Guido Silvestri is fed up with the alarmist news on the Omicron variant. The virology professor of Emory University in Atlanta is known for his calm tones and which do not go well with the constant warnings issued by TV virologists and once again with a long post on Facebook he tried to report the reality of the facts about the mutation of Covid arrived from South Africa. These are his words: “While the mainstream media are raving about ‘Tsunami Omicron’ and the ‘alternative’ ones are raving about toxic vaccines and the dictatorship of scientists, there are three important facts that are emerging about the new variant that deserve serious discussion. In my small way I continue to try, despite the thousand commitments and tiredness, because I still believe in the hope of being able to make a contribution, perhaps even a very modest one, so that my distant country can come out of this wave of collective hysteria that seems to have taken it in these last weeks “.
These are the facts listed by Silvestri:
1. The calculated lethality of COVID-Omicron (in technical jargon: Infection Fatality Rate, ie 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 400,000 cases speaks of 0.26% of lethality, compared to 2.5% -4.0% of the previous waves. This despite the fact that only 26.3% of the population is fully vaccinated (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).
2. The news emerged of the study by the National Institute for Communicable Diseases of the South African government directed by Nicole Walter and Cheryl Cohen, according to which the risk of hospitalization in patients who have contracted Omicron is 20% of that observed in patients who had 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 history for having contracted the infection previously [in questo senso lo studio Imperial che alcuni citano non è rilevante per ovvii motivi statistici, in quanto chiaramente underpowered per provare la “null hypothesis” — ed oggi lo stesso Imperial, con più dati, vede una riduzione del rischio del 45%, e lo studio scozzese indica una riduzione del 67%] .
3. 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, has recently been published, 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 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 ”.