Daily Covid cases could reach 1,200 if social contacts ‘step change’ in May, Nphet warns

Scenarios presented to Government suggest close indoor contact high risk for eight weeks

A range of scenarios have been presented to Government by the National Public Health Emergency Team (Nphet) lead by chief medical officer Dr Tony Holohan. Photograph: Colin Keegan/ Collins Dublin

A range of scenarios have been presented to Government by the National Public Health Emergency Team (Nphet) lead by chief medical officer Dr Tony Holohan. Photograph: Colin Keegan/ Collins Dublin

 

Cases could climb as high as 1,200 per day, with around 101,000 in total between now and the end of September, if a “step change” in close social contact takes place in May, the Government has been warned.

A range of scenarios have been presented to Government by the National Public Health Emergency Team (Nphet).

It is understood they show if the R number, which tracks how quickly the pandemic is spreading, increases to 1.5 in the period following May 10th, daily case counts would peak at 1,100 to 1,200 per day in July, and a possible 101,000 new cases over the same period.

Ministers were told that if a phased approach was adopted in the weeks ahead, such a scenario was the upper limit of what was likely, with risk significantly reduced if increased close social contact is put back until June 7th.

In that scenario, where R increases to 1.25 from May 10th and to 1.5 from June 7th, cases and hospitalisations will still increase, but at a lower level before being suppressed by vaccination during the summer.

It is understood that these projections are lower than similar models run in late March, suggesting that the delay in reopening of April, which contributed to lower case counts and less transmission. The scenarios suggest a reopening involving close indoor contact will remain high risk for at least the next eight weeks.

Surge

Separate modelling in the letter suggests that allowing significant levels of close mixing, similar to those seen during July and August last year, from May 10th would result in another surge, putting significant pressure on the hospital system.

In that scenario, cases would be as high as 7,000 per day by July, with an estimate of around 385,000 cases between May and September, the Government was warned last night.

Such a scenario presumes the R number would grow to the level of around 1.9, driven by levels of close contact similar to those in July and August last year, when a higher level of indoor socialisation and mixing was allowed. Even with vaccination, it could lead to a significant surge, resulting in 10,000 admissions to hospital.

However, modelling shared with the Goverment shows an increase in the R number to a similar level in early July almost totally avoids a surge, due to the impact of vaccination, suggesting a more widespread reopening at that stage could be done with significantly lower levels of risk.

Uncertainty

It is understood that in its letter, Nphet also flagged significant uncertainty around the direction of the pandemic. Ministers were warned that more data is needed on the transmissability of the B117 variant, as well as close study of phased re-opening in May and June alongside the vaccination programme, before predictions can be made about what could happen with a wider reopening and indoor social contact later in the summer.