New sub-spectrum strains of omicronjon also include BA.4, BA.5, and others. Some studies have shown that the neocoronavirus omicron variant strains BA.4 and BA.5 have slightly enhanced transmission and immune escape compared to other strains, but it is not clear whether these variants contribute to the severity of the disease in the same way as the other omicron sub-spectrum strains. The existing New Crown vaccine is still effective against the omicron strains, and it is recommended that people who are eligible for vaccination should be actively vaccinated and well protected in their daily lives.