Variant Omicron, Silvestri: “Getting out of a wave of collective hysteria”

On Omicron it is necessary to recover “a serious, calm, pragmatic and fact-based discussion”. This is the invitation that the Italian virologist Guido Silvestri, lecturer in the USA at Emory University in Atlanta, makes on the basis of the latest data emerged on the new variant of Sars-CoV-2. Results that the scientist summarizes in a post on Facebook, “in the hope of being able to make a contribution, perhaps even a very modest one – he writes – so that my distant country can come out of this wave of collective hysteria that seems to have taken over in recent weeks”. “While the mainstream media are raving about the ‘Omicron tsunami’ and the ‘alternative’ ones are raving about toxic vaccines and the dictatorship of scientists – explains the founder of the social page ‘Pills of Optimism’ – there are three important facts that are emerging about the new Omicron variant. which deserve serious discussion. ” First fact: “The calculated lethality of Covid-Omicron (in technical jargon: Infection Fatality Rate, that is the ratio between the number of deaths and the number of cases observed) seems much lower than that of the previous variants. The data from South Africa on almost 400 thousand cases speaks of 0.26% of lethality, compared to 2.5-4% of the previous waves. This despite the fact that the population is fully vaccinated only at 26.3% (42% of adults). In accordance with this observation, the pressure on intensive care in South Africa, a country of 60 million inhabitants, remains low, with a total of 546 beds occupied (much less than in Italy) “. According to fact highlighted by Silvestri:” The news of the National study is today Institute for Communicable Diseases of the South African government headed by Nicole Walter and Cheryl Cohen, according to which the risk of hospitalization in patients who have contracted Omicron is 20% of that seen in patients who have contracted Delta (to be clear , if Delta’s risk of going to hospital was 5%, it would be 1% for Omicron). Although the study uses historical controls (Delta has disappeared from South Africa now), the analysis was done after having corrected for age, sex and positive medical history for having contracted the infection previously “. Third fact recalled by the virologist:” It is recent days the very interesting study by the LKS Faculty of Medicine at the University of Hong Kong, directed by Michael Chan Chi-wai and John Nicholls, according to which the Omicron variant is more effective in infecting the cells of the upper respiratory tract and bronchi, but less efficient in infecting those of the deep lung tissue. This study could represent the mechanistic basis of the lower clinical severity observed in South Africa, as interstitial pneumonia with diffuse alveolar damage and consequent systemic complications is the central element in the pathogenesis of severe Covid “. Silvestri’s hope is that” these data can be used to reshape our legislative and communication approach to the pandemic. “