Financial markets fell sharply after the head of drugmaker Moderna said existing COVID-19 vaccines would be less effective against the Omicron variant. The World Health Organization warned countries on Tuesday not to impose blanket travel bans over the new Omicron coronavirus variant as governments and scientists try to determine how much protection current vaccines would offer against the strain.
Financial markets fell sharply after the head of drugmaker Moderna said existing COVID-19 vaccines would be less effective against the Omicron variant. MSCI's gauge of stocks across the globe shed 1.39% a day after broad declines in Europe and Asia.
BioNTech's chief executive struck a cautiously positive note, saying the vaccine it makes in a partnership with Pfizer would likely offer strong protection against severe disease from Omicron, which was first reported in southern Africa a week ago.
The questions over vaccine effectiveness came as cases of the new variant spread, with the first reported case in Latin America emerging in Brazil. The country's health regulator, Anvisa, said a traveller arriving in Sao Paulo from South Africa and his wife were both apparently infected.
Canada will extend its ban on travellers from southern Africa to also cover those from Nigeria, Malawi and Egypt, health officials said on Tuesday, for a total of 10 countries.
Canada will require people arriving by air from all nations except the United States to take a COVID-19 test, Health Minister Jean-Yves Duclos said.
The World Health Organization (WHO) asked countries to apply "an evidence-informed and risk-based approach" with any travel measures, including possible screening or quarantine of international passengers. Blanket travel bans would not stop the spread of Omicron, it said.
However, the WHO said people over age 60 who are not fully vaccinated or do not have proof of previous SARS-COV-2 infection and those with underlying health conditions should be advised to postpone travel. The WHO amended its earlier statement to make clear that the warning for those over 60 is for people who are not fully vaccinated.
WHO Director-General Tedros Adhanom Ghebreyesus said he understood the concerns about Omicron. But he added "I am equally concerned that several member states are introducing blunt, blanket measures that are not evidence-based or effective on their own, and which will only worsen inequities."
Vaccine questions