Science

Covid-19: why has the UK postponed deconfinement?

Summer will wait… A month after the reopening of pubs and stadiums, Boris Johnson is forced to postpone his famous ‘freedom day’ by one month. The day of freedom scheduled for June 21 was to mark the end of all restrictions put in place to fight against Covid-19. A hard blow for the United Kingdom: in a few weeks, the country has gone from the stage where it was the envy of all of Europe thanks to its low number of cases and high vaccination rate, to one where it is feared a new epidemic wave that would increase the toll of the European country most affected by the pandemic (nearly 128,000 deaths according to Public health England).

However, the British situation seemed ideal just a few weeks ago: at the beginning of May the country had only 2,000 cases per day and around 100 daily hospitalizations (the lowest levels since August 2020), and the vaccination was one of the most rapid in the world with already 35 million people having received a dose and 16 million fully vaccinated as of May 5. Not to mention the arrival of sunny days which should further reduce the risk of epidemics. So why did the British have to back down and delay summer? Analyse of Sciences and the Future.

An air of déjà vu

Six months ago Boris Johnson had to do a similar backpedal. Christmas was approaching and the English were impatiently waiting to be able to gather around the tree. But the English variant (now named Alpha by the WHO) came to spoil the party, replacing the traditional strains of SARS-CoV-2 in a few weeks: according to the Sanger Institute for Genomic Surveillance, this variant represented 0.6 % of cases in England on October 31, 2020, but was already in the majority on December 19 (54.6% of cases), the day Johnson had to cancel Christmas. Today it is another variant, much more contagious than Alpha, which forces it to push back the summer: Delta (variant initially detected in India) which with a meteoric rise has increased from 0.1% of cases in England April 10 at 88% to June 5. Leading to a considerable increase in the number of new cases (around 7,000 cases per day as of June 13 against 2,000 a month earlier) which is beginning to be reflected in the number of hospitalizations, according to data from Public Health England (see graph 1).

Graph 1. Evolution of cases (blue line) and hospitalizations (red line) in the United Kingdom. Click to view larger. Credit: Nicolas Gutierrez C.

fr / politics / england-pubs-and-stadiums-reopen-Monday-despite-a-variant-Indian-preoccupant_154254 “> reopening of pubs and stadiums, Boris Johnson is forced to delay his famous’ freedom day by one month The day of freedom scheduled for June 21 was to mark the end of all restrictions in place to fight against Covid-19. A blow for the United Kingdom: in a few weeks, the country has moved from the stadium where it aroused the envy of all of Europe thanks to its low number of cases and high vaccination rate, to that where there is fear of a new epidemic wave that would increase the toll of the European country most affected by the pandemic ( nearly 128,000 deaths according to Public health England).

However, the British situation seemed ideal just a few weeks ago: at the beginning of May the country had only 2,000 cases per day and around 100 daily hospitalizations (the lowest levels since August 2020), and the vaccination was one of the most rapid in the world with already 35 million people having received a dose and 16 million fully vaccinated as of May 5. Not to mention the arrival of sunny days which should further reduce the risk of epidemics. So why did the British have to back down and delay summer? Analyse of Sciences and the Future.

An air of déjà vu

Six months ago Boris Johnson had to do a similar backpedal. Christmas was approaching and the English were impatiently waiting to be able to gather around the tree. But the English variant (now named Alpha by the WHO) came to spoil the party, replacing the traditional strains of SARS-CoV-2 in a few weeks: according to the Sanger Institute for Genomic Surveillance, this variant represented 0.6 % of cases in England on October 31, 2020, but was already in the majority on December 19 (54.6% of cases), the day Johnson had to cancel Christmas. Today it is another variant, much more contagious than Alpha, which forces it to push back the summer: Delta (variant initially detected in India) which with a meteoric rise has increased from 0.1% of cases in England April 10 at 88% to June 5. Leading to a considerable increase in the number of new cases (around 7,000 cases per day as of June 13 against 2,000 a month earlier) which is beginning to be reflected in the number of hospitalizations, according to data from Public Health England (see graph 1).

Graph 1. Evolution of cases (blue line) and hospitalizations (red line) in the United Kingdom. Click to view larger. Credit: Nicolas Gutierrez C.

Higher risk of severe forms

According to a preliminary analysis by this institute, this Delta variant would double the risk of hospitalization and severe forms. This higher risk of severe forms seems to be confirmed by looking at hospitalization data in the United Kingdom: the intensive care unit occupancy rate (with mechanical ventilation) appears to be increasing more rapidly than the hospitalization rate, with 31% of increase in the last two weeks (since May 27) against 25% for hospitalizations. For the moment, these changes are not yet visible on deaths (see graph 2).

Graph 2. Hospital situation in the United Kingdom: people hospitalized (in blue), people in intensive care (in red) and dead people (in yellow). Click to view larger. Credit: Nicolas Gutierrez C.

Will France follow the same path?

In France, epidemiological data are encouraging and have continued to decrease since the end of confinement. Still, the Delta variant appears to be rising as quickly as in England, just a few weeks late. According to the Minister of Solidarity and Health Olivier Véran, this variant currently represents between 2 and 4% of new cases, a level similar to that in England on April 24. If we compare the current situation in France to that observed in the United Kingdom on that date, two countries with comparable populations (66 million Britons against 68 million French), we see that the epidemic was better. controlled in the British than in us, with fewer new cases per day (2,500 against 4,000) and less than half of daily hospitalizations (123 against 291 in France). In terms of vaccination, the situation was comparable to that currently in France, with slightly more adults fully vaccinated here than there on April 24 (30% against 25%) (see graph 3).

Graph 3. Epidemic and vaccination situation in France on June 13 (red) and the United Kingdom on April 24 (blue). The UK vaccination rate is given only for those over 18. The French data communicated by Public Health France, which concerns the entire population, have been recalculated with data from INSEE in 1er January 2021 to take into account only people over 18 years old. Click to view larger. Credit: Nicolas Gutierrez C.

The French situation is therefore not much more favorable than that of the United Kingdom before the rise of the Delta variant. But it is impossible to predict whether the trajectory of this variant will follow the same exponential curve as in the UK. The Élysée seems convinced that this will not be the case. It only remains for us to take advantage of the summer, carefully, and wait.

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