Omicron subvariants drive up Covid hospitalizations in Europe and US

Hospital admissions are rising in Europe and the United States as highly transmissible variants of Covid-19 lead to infections, but the resulting illness is less likely to be severe or cause death than during waves previous years, according to data analyzed by the Financial Times and health experts.

The number of new Covid admissions increased by 40% last week in France, 34% in England and more than 20% in several other European countries. The wave was powered by the BA.5 Omicron sub-variant.

Maurizio Cecconi, president of the European Society of Intensive Care Medicine, said cases were increasing in France, Italy and Germany. However, he added that cases had dropped in Portugal, which was at the forefront of a fifth wave of Covid in Europe.

The rate of increase in hospital admissions in the United States is currently slower than in Europe, at 6%. This reflects the decline of the BA.2 variant in the US, analysis of the FT data suggests. But as the BA.5 variant becomes dominant, the overall growth rate is expected to accelerate.

BA.4 and BA.5 currently account for about half of all infections in the United States, estimated Dr. Robert Wachter, professor and chair of the department of medicine at the University of California, San Francisco (UCSF).

Despite signs that variants are more capable than predecessors of evading protection from vaccines and past infections, FT analysis found that in countries experiencing BA.5 waves, deaths only showed only very small increases in hospitalizations, which themselves remain well below record highs. .

Several experts said those with the disease were less likely to require treatment in intensive care than in previous phases of the pandemic and that a greater proportion only tested positive incidentally after being admitted for reasons other than during previous waves.

Cecconi, who is an intensive care doctor in Italy’s Lombardy region, said “very few” people were admitted to intensive care. He added that in his region, between 10 and 15% of patients needed intensive care at the start of the pandemic in March 2020. By the fourth wave, this figure had dropped to 8% and currently “we are probably between 2 and 3 %”. sick people. . . so it’s a very different wave from the past”.

He said it was unclear whether the lower number of ICU admissions suggested BA.4 and BA.5 were inherently milder sublines, or just that two years into the pandemic. , the majority of people were either vaccinated or had some protection against serious disease through previous infection. . “The population is very different. It is very difficult to find people who are completely naive to the virus or immunity from vaccination, and that helps a lot [in reducing] the number of very sick patients,” he added.

In the United States, Wachter also said there was evidence that the new variants could produce less severe disease. Six months ago, about two-thirds of UCSF patients who tested positive for Covid-19 had been admitted due to complications from the infection, while a third had only been discovered so fortuitous, he said. The split was now 50:50, suggesting fewer people were becoming so ill with the virus that they needed hospital care.

The FT analysis suggests that most of each new variant’s advantage over older variants now comes from its ability to evade immunity, rather than greater transmissibility. With different combinations of varying and vaccine-specific immunity in different places, the analysis also suggests it is difficult to use data from one country to predict what is happening elsewhere.

In South Africa, where the latest Omicron releases first took off, the BA.4/BA.5 wave was less than half the size of its original Omicron wave last winter, according to the data. In Denmark, whose BA.2 wave was by far the largest of the pandemic, the BA.5 wave appears to be around a fifth of the previous peak. However, UK hospital admissions are already 77% of the way to their 2022 peak and still rising.