The SAGE group of experts suggests “a basket of measures” which could keep COVID-19 under control if enacted early enough by the government.

First published in September 2021.

Newly published modelling from government scientific advisers on the SAGE advisory committee warns PM Boris Johnson and his government not to wait too long before bringing back restrictions to protect people from a winter surge of coronavirus infections.

In their latest Consensus Statement, the group of experts told the government:

“The UK is currently experiencing high prevalence and likely entering a period of growth as a result of changes in behaviour. It is also a time of significant uncertainty given the scope for increased transmission after the end of the school holidays, the possibility for further evidence to emerge on the duration of immunity against COVID-19, and several policy areas likely to become clearer.”

Potential new large wave of hospitalisations

“Until uncertainties resolve and changes in transmission are fully reflected in data – likely in three to four weeks’ time – [SAGE]’s medium-term scenarios can be used to consider the next couple of months. These suggest there is the potential for another large wave of hospitalisations.

“While the relationship between cases and hospitalisations has changed due to vaccination, increasing cases remain the earliest warning sign that hospital admissions are likely to rise. It also remains the case that the earlier that interventions are brought in to curb growth, the lower prevalence is kept, reducing the direct COVID-19 burden and reducing the risk of needing more stringent measures to quickly reduce transmission.

“There is a clear consensus that continued high levels of homeworking has played a very important role in preventing sustained epidemic growth in recent months. It is highly likely that a significant decrease in homeworking in the next few months would result in a rapid increase in hospital admissions.”

Light set of measures could work if brought in early enough

If enacted early enough, a relatively light set of measures could be sufficient to curb sustained growth. During a period of sustained epidemic growth, however, the more stringent the measures introduced, the shorter the duration needed for the measures to be in place to reduce to a given prevalence.

“Prevalence has remained high for some weeks, and hospital admissions in older population have increased, albeit relatively slowly from a low base. It is unclear how high prevalence and admissions may go without intervention. While it is too early to observe in the data, it is possible that transmission will increase as the majority of schools have now returned in England and many adults are returning to the office after an extended period of working from home.”

Peak could happen by December

“It is likely that the future trajectory of the epidemic may be some combination of the Step 4 Roadmap scenarios but with a delay of any peak, for example with peaks occurring in October to December instead of August to October.”

Booster jab necessary to protect early vaccinated people

There is now evidence of waning vaccine effectiveness, particularly 140 days after the second dose; this was not considered in most scenarios conducted before Step 4 was taken. Those individuals vaccinated in late 2020 and early 2021 will have less protection in the coming months, an issue exacerbated by lower effectiveness in those individuals who may be older or vulnerable as already discussed, many of whom were vaccinated in this period. Third doses and booster vaccinations, which are able to reverse waning of protection, will limit the impact of waning immunity.”

A very difficult winter ahead

With the current levels of high prevalence combined with unknown behaviours, the burden on health and care settings could rise very quickly. If acute COVID-19 combines with other pressures, such as Long COVID, other infectious diseases (influenza, RSV, norovirus, etc.), or co-infection of SARS-CoV-2 with other diseases increases morbidity, it could be a very difficult winter ahead.

“While the relationship between cases and hospitalisations has changed due to vaccination, increasing cases remain the earliest warning sign that hospital admissions are likely to rise.”

A basket of light measures could work

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 (and therefore more disruptive) measures would be needed to bring prevalence down quickly.

“As well as encouraging home working, more light touch measures could include clear messaging that recommends people acting cautiously, more widespread testing, a return to requiring all contacts of cases to isolate, and more mask-wearing.

“Given a high proportion of susceptible people are in younger age groups, measures targeted towards them are likely to have a disproportionately large effect on prevalence.” 

Going further:


PMP News reporting.


[This piece was first published in PMP Magazine on 14 September 2021.]

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