Covid spread: R number falls to 0.8-1.1

If the virus was in retreat, it would be the first time in three months

Vaccinated people infected with the Delta variant may spread it as easily as those not immunised, research by Public Health England suggests (AFP via Getty Images)

Covid-19 could be on the retreat in England, after the crucial reproduction rate of the virus fell below 1 for the first time since May, figures suggest.

Public Health England says the estimated R value range is 0.8 to 1.1, down from the previous 1.1 to 1.4.

The fall came as the government’s senior scientific and medical advisers agreed a new alert system for coronavirus, to reflect increasing levels of vaccination within the population.

In recognition of the weakened link between infections and serious illness or death, the new levels mean higher numbers of positive cases are required for the UK to move up to a higher alert status – effectively reducing the likelihood of harsh lockdown restrictions.

Britain moved in May from alert level 4 (epidemic in general circulation, transmission high or rising exponentially) to level 3 (epidemic in general circulation) and this remains unchanged.

But in future, a move to level 4 will also require the Joint Biosecurity Centre (JBC) to assess that the pressure on the NHS is widespread and substantial or rising. The weekly case rate will have to be 250 per 100,000 people, rather than the previous 50, and numbers of new infections will have to be 30,000 rather than 10,000 a day.

And the UK could de-escalate to level 2 – signifying that the pandemic is present but cases and transmission is low – on the grounds of a weekly case rate below 25 per 100,000, rather than the previous ten, and new infections, hospital admissions and deaths are on a downward or stable trend for four weeks.

The new system was agreed by the JBC with the chief medical officers of the four nations and the national medical director for England to bring it in line with the evolving nature of the Covid-19 pandemic.

The Department for Health and Social Care said: “The current methodology is being updated to take into account the weakening, but persistent, link between Covid-19 cases and severe disease, hospitalisations and deaths, as well as the risk posed by variants of concern and variants under investigation.”

Changes in the alert level do not automatically trigger amendments to the level of lockdown restrictions on social and economic life but are taken into account by ministers when making judgements on possible curbs.

Today’s R figure means that for every ten people infected, they will infect between eight and 11 others, on average.

At the lower end of this range, cases would no longer be growing exponentially and the disease would be dwindling away after hitting a peak in the middle of last month.

It comes after holiday bookings shot up by 193 per cent on Thursday, following another easing of the UK’s travel rules.

The estimated daily growth rate range of the coronavirus in England was -3 per cent to +1 per cent, compared with estimated growth of between +2 per cent to +5 per cent each day last week.

However, research from Public Health England suggests that vaccinated people infected with the Delta variant of coronavirus may be able to spread it as easily as those who have yet to be immunised.

Although the jab appears to reduce an individual’s overall risk of catching Delta in the first place, once someone is infected there appears to be limited difference in the viral load between the vaccinated and unvaccinated, the experts suspect.

The prevalence of Covid infections is thought to have fallen in England last week but risen in Northern Ireland.