One is Scottish and two others English, but the three studies comparing the effects of the Omicron and Delta variants in the British population published on Wednesday point in the same direction. The first data indicate that the most recent declination of the virus results in fewer hospitalizations at this stage than the previous one.
On Wednesday, the United Kingdom, where the Omicron variant is on fire, deplored the reporting of 100,000 new cases of Covid-19. But it is from that same United Kingdom and that same Wednesday that a double ray of hope has sprung. According to several studies – two English, the other Scottish -, Omicron is certainly much more contagious than the Delta variant but at this stage results in much fewer hospitalizations.
In France, specialists are delighted by these observations, which they nevertheless welcome with a lot of nuance and caution given the galloping progress of Omicron.
Two-thirds reduction in hospitalizations according to the University of Edinburgh
We must start with an important clarification: neither of the two British studies in question has yet had time to be referred to “by peers” according to the formula. However, they go in the same direction, jointly establishing the highest contagiousness of the Omicron variant compared to Delta, the lower number of hospitalizations involved and also the effectiveness of the vaccine booster dose.
The Scottish study comes to us from the University of Edinburgh. It focused on locally registered contamination cases in November and December and on admissions (i.e. hospital stays of at least one night). She then divided the patients into two panels: the audience reached by Omicron, the audience reached by Delta. His conclusion, although balanced, is clear: “Omicron is associated with a two-thirds reduction in the risk of hospitalization for Covid-19 compared to Delta”.
“The booster dose offers significant additional protection against the risk of contracting a symptomatic form of the virus with Omicron,” the text continues.
Rarer and shorter stays
The second study is the work of Imperial College London. Covering two respective sets of 56,000 cases of Omicron and 269,000 cases of Delta declared between December 1 and 14 as noted by LCI, this work found a reduction of 20 to 25% in any type of hospitalization for Omicron compared in Delta, and a 40-45% reduction in overnight stays.
Finally, a third study by the British health agency evokes an even higher figure: there would be 70% less risk of hospitalization in the event of contamination with the Omicron variant compared to Delta, according to the BBC.
The infectious disease specialist, attached to the Parisian hospital Bichat, Yazdan Yazdanpanah, commented on these latest revelations around these variations of the virus, during a press conference of the Scientific Council held this Thursday at the end of the morning and broadcast on the Zoom application. He noticed a “35-80% drop in severity of Omicron compared to Delta.” “You could say he was less severe, but how much?” he wondered, depicting all the same a shorter duration of hospital stays, a lower oxygen requirement of the patients concerned and finally more rare transfers in intensive care.
During the same meeting, Arnaud Fontanet, epidemiologist at the Institut Pasteur, mirrored these studies with a third (posted on Tuesday on the specialized site MedRxiv), this one from South Africa, by exhuming the observation of an “80% decrease in hospitalizations for people infected with Omicron compared to Delta”.
Controversies around the consequences for the hospital
Earlier, in duplex during our show Focus First, Philippe Amouyel, professor of public health at the Lille University Hospital, had already mentioned these South African data. “We were already wondering about the data coming from South Africa”, he said, but “as the population there is much younger”, the practitioner saw in the British documents “an excellent confirmation” .
“It does not solve the problem of the dazzling contagion but compared to the risk of overloading hospitals, it allows to have a little hope”, he continued.
Not everyone, unfortunately, is of the latter opinion. Thus, Rémi Salomon, president of the Medical Commission for the Establishment of Public Assistance of Hospitals of Paris, developed a completely different picture after reading these studies on RTL.
“We must immediately weigh this good news with the extreme contagiousness of Omicron. We have never seen a virus as contagious as this one. It is spreading like wildfire. In less than three weeks, it has spread. has replaced Delta in some countries and in France, the change is being made. In the coming days it will be the majority in France, and there will be only Omicron in January “, he began , then adding: “So even if there are a little less severe cases, there will be so many cases in total that probably there will be a big, if not very big increase in the number of patients in the hospitals”.
A big cold”
For specialists, different hypotheses can already explain the relative rarity of severe forms of Covid-19 under Omicron compared to Delta: its intrusion into a population already widely vaccinated, and the youth of the preferential target of the new variant until now – that is to say the 20-40 year olds, according to Philippe Amouyel on our antenna this Thursday morning.
Generally less serious, Omicron more often goes incognito. A discretion that is not without risk or health implications. Boris Hansel, doctor and BFMTV consultant for health issues, described this pitfall in our studios.
“We don’t say it enough, but Omicron causes a lot of people to have a bad cold. The variant multiplies enormously in the upper airways. Some say that maybe that’s why we are less affected because s ‘it goes down less into the lungs, it remains very superficial “, asked the doctor in the preamble. He continued: “But it also means on a very concrete level that you have to stop blowing your nose with the same handkerchief and in front of everyone. And you have to wash your hands systematically after touching your nose.”
A prospect less distressing at least than a hospitalization.