The SAGE meeting (85) considered
modelling (Warwick Uni) of the hospitalisation levels (and worse) for England assuming relaxation of (most of) the restrictions in stages from March to June.
Executive Summary (very precised, easy read at link: 2/3 of a page)
- Models impact of relaxations in England
- Will be a third wave with a summer (July/August) peak of hospitalisations: severity depends on many factors/assumptions/uncertainties
- Uncertainties:
- transmission levels at each relaxation step;
- seasonality effect (both on virus and on outside/inside and ventilation behaviour;
- vaccine efficacy (in particular preventing transmission),
- uncertainty in the population-level immunity due to infection,
- confounding behaviours, both beneficial and detrimental (extended caution even after relaxations; restriction fatigue, post-vaccination ‘freedom’),
- Lower than expected vaccine efficacy or higher transmission (R) after Step 4 (21 June ish) lead to larger wave; while seasonality acts to suppress the summer wave.
And a Tim Spector update:
- Not accounting for waning immunity (natural infection or vaccination induced),
- Nor accounting for the chance of vaccine escape variants.
View attachment 582635
And finally, the modelling suggests that during this summer wave, of whatever severity, at its peak about 80% of the resultant deaths will be people who have received both doses of vaccine (45% over 80 and 35% 50-79). ETA: Important to recognise that this does not represent a failure of vaccination, but simply indicates that with high population coverage there will be fewer hospitalised cases, and a higher proportion of these individuals will have been vaccinated.
There were two other models informing SAGE (from Imperial College and the London School of Hygiene and Tropical Medicine (LSHTM)) but Warwick University produced the better one last time. Serves to illustrate the caution which the next few months will demand.
