Secondary infection with omicron is unlikely. Some studies have shown that it is possible to be infected twice with different subtypes of the omicron variant, but this is rare, so secondary infection with omicron is unlikely. Omicron is a new mutant strain of the new coronavirus. To prevent Omicron daily need to maintain social distance, adhere to often wear masks, maintain hand hygiene and other personal protective measures; to avoid people gathering, bunching, try not to go to crowded, poor air circulation of the place. If fever, cough, diarrhea, fatigue and other symptoms, to wear disposable medical surgical masks and above level masks, timely to the nearest medical institution fever clinic for examination and treatment, the medical process to avoid taking public transportation.