July 12, 2021

expert reaction to modelling documents looking at step 4 of the roadmap, published today as part of the SAGE document publication

The latest batch of SAGE documents, including modelling papers looking at step 4 of the roadmap out of lockdown, have been published this afternoon.

Commenting on the Imperial College London modelling (please note Dr Anne Cori is one of the authors of that modelling):

Dr Anne Cori, Lecturer in Infectious Disease Modelling, Imperial College London, said:

“Our results suggest that the lifting of restrictions on 19th July will lead to a third wave of infections in England.  But its magnitude, and that of the corresponding wave of hospitalisations and deaths, remain highly uncertain.  A number of factors are at play: vaccine coverage and effectiveness, persistence of immunity over time, but also the extent to which individuals keep being cautious after 19th July (e.g. keep working from home or wearing masks).  Increases in any of these will help reduce the epidemic burden.”

Commenting on the SPI-M summary document:

Dr Thomas House, Reader in Mathematical Statistics, University of Manchester, said:

“This document reflects the consensus view of several groups and individuals attending the SPI-MO modelling sub-committee of SAGE.  This shows the potential for a significant additional wave of hospitalisations and deaths due to COVID, but at the same time considerable uncertainty in what the most likely scenario is.  As we have seen at several points in the pandemic, the potential of factors such as hospitalisations and deaths to grow exponentially – meaning that they double after a certain number of days – means that such a new wave can quickly cause significant problems from a relatively low baseline.  Therefore, as the statement suggests, it is likely to be a good idea to have a plan in place for such an eventuality, while hoping that it does not come to pass.”

Imperial College London document: ‘Evaluating the Roadmap out of Lockdown for England: modelling the delayed step 4 of the roadmap in the context of the Delta variant’.

SPI-M-O summary document: ‘SPI-M-O: Summary of further modelling of easing restrictions – Roadmap Step 4 on 19th July 2021’.

Declared interests

Dr Anne Cori: “Dr Anne Cori is on SPI-M and part of the Imperial group who put together some of the modelling published today.  Taught on a modelling course for Pfizer a few months ago.”

Dr Thomas House: “I have a conflict of interest in membership of SPI-MO, but I’m not speaking on behalf of that committee.”