It’s confirmed: Omicron causes less severe forms than Delta

Two studies conducted in the UK and published on Wednesday suggest that infections with the Omicron version of COVID-19 are less likely to lead to hospitalization than the delta version, confirming a trend first observed in South Africa. does.

These initial studies – one from Scotland, the other from England – were welcomed by experts, who were however cautious and stressed that the high transmission rate of the variant could still result in more severe cases.

“What we are saying is good news with specifics – with specifics because these are early observations, they are statistically significant and we show a low risk of hospitalization.”Jim McMenamin, co-author of the Scottish study, told reporters in a phone call.

The Scottish research looked at cases recorded in November and December, and divided them into two groups: Delta on one side, 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”, It also showed that a booster dose provided significant additional protection against symptomatic infection.

This is a small study that did not look at hospitalizations and anyone younger than 60 years of age, but the authors said they adjusted for these limitations using statistical methods.

Another study from England found a 20-25% reduction in any type of hospitalization and a 40-45% reduction in overnight hospitalization for Omicron, compared to Delta. “enter”,

The Scottish study only looked at admissions.

“While the low risk of hospitalization with the Omicron version is reassuring, the risk of infection is very high”Ajra Ghani of Imperial College London, who co-authored the English Studies. “By adding booster doses, vaccines continue to provide the best protection against infection and hospitalization.”

Neither study has yet been peer-reviewed, but they add to a growing body of evidence on Omicron. It is not clear whether the reduction in the rate of severe cases seen with Omicron is due to the characteristics of the variant or if it appears to be less severe as it comes against populations that are more immune because they have been vaccinated or are ill. are covid. in the past.

“This news is not far from the extraordinary spread of this type in the population, and the fact that if the rate of community spread continues, even a small proportion of people needing hospital care for Covid could grow into very large numbers. Is.”warned Penny Ward, Professor of Pharmaceutical Medicine at King’s College London, who was not involved in the research.