Booster jabs will be offered to all adults in the UK and the gap between second doses and boosters will be reduced from six months to three in an attempt to stave off a feared new wave of the Omicron virus. Another 11 cases have been detected in the UK.

Children aged 12 to 15 will be invited for a second dose three months after their first. 

We’ve entered a “period of scientific uncertainty”, Prof Jonathan Van-Tam, England’s Deputy Chief Medical Officer, admitted this afternoon. But “while we wait for the mist to clear,” it has “never been more vital” that individuals come forward for their boosters.

In addition to the ramped up booster programme, all close contacts of suspected Omicron cases will be advised to self-isolate for 10 days, regardless of their vaccination status.

From Tuesday, face coverings will once again be compulsory in shops and on public transport in England and ten countries in southern Africa will be added to the UK’s travel “red list”. 

What do we know so far about the Omicron variant? 

First detected in South Africa last week, it has since been identified in countries across the world, including Australia, Germany, Israel and Hong Kong.

The World Health Organisation, which has now designated it a “variant of concern,” says preliminary evidence suggests “it poses an increased risk of reinfection.”

It is heavily mutated, with 32 mutations on the spike protein alone – twice as many as the Delta strain – and worrying since our current vaccines target the spike protein. “It is likely there will be an impact on the effectiveness of vaccines,” Prof Van-Tam has warned – with some scientists estimating it could render vaccines 40 per cent less effective.

However, crucially, there is still no solid evidence that these mutations give the Omicron strain a transmission advantage over the Delta, or that if will cause more severe disease. 

Scientists say it could be at least two weeks until we have more definitive information on transmissibility- and four to six until we know more about Omicron’s impact on hospitalisations and deaths.

In South Africa, where Omicron cases are still concentrated, medics say the strain is causing mild symptoms so far— such as a headache and tiredness —and hasn’t yet led to a single hospitalisation or death. While daily infections soared to over 6000 on Saturday – a 20-fold increase on the 306 positive tests registered two weeks earlier – deaths have remained flat, with 20 recorded that day. 

We can’t draw firm conclusions from this anecdotal evidence- not least because cases have so far been detected in low-risk younger people, plus there is a delay in people catching the virus and becoming severely unwell. 

But the UK government isn’t taking any chances. 

The booster roll-out will still be prioritised in order of vulnerability, and the UK is not the first country to extend the booster roll-out to youngsters. In Israel, those aged over 12 have been eligible for a booster since August. Yet today’s announcement – which will make tens of millions of Brits eligible at the drop of a hat – does raise questions about capacity, and whether there are enough GPs and staff to administer all these extra jabs? According to Prof Van-Tam, the NHS will announce in the coming days how it will “operationalise” the new directive on boosters. 

Another concern is that the rule requiring any close contacts of Omicron cases to self-isolate will unleash fresh chaos in schools – just when we thought the disturbance to children’s education was lessening. 

There is also the challenge of identifying which virus strain individuals are indeed infected with. Lateral flow tests cannot tell you whether you have the Omicron variant, as only PCR tests can be processed for DNA sequencing. What’s more, just between a third and a half of the UK labs where PCR tests are sent actually have the required technology to detect which strain. 

There’s still a chance that these new measures will transpire to be unnecessary – in fact, this new variant could turn out to be even less deadly than the delta. Professor Karl Lauterbach, a clinical epidemiologist who is in the running to be Germany’s next health minister, says it’s possible that the Omicron strain’s vast array of mutations has altered the virus so that it’s optimised to infect but is less lethal. This follows a pattern of how respiratory viruses have evolved in the past and it would accelerate the coronavirus transition from pandemic to endemic. 

Far from putting Christmas plans in further jeopardy, if Prof Lauterbach’s suspicion is confirmed, then this currently concerning development could turn out to be a “Christmas gift”.