The World Health Organization has called for a balanced global response to the Omicron coronavirus variant, saying countries which report cases of the new strain should not be penalised, as the South African scientists behind its discovery prepare to ship samples to labs worldwide.

The discovery of a new, highly mutated coronavirus variant in Botswana earlier this month has alarmed global health officials, as it appears to be behind a surge in cases in South Africa. The so-called Omicron variant displays preliminary characteristics that suggest it is able to reinfect patients and evade vaccines. It is not yet known whether it worsens symptoms.

A number of countries have imposed severe travel restrictions on the southern African region. Switzerland has also restricted travel from Israel, Hong Kong and Belgium, where two cases of the variant have been confirmed.