“At the moment – underlines the ISS – there are still limited data that indicate a significant reduction in the vaccine efficacy against the symptomatic disease from Omicron compared to that from Delta after two doses of Pfizer or AstraZeneca vaccine“.
Poor efficacy after first and second dose – A study not yet peer-reviewed reports a loss of efficacy of the primary cycle (first and second dose) with respect to hospitalization, although to a lesser extent than in symptomatic disease. To detect the infection even in the presence of Omicron are the normal tests already in use based on Pcr, the direct rapid antigenic ones that are directed towards the nucleocapsid protein and retain their diagnostic capacity.
Many monoclonal antibodies are less effective – Regarding therapies, the ISS explains that corticosteroids and IL6 antagonists remain effective in the treatment of severe patients. While some studies observe a loss of efficacy of many monoclonal antibodies due to the mutations present in the Omicron variant.
Greater transmissibility Consistent evidence shows that Omicron has greater transmissibility than the Delta variant in countries with documented community transmission, with a doubling time of 2-3 days and that Omicron could become the predominant variant in a few weeks.
From the first data, the risk of hospitalization is lower Meanwhile, data on the clinical severity of patients infected with Omicron are still preliminary and suggest a reduction in the risk of hospitalization for Omicron compared to Delta. However, the risk of hospitalization is only one aspect of the severity of the disease: “More data from different countries is needed to understand how the other indicators (the use of oxygen, mechanical ventilation or mortality) are associated with this variant in severe cases.
It is currently unclear to what extent the observed reduction in hospitalization risk can be attributed to immunity from previous infections or vaccines, or to what extent Omicron may be less virulent. However, recalls the Higher Institute of Health, all variants of Covid can cause serious illness or death, especially in the most vulnerable people by age or physical condition.
The anti-Omicron measures remain the samee – Finally, the ISS recommends strategies to the population to reduce the spread of the virus: reaching the highest possible vaccination rates remains the main weapon to reduce the risk of Covid transmissions and significant peaks in cases, as well as to reduce the likelihood of new variants emerging. The measures remain the same also for this variant: keep a distance of at least one meter from the others, wear the mask with particular attention especially in closed or crowded environments, cough or sneeze into the elbow or into a handkerchief, frequent hand hygiene, adequate ventilation in the closed environments. If possible, book the booster dose as soon as possible or, if you are not vaccinated, an appointment for the first dose.