Scientists believe it will take two to three weeks before they can establish whether or not the Omicron Covid variant is more transmissible, causes more severe disease, can make vaccines less effective than Delta – or all three.
This explains why Sajid Javid said on Sunday that the new UK government strategy of tougher travel restrictions and mandatory face masks is to “buy time” while experts work out the nature of the threat.
There is already real world evidence from South Africa and Hong Kong that Omicron is highly infectious – given the sudden rise in cases in the first country, and the fact that a quarantining traveller infected another over a hotel corridor when he opened the door to his room.
What is not yet known is whether it is more infectious than the Delta variant. Omicron has taken off in parts of South Africa because cases of Delta were low, giving it room to compete.
Delta prevalence
In the UK, the situation is different: there are more than 40,000 cases every day, 99 per cent of which are the Delta variant, which itself is very infectious.
This means that a new variant emerging in such a population would have to be even more transmissible to take hold.
Epidemiologists can use data from South Africa and other countries with larger numbers of cases to monitor what are called secondary attack rates – how many people an infected person passes the virus onto.
This information is being collected and analysed right now, but it could be two weeks before the results are published.
What do we know about the Omicron variant so far?
- The variant, first reported on by i, was identified earlier this week, and is called the ‘Omicron Variant’.
- It has an unusually high number of mutations, and scientists believe that some of those mutations are likely to increase transmissibility and vaccine resistance.
- Two cases were identified in the UK on Saturday, in Brentwood and Nottingham. Both cases are thought to be linked to travel from South Africa. A third case was identified in Westminster on Sunday, though the person is no longer in the country.
- The UK has taken the precaution of blocking flights from ten countries where the variant has been identified, including Botswana, Eswatini and South Africa.
- All international arrivals entering England must take a day 2 PCR test and self-isolate until they receive a negative result.
- Face masks will be required in shops and on public transport across England from Tuesday.
- The Prime Minister said he would also seek to speed up the booster jab programme, asking for approval to expand it to under-40s, and lowering the time between jabs.
On the issue of severity, there are reports from South Africa that Omicron is causing only “mild” illness – but these need to be treated with caution, because it is still early days.
Dr Angelique Coetzee, a doctor in Pretoria who was the first to spot unusual symptoms in a covid patient on 18 November, said she had only seen mild illness so far.
The different symptoms – which she has now observed in a number of cases – are extreme tiredness, body aches and pains, but no cough or loss of smell associated with traditional Covid and she has not admitted anyone to hospital.
Young population
This could give hope that it is a much milder illness, but there are two caveats: firstly, most of these cases are in the 20- to 40-year-old age group, who are traditionally the first in a population to contract a new virus in an outbreak as they are the most mobile.
Severe illness would not be expected in this age group anyway. Secondly, it can take two to three weeks for Covid symptoms to develop into a severe enough case that hospital admission is needed.
As Dr Coetzee herself said on BBC1’s Andrew Marr programme: “Two weeks from now on I may well say something different.”
Vaccine effectiveness
Finally, on the issue of vaccine effectiveness, the time needed for scientists to confirm how Omicron behaves against the jabs will also take around two to three weeks.
This is because they need to analyse both lab-based and real world data to assess how well the vaccines work.
Under secure conditions in the lab, scientists are growing a live version of the variant to test it against different covid vaccines, and this process will take about two weeks.
In the real world, experts will compare the vaccination status of people in hospital with Omicron, and with the severity of illness from Omicron for people fully vaccinated with that suffered by people who had Delta who had also received both jabs.
This process will also likely take two to three weeks, because there are not enough people in hospital suffering from Omicron to produce meaningful, statistically significant results.
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