Omicron variant and vaccine: symptoms, third dose

On November 26, the WHO designated variant B.1.1.529 as ‘Variant of Concern’ (Voc), with the variant name Omicron. Symptoms, vaccine efficacy and third dose, transmissibility: this is what we know about the variant isolated for the first time in samples collected in Botswana and South Africa. Read also There is consistent evidence that Omicron has a higher transmissibility than the Delta variant in countries, we read on the ISS (Higher Institute of Health) website. Severity of Infection Data on the clinical severity of patients infected with Omicron were collected week after week: early findings from South Africa, Great Britain and Denmark suggested a reduced 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 several countries is needed to understand how other indicators, such as oxygen use or mechanical ventilation or mortality, are associated with this variant in severe cases. The assessments relating to patient admissions, with a reduction in hospitalizations, must take into account the possible effect of immunity from previous infections or vaccines, beyond the less virulent characteristics that are associated with Omicron. 19, as the WHO recalled in recent days, can cause serious illness or death, particularly in the most vulnerable people by age or physical condition, and prevention through vaccination and non-pharmacological protective measures (distancing, hand hygiene , masks where required, remain critical. Vaccine Efficacy Results in Great Britain indicate a significant reduction in vaccine efficacy against symptomatic Omicron disease compared to Delta vaccine after two doses of Pfizer or AstraZeneca vaccine. greater efficacy against symptomatic disease two weeks after the booster, comparable or slightly lower to the one towards Delta. A study not yet peer-reviewed also reports a loss of efficacy in the primary cycle with respect to hospitalization, although to a lesser extent than with symptomatic disease.