Two studies in Great Britain showed that infection with the Omicron variant of Covid-19 is less likely to cause hospitalization than the delta variant, confirming a trend first observed in South Africa.
Those preliminary studies published on Wednesday – one from Scotland and the other from England – were welcomed by experts, but they were cautious and stressed that the high rate of transmission of the virus could lead to more serious cases.
“What we’re saying is that this is good news with nuances – with nuances because these are early observations, they are statistically significant and we show a lower risk of hospitalization,” Scottish study co-author Jim McMenamin told reporters on a phone call.
The Scottish research looked at cases recorded in November and December, grouping them into two groups: delta on one side, and omicron on 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.” The booster dose has also been shown to provide significant additional protection against symptomatic infection.
This is a small study that did not look at anyone in hospital and under the age of 60, but the authors said they adjusted these limits using statistical methods.
The second study, from England, found a 20-25% reduction in any type of hospitalization for Omicron compared to Delta, and a 40-45% reduction in overnight stay (“admission”). Only the Scottish study considered admission.
“While reducing the risk of hospitalization with an omicron is reassuring, the risk of infection is still very high,” warned Azra Ghani of Imperial College London, who co-authored the study in English. “By adding the booster dose, the vaccines continue to provide the best protection against infection and hospitalization.”
Neither study has yet been reviewed, but they add to a growing body of evidence about Omicron. Il n’est pas clair si la diminution du taux de cas graves observée avec Omicron est due aux caractéristiques du variant ou s’il semble moins sévère parce qu’il se heurte à des populations davantage immunisées avacantes parce du é que from the past.
“This news does not detract from the unusual prevalence of this variant in the population, and the fact that even a small percentage of people who need hospital care for Covid could turn into very large numbers if the rate of community prevalence continues to increase,” warned Penny Ward, a professor. Pharmaceutical Medicine at King’s College London, which was not involved in the research.