In the fight against the coronavirus, will optimism be able to make a comeback? Two studies carried out in Great Britain and published on Wednesday show that infections with the variant Omicron are less likely to cause hospitalizations compared to the Delta variant. These therefore confirm a trend first observed in South Africa .
These preliminary studies, one coming from from Scotland and the other from England, were welcomed by the experts, who were however cautious and stressed that the high transmission rate of the variant could still result in more serious cases. “This is good news with nuances – with nuances because these are early observations, they are statistically significant, and we are showing a reduced risk of hospitalizations ”, for his part explained a co-author of the Scottish study, Jim McMenamin.
Scottish research looked at the cases recorded in November and December, and grouped them into two groups: Delta on one side, Omicron the other. According to this study, “Omicron is associated with a two-thirds reduction in the risk of hospitalization for Covid – 19 compared to Delta”. It has also been shown that a booster dose provides substantial additional protection against symptomatic infection. However, this is a small study that did not examine any hospitalized person and under 60 years, but the authors adjusted these limits using statistical methods.
The evaluation of the peer review still to be done
The other study found a reduction from 20 to 25% in any type of hospitalization for Omicron compared to Delta, and a reduction from 25 to 45% in overnight stays. “If the reduction in the risk of hospitalization with the Omicron variant is reassuring, the risk of infection remains extremely high,” warned Azra Ghani of Imperial College London, on the other hand, who co-wrote the English study. “By adding the booster dose, the vaccines continue to offer the best protection against infection and hospitalization.”
Neither study has yet been peer reviewed, but they add to a growing body of evidence on this variant. It is not clear whether the decrease in the rate of severe cases observed with Omicron is due to the characteristics of the variant or if it appears less severe because it encounters populations with more immunity because of being vaccinated or having been ill with Covid. -19 in the past. “This news does not take away from the extraordinary spread of this variant in the population, and the fact that even a small proportion of people requiring hospital care for Covid could turn into very large numbers if the rate of community spread continues. to increase ”, warned Penny Ward, professor of pharmaceutical medicine at King’s College London, who did not participate in the research.