Experts say important information about strain Omicron will be available in the next few days

"We're still in the early days of learning about this variant," said Maria van Kerkhove. It's possible that we don't have all the information on transmission yet. There are some hints, but I'll say it's still there. We are still learning. We expect to have more information about the transmission of the Omicron variant within the next few days, not weeks."

As such, WHO has shortened the time to evaluate data on the Omicron variant. When it was identified as a "variant of concern" last week, WHO forecast it would take several weeks for the work.

Two important questions to answer now are whether Omicron is more transmissible, and whether it can overcome the vaccine.

Vaccine manufacturers say it will take about two weeks to assess the effectiveness of vaccination against the Omicron variant.

One possibility, Van Kerkhove said, is that Omicron could spread faster than the current Delta dominant strain. However, she said it is unclear whether Omicron will increase the number of severe cases.

Soumya Swaminathan, WHO Chief Scientific Officer: "We know that people over 45 years of age, with underlying medical conditions, are at greatest risk of severe illness after being infected with the virus, whether it's an Omicron strain or a Delta strain or another variant. . We still need to find out if the vaccine has reduced protection, but we believe the vaccine will still protect against severe disease as with other variant strains."

Meanwhile, Kate Bingham, former head of the UK's Covid-19 vaccine task force, said scientists will know the effectiveness of the vaccine against the Omicron variant within a week. Ms Bingham said Britain now has the capacity to rapidly test existing vaccines against new variants.

"It's not something you can do overnight, but we'll get the data, I think within a week we'll be able to see if the vaccine is effective," Ms Bingham said.