The latest ONS data shows clearly that after the September surge, cases took a downward turn in October.

Covid numbers down, but which way next?

The number of Covid-19 infections has gone into decline after pushing upwards during most of October. But another upward surge looks possible this month as faster-growing sub-lineages of the dominant Omicron variant account for an increasing proportion of new cases. Text by Nick Terdre, research and graphics by Russell Hall.

The recent upward trend in new Covid-19 cases went into reverse in late October, with substantial falls week-on-week for the week ending 31 October in Rother (down 30.2%), East Sussex (down 31.4%) and England (down 30.8%), according to the UK Heath Security Agency (UKHSA). In Hastings the decline was a more modest 4.8%.

The downturn may be explained by roll-out of the autumn booster, and perhaps the unseasonably warm weather during October. By 2 November 49% of Hastings residents aged 50 or over had been given a new booster, and 55.9% of those in Rother.

The estimated R value – reproductive rate – calculated from the UKHSA data was below 1 for Hastings, Rother, East Sussex and England, also an indication of falling numbers. For Hastings however it was slightly up on the previous week, while in Rother, East Sussex and England it continued to fall. This could be an early sign that numbers will soon turn up again in Hastings.

The downward trend is also borne out by the latest Office for National Statistics (ONS) weekly survey, which lags the UKHSA data but is taken as a more accurate picture of the reality on the ground. To put the current situation into context, October’s peak is well below those recorded in January, April and July — see main graph.

Positivity rates – the proportion of positive outcomes in tests – calculated from the ONS survey data indicate that on 24 October one in 35 in the South East tested positive, down from one in 30 seven days previously, the same proportion as for England, which was unchanged, while rates were lower still in London, at one in 40, also unchanged.

There has also been an improvement on the East Sussex hospital front, with admissions in the week ending 31 October down by two thirds from 145 to 48. On 2 November there were 62 Covid-19 positive patients in hospital, down from 98, occupying 7.6% of the open (available) beds, against 12.1% a week before; at this date there were no Covid-19 patients on mechanical ventilation.

However in the week ending 21 October, when infections were still increasing, there were 10 deaths in East Sussex with Covid on the death certificate, up from six the previous week.

While the number of infections is falling, there are reasons for supposing this may be a temporary blip before they start rising once more. A number of sub-lineages of the dominant Omicron variant are proving increasingly effective at dodging immunity, whether natural or vaccine-induced. The BQ.1 group of sub-lineages was responsible for 29% of all sequenced cases in the two weeks to 3 November, up from 10.6% on 10 October and just 3.6% on 26 September .

Not all cases are sequenced, so the true proportions may vary somewhat, but these numbers provide a useful snapshot of the relative performance of the different variants and their sub-lineages.

This Muller graph shows the various types of the Covid-19 virus which have been principally responsible for causing infections in the UK since the early days of the pandemic. Since late last year, different strains of the Omicron variant have been dominant, and this role may soon be taken by the Omicron BQ.1 sub-lineages, which can be seen growing fast in the bottom right-hand corner of the graph.

While Hastings Borough Council is still encouraging eligible residents to get the autumn booster, advice and comments from the East Sussex director of health Darrell Gale have been missing for some time, even when infections were rising.

Last week saw the independent inquiry into the UK’s preparedness and responses to the Covid-19 pandemic move into a second phase, in which it has launched a listening exercise to tap into the experience of individuals affected by Covid. It will also examine the actions taken, or not taken, by government, health authorities and other key players, in order to learn lessons for future pandemics.

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