SCOTLAND’S national clinical director says the latest data from South Africa has made him more pessimistic about the Omicron variant.

Professor Jason Leitch warned that the early signs indicate the new Covid-19 strain is more transmissible than the Delta variant, which is dominant across the UK.

The variant also appears to be more likely to reinfect people who have had the disease before, though it is too early to say whether it causes more severe illness among patients.

The chief scientist stressed, however, that there was no reason to panic and that the data coming from South Africa was still preliminary.

“We need to know three things: transmissibility, severity of disease and vaccine escape,” he told BBC Good Morning Scotland. “And we don’t know those three things yet.

“Early data from South Africa suggests increased transmissibility. We don’t know yet about severity of disease and unfortunately yesterday [there was] some slightly difficult news about vaccine escape – but very early days and very few people. We need bigger numbers before we can be certain.”

He added: “But I am not overly encouraged about the early data that we’re seeing in South Africa but that’s often what happens – early on it looks bad because it’s just a few people and then as time passes I’m still hopeful that it might not be as bad as the worst case that people are suggesting.

“But yesterday I went a little bit backwards in my optimism.”

Asked to explain why he was feeling more pessimistic, Leitch explained: “The data from South Africa is suggesting increased transmissibility, suggesting reinfection – which is new, again that is smaller numbers, so people shouldn’t panic. But reinfection from natural immunity would suggest this virus can escape to some extent the natural immunity you build up if have the disease.”

The national clinical director continued: “Immunologists suggest the vaccine immunity is better than natural immunity – it’s not quite as simple as that – and that’s why we tell people that have had the disease to still get the vaccine.”

Public health expert professor Devi Sridhar, one of the Scottish Government's pandemic advisers, also gave an update on the latest news about Omicron.

She warned on Twitter that it “looks more transmissible than Delta”, adding: “Likely to become dominant strain. Can re-infect those who had delta recently. Can infect fully vaccinated. Unsure if vaccines protect against severe infection but likely. Priority: vaccinate & slow impact on NHS over winter.”

Leitch also gave his thoughts ahead of the festive season, with questions raised over whether Christmas should go ahead.

He said: “My advice is to not cancel your plans, but give serious thought to how you can make them as safe as possible.”

The professor advised people to get vaccinated and test themselves before any events, pointing out that was the strategy at COP26, where “very few” cases were detected despite thousands of people arriving in Glasgow in the space of a fortnight.

So far, 13 cases of the Omicron variant have been detected in Scotland.

The World Health Organisation says it expects to find out more about the variant in the coming days as scientists publish initial studies.