SARS-CoV-2 Omicron variant: characteristics and prevention
Mar 21, 2022
Peking University, March 21, 2022: Recently the epidemic control requirements are upgrading. Professor Liu Ming from School of Public Health will tell us more about how to protect ourselves and stay safe in the battle against the virus.
Omicron has the characteristics of rapid spread and immune escape, and has quickly become a predominant strain in the world
Transmission characteristics of Omicron variant strains
· Omicron is about 30% more contagious than Delta; roughly similar to or more contagious than the Delta variant
· The basic regeneration base number (R0) of the Omicron variant is higher than 2, while the R0 value of the Delta variant is much lower than 1
· Omicron had a hazard ratio of 2.39 for reinfection to primary infection, three times that of the Beta and Delta variants
· Omicron will have "immune escape", allowing our previous immunity to escape by Omicron, resulting in re-infection.
The protective effect of vaccines on Omicron mutants
· Vaccination booster and sequential booster immunization are aimed at effectively improving immunity to Omicron variant, especially in preventing severe illness.
· The booster shot of the vaccine can increase the antibody protection against the Omicron variant by 25 times, and the antiviral ability after the booster shot is equivalent to the 95% protection provided by the two vaccines against the original virus strain.
· Sequential booster immunization: If the booster is used in a sequential way, instead of the basic vaccine type that has been used before, the efficiency is high. Basic immunity is not enough to protect the homologous-booster-users from Omicron infection, homologous booster can only prevent severe illness and death. Currently, Boosting the vaccine is a top priority.
Suggestions for China‘s prevention and control strategies
· Speed up the whole process of vaccination
· Accelerate vaccine research against new mutant strains
· Strengthen overseas import risk management and control
· Adhere to normalized epidemic prevention and control measures: wear masks, reduce gatherings, wash hands frequently, keep on monitoring
In the context of epidemic prevention and control, everyone needs to abide by the rules and do things in accordance with the prevention and control requirements, so that the epidemic can be controlled well and we can be protected from infection.
Source: ISD PKU
