The newest mutated strain of the new coronavirus is now called Omicron, and subtypes BA.1, BA.2, BA.4, and BA.5 have emerged from the Omicron strain. Originally named BA.1, omikron has mutated and evolved into BA.2, which has an increased transmission rate compared to BA.1. BA.4 and BA.5 have been found in South Africa, and are more infectious than the other mutated strains and have become the main prevalent strains, and BA.4 and BA.5 may escape from early infections and vaccine-generated antibodies. Booster shot 3 is an effective preventive method against the omicron strain. Although BA.4 and BA.5 may escape from the antibodies produced by the vaccine, vaccination with shot 3 is still an effective way to reduce the mortality of the new strain. Prevention and control of the new coronavirus variant remain the same: wear masks, gather less, and disinfect diligently. Patients infected with the new coronavirus should be isolated promptly and treated as prescribed by a physician.