COVID-19 vaccines are effective against Omicron, the latest coronavirus variant, and can reduce severity of illness and mortality rate, Xu Wenbo, director of National Institute for Viral Disease Control and Prevention (IVDC) under Chinese Center for Disease Control and Prevention, told China Media Group on Monday.

The variant has a large number of mutations, but it doesn't necessarily mean that it is more transmissible or has greater degree of immune escape than Delta, said Xu.

"In general, Omicron remains the novel coronavirus, which is not going to change in a disruptive way," he said.

The variant cannot completely break through the immune barrier because in addition to antibody and T-cell immunity, people are also protected by different types of vaccines, though the protective effect of vaccines need to be further studied, the expert said.

Scientists are attempting to figure out whether Omicron's mutations would lead to greater transmissibility than the Delta variant, how strong the variant's ability is to escape immunity and how the variant comes about, said Xu.

He advised the public to stick to preventive measures, including wearing masks, practicing social distancing, monitoring health and reducing non-essential traveling overseas, especially to countries or regions where the variant has been detected or is suspected to be circulating. 

The World Health Organization has listed Omicron as a "variant of concern," and said the overall global risk related to it is assessed as "very high."

At least 17 countries and regions have detected the variant. Countries worldwide are taking containment measures while at least 70 countries and regions have imposed travel bans from some African countries, according to a CNN tally.

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