Later today, the ONS coronavirus survey will confirm that Covid-19 is on the march again everywhere, not just in regional pockets - though there are regional variations. And it will also show that infection is rising in all age groups, though the incidence of the illness is highest by a margin among those aged 17 to 29.Which is why, as I reported on News at Ten on Tuesday, the government is looking at introducing additional social-distancing measures on a national basis - such as forcing pubs, clubs and restaurants to turf out customers at 10pm, or reverting to closing them altogether, for a couple of weeks or so.
And the strong hope of Boris Johnson and the health secretary, Matt Hancock, is that implementing this kind of circuit breaker will allow the non-social parts of life (going to work, school and university) to continue in their current abnormally reconfigured way.
To be clear, virus and epidemic experts are divided about these measures. Some think they are overkill. Some fear they will be too little too late. I have observed this split in opinion even among scientists who advise the government.
The most important difference is over the magnitude of the probability that we are staring at a second wave as significant or worse than what we suffered in March, April and May.
One leading epidemiologist told me he is confident that - even without further preventative measures nationally, and simply addressing outbreaks as they flare up locally or regionally - we are looking at a series of relatively small localised waves of infection, which will not overwhelm hospitals. By contrast, another told me he fears we may already be too late to stem a potentially devastating second wave. And with scientists divided, it all becomes about politics.
The relevant political background is that Boris Johnson, his health secretary and the rest of his government are widely seen to have moved too late to prevent the first wave. Having eventually applied the sledgehammer of total lockdown at huge economic cost, this time they will employ the precautionary principle. But as one scientist said to me, it is rum that a supposedly libertarian Tory government does not trust people to do the right thing, but feels obliged to compel us. That said, the priority of the Chief Medical Officer, Chris Whitty, is to suppress the incidence of the virus to a level that doesn't prevent the NHS from treating other diseases and conditions.And although the economic cost of new constraints on the hospitality industry is significant, they would be a fraction of the blow to our prosperity of a full-scale new lockdown.
The other hugely important question is whether the virus can be kept at a low enough level to prevent a return to strict quarantine, or shielding, for the most frail people.
The isolation of shielding brings a terrible emotional and psychological price for the shielded. But those close to the government tell me they fear there will be a need to re-introduce shielding soon.
PS. One reassuring finding in the ONS’s Covid-19 survey, which has now been published, is that as yet there is only the slenderest of evidence of infections rising among the most vulnerable age group, those over 70 - which shows that there has been important behavioural change.
The worry of Chief Medical Officer Whitty is that without further national measures to compel additional social distancing there will be contagion from infected young people to the at-risk older generation, and what we are seeing is simply a lag in a rise in infections up the age scale.