The variant of Omicron is causing a lot of concern around the world, with it being behind an increase in Covid cases in South Africa. With just 42 cases confirmed in the UK so far, and most European countries seeing numbers in the double rather than triple figures, could this be a sign that the variant may fail to take hold outside southern Africa? It is too soon to say.
There are important differences that make it difficult to compare situations in South Africa and beyond.
Prof Kao, an epidemiologist at the University of Edinburgh and member of the modelling group Spi-M, said that South Africa uses different vaccines from those used in Britain and that different Covid variants are circulating in the country.
The use of the Oxford/AstraZeneca jab has been suspended, as well as the Pfizer/BioNTech jab, because the vaccine is not yet used in the UK. The longer interval between vaccine doses may be an advantage for Britain.
The fact that we had an early vaccine deployment can be helpful in broadening the spectrum of immune response, and this may again mean we have greater protection than South Africa.
Picking up early signs of Omicron's impact is difficult, as Covid is already "running hot" in the UK and some European countries. Covid cases in South Africa were very low before the new variant was detected.
The number of Covid cases in South Africa has gone up from a weekly average of 300 to 1,000 last week and most recently 3,500.
The UK has been experiencing a huge number of cases a day, with figures varying from day to day. If Omicron leads to a rise in cases, it could take longer to become apparent from the data alone.
Case numbers are only one source of information scientists need to hand. One approach experts are using to investigate Omicron's presence in the UK is to look at the results of coronaviruses S-gene tests.
The Alpha variant of the Omicron variant comes up negative on such tests, meaning the test can give a quick indication of whether or not Omicron is present.
Prof Nick Davies of the London School of Hygiene & Tropical Medicine said in a thread that there had been an increase in S-gene target failure in community testing data in England.
The Guardian understands that there may be some prioritisation of cases in areas where Omicron has already been found, but Davies said that around half of the tests in the community are processed by labs that use the test.
Davies found the results only equate to about 60 more samples testing negative for the S-gene than would have been expected, but he said the excess is most likely down to Omicron cases.
It's not clear whether those cases are down to imported infections or linked to transmission within the community. Scientists in England will be watching the data stream carefully over the next several days and weeks to figure out what is happening.
The situation in the UK is in its early days, but there are reasons for concern. The S-gene test results show that the UK is starting to see signs of an exponential rise, and Kao said that there was at least a single large-scale event in Scotland.
Kao thinks it is spreading at a good rate. We don't know if that will be sustained or if it will result in more hospitalisations and deaths.
