The Daily Telegraph
‘Plan B’ may not be needed, despite experts’ concerns
After the Government announced that “Plan B” is now on the cards, attention has turned to what might trigger the nuclear option of further restrictions.
Looking at the advice given to ministers last week from scientists gives some hint of what to expect.
The Scientific Pandemic Influenza Group on Modelling, Operational sub-group (SPI-M-O) issued a consensus statement calling for a “basket of measures” which would keep the epidemic flat and set out a number of “warning signs”.
While increasing cases are a factor, the experts said they would also be looking at positivity levels of testing, to see whether prevalence was increasing. Currently in England, positivity rates for Polymerase Chain Reaction (PCR) testing are at around 8 per cent and have been largely static since the end of July.
Crucially, last November, the Government called for a four-week lockdown when positivity rates rose to around 9.2 per cent.
Graham Medley, Professor of Infectious Disease Modelling at the London School of Hygiene & Tropical Medicine and a member of SPI-M-O, told journalists: “From a managing-anepidemic point of view, a very bad place to get into is where we have a prevalence that we consider unsustainable – either at a rate or over a long enough period – and we need to bring the prevalence down quickly.”
Likewise, SPI-M-O said it would be important to keep track of the number of cases in older people, because they are more likely to end up in hospital and die after catching Covid-19.
When last year’s snap lockdown happened, the case rate in the over60s was 185.9 per 100,000. We are currently not far off that, at 166.6 per 100,000. However, the winter peak saw far higher case rates in older people, with 445.7 per 100,000 infected.
Sir Patrick Vallance, the Government’s Chief Scientific Adviser, also said the Government would be keeping an eye on the relationship between virus cases and hospital admissions.
The vaccine rollout means that the same number of cases no longer predicts a similar rise in admissions to that seen in earlier waves.
“If you saw that changing again, that would be a cause for concern,” he told the news conference at which the Government’s winter plan was announced on Tuesday. The rate of change is also important, with Prof Chris Whitty, England’s Chief Medical Officer, warning there would be less concern about a “gradual drift up”.
Yet the Government may choose to pull the trigger before cases and admissions rise considerably, in the hope of fending off a future wave.
“When you make a move, you have to go earlier than you think you want to, you have to go harder than you think you want to, and you need to make sure you’ve got the right geographical coverage,” said Sir Patrick. However, there is a slight
‘The large-scale outbreaks that were considered feasible after taking Step 4 have not been seen’
problem with relying on advice from SPI-M-O, as the experts now admit that they misread the exit wave. All the modelling teams predicted a large summer spike that did not materialise.
“The large-scale outbreaks that were considered feasible after taking Step 4 have not been seen,” the experts said, and said predicted highs would be unlikely without waning immunity or a novel variant. The team said it did not appreciate the impact of Euro 2020 football, warmer weather, the closure of schools, or Test and Trace.
And there is more cause for optimism. Cases in Scotland are now falling again after a worrying spike, despite no interventions, possibly because of changes in behaviour in response to rising case numbers.
So, it is possible public fear of “Plan B” being introduced will be enough to keep the virus at manageable levels and therefore never need to impose it.