The WHO, in its latest guidance to authorities and travellers, says people over 60 years of age and those with underlying health conditions should be advised to postpone travel as they are at higher risk of disease and death.
This was in line with its advice regarding over 60s since December 2020, regardless of a traveller's vaccination status, and did not represent any change in guidance, a WHO spokesperson said.
First reported in southern Africa a week ago, the variant has brought global alarm, led to travel bans, and highlighted the disparity between massive vaccination pushes in rich nations and sparse inoculation in the developing world.
National authorities in countries of departure, transit and arrival may apply a multi-layered approach to mitigate risk so as to delay or reduce importation or exportation of the Omicron variant, the WHO said on Tuesday.
"Measures may include screening of passengers prior to travel and/or upon arrival, and use of SARS-COV-2 testing or quarantine of international travellers after thorough risk assessment," it said.
All measures should be commensurate with the risk, time-limited and applied with respect to travellers' rights, it said.
"Blanket travel bans will not prevent the international spread, and they place a heavy burden on lives and livelihoods," it said.
Some 56 countries were reportedly implementing travel measures aimed at potentially delaying import of Omicron as of November 28, it said.
