(CNN) — European countries are experiencing a significant increase in COVID-19 cases driven by highly infectious sub-variants of the omicron variant, raising fears of a new global wave of the disease as immunity wanes and travel season begins. boreal summer.
The European Center for Disease Prevention and Control (ECDC) warned last week that “the reported growth advantage for BA.4 and BA.5 suggests that these variants will become dominant” in throughout the European Union, and will likely lead to an increase in cases.
Infections are on the rise in multiple countries, including Portugal, Germany, France, Greece, Austria, Italy, Switzerland and Spain, according to Oxford University’s Our World in Data (OWID) project, which tracks the pandemic.
New studies have shown that the BA.4 and BA.5 subvariants of omicron have a growth advantage over earlier variants and appear to be good at evading the immune system. In other words, neither previous infections nor vaccinations provide particularly strong protection against the subvariants, so they are becoming the dominant strains. BA.4 and BA.5 do not appear to lead to more severe disease, but, as in previous waves, the increase in cases could lead to increased hospitalizations and deaths, according to the ECDC.
The potential impact of one of the sub-variants, BA.5, is most evident in Portugal, where it has driven a significant increase in Covid-19 infections. This increase seems to have leveled off, but is still higher than in other countries. On Tuesday, the country recorded a daily average of 1,332 new cases per million inhabitants in the previous seven days, the fifth highest rate in the world. Compared to Germany’s 760 and France’s 747, according to OWID.
The number of people hospitalized in Portugal, at 1,896, is almost as high as during the original wave of omicron in January. The BA.5 strain became dominant in the country in May, shortly after it was first detected in late March, according to Portugal’s National Health Institute (INSA). As of June 5, it represented 84% of all covid infections in that country.
In France, the number of new cases per million people has nearly tripled since the beginning of the month, and hospitalizations are rising for the first time since early April. According to the public health agency Santé Publique France, in its latest update, the BA.5 subvariant accounted for 24% of sequenced cases in the week of June 6, compared to 18% the previous week.
France’s vaccination chief, Alain Fischer, said on Wednesday that the question was not whether the country was facing a new wave of the virus, but how intense it might be, and was personally in favor of reinstating some restrictions to limit the spread.
“The epidemic is accelerating again and it is completely unexpected in this season,” Dr. Benjamin Davido, an infectious disease specialist at Raymond-Poincaré hospital outside Paris, told French radio on Sunday.
“With the new omicron sub-variants (BA.4 and BA.5), which are between 10% and 15% more contagious, the epidemic has found a new energy, even though we have passed the winter,” said Davido , adding that the lifting of almost all restrictions, such as the use of masks in public transport and on planes, combined with the loss of immunity, posed a real threat.
Davido and other health experts have warned that France’s hospitals could fill up during the summer unless vulnerable people and those over 60 get booster shots as soon as possible. However, although hospital admissions in the country are increasing, it remains unclear whether this is because the BA.5 subvariant is more transmissible or because it is evading waning immunity.
In the UK, where cases and hospitalizations are rising sharply, the start of a new wave also appears to be driven by BA.4 and BA.5, according to the Office for National Statistics (ONS). ). The latest data from the ONS, published on June 17, shows that Covid infections increased by 43% from one week to the next, according to the British Medical Journal (BMJ), a specialized peer-reviewed medical journal.
Writing in the BMJ, Christina Pagel, a professor of operations research at University College London, said: “We will be the first major country (but not the last) to have a wave of BA.4.5, having had two previous waves of BA.4.5.” This means that we could get some additional protection from the high number of infections that we had in March, which will reduce the size of this next wave, however, a significant part of the country will be sick, especially since [la inmunidad de] reinforcements is dwindling.”
It seems that the United States is not far behind. The latest data from the US Centers for Disease Control and Prevention (CDC) shows that the BA.4 and BA.5 subvariants caused more than one in three covid-19 infections. 19 in the United States last week. Subvariants are also expected to become dominant in the country in the coming weeks.