Winter hospitalisations will increase

Eight-week scenarios for daily hospital admissions in England

R = 1.1 – green, (is much more possible through a range of many different situations)

R = 1.5 – blue (also likely)

R = 2.0 – red (a possible outcome, but highly unlikely)

Hospitalisations likely to rise, 2,000 to 7,000 per day next month

Government's Plan B if the NHS faced unsustainable pressure

Sir Patrick Vallance

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 have to make sure you have got the right geographical coverage

SPI-M-O: Consensus Statement on COVID-19 (SAGE)

Scientific Pandemic Influenza Group on Modelling (SPI-M)

The UK is currently experiencing high prevalence and likely entering a period of growth

A time of significant uncertainty

School holidays

Possibility for further evidence to emerge on the duration of immunity against COVID-19

Possibly broader, longer peaks than those originally estimated

Potential for another large wave of hospitalisations

Increasing cases remain the earliest warning sign that hospital admissions are likely to rise

Clear consensus that continued high levels of homeworking has played a very important role in preventing sustained epidemic growth

Highly likely that a significant decrease in homeworking in the next few months would result in a rapid increase in hospital admissions

If enacted early enough, a relatively light set of measures could be sufficient to curb sustained growth

Current epidemic estimates

UK (Health Security Agency)

R in England is between 0.9 and 1.1

Growth rate is between -1% and +1% per day

It is unclear how high prevalence and admissions may go without intervention.

Reflections on modelling Step 4 of the Roadmap

After step 4 of the Roadmap on 19th July

Factors

Schools closed for summer

Changes in behaviour

Changes in mixing patterns have been more gradual

the population has not reduced their cautious behaviours as dramatically as was considered possible

Warm weather

More sunshine

Large proportion of the population isolating after being identified as a contact of a case

Imperial’s modelling

‘pessimistic scenarios’ which assume a three-year average duration of infection-induced immunity

Does not consider any variants of concern beyond Delta

Peaks occurring in October to December instead of August to October

Highest levels seen in Step 4 Roadmap scenarios

Will not be reached without waning immunity

or a novel variant emerging

Behaviour was assumed to be consistent across age groups

If those at higher risk of morbidity and mortality from COVID-19 take greater precautions,

levels of hospital admissions and deaths could be lower than those seen in the Roadmap modelling

Vaccine effectiveness estimates continue to be refined

There is now evidence of waning vaccine effectiveness particularly 140 days after the second dose

Those individuals vaccinated in late 2020 and early 2021 will have less protection in the coming months

Third doses and booster vaccinations, which are able to reverse waning of protection, will limit the impact of waning immunity

Policy clarification

Third doses for all over 50 or at increased risk

UK Chief Medical Officers, advised vaccination aged 12 to 15

If acute COVID-19 combines with other pressures

Long COVID

Other infectious diseases, influenza, RSV, norovirus

Co-infection of SARS-CoV-2 with other diseases

Medium-term projections and scenarios

They are neither forecasts nor predictions

Cannot fully reflect recent changes in transmission that have not yet filtered through into surveillance data.

Even in the R =1.1 scenario, up to 2,000 a day) in England

For a potentially protracted period of time

this could lead to a difficult few months for the health and care sector

Warning signs

Number of cases

Positivity rate

Age profile of those infected

Declining immunity, new variant, radical behaviour change, 5 million unvaccinated (John)

Timing of interventions

A basket of measures, light enough to keep the epidemic flat, would be sufficient if enacted when hospitalisations were at a manageable level.

If the epidemic were allowed to continue to grow until hospitalisations were at a level that needed to be rapidly reduced,

much more stringent measures would be needed to bring prevalence down quickly.

The nature of interventions

If enacted early enough, a relatively light set of measures could be likely be sufficient to curb sustained but slow growth