Covid, third dose ineffective or risky in young people? Iss: “False”

It is false that the third dose of the Covid vaccine “in the 12-39 age group induces a loss of protection compared to those who have only taken two doses”. And it is false that “the booster could even put the immune system at risk in younger people” because “at the moment there is no evidence that the booster negatively affects the immune response”. “Clinical trials and real world studies conducted in other countries have shown greater protection from the additional dose in all age groups.” The Higher Institute of Health (Iss) underlines this in a note published on its website. The latest ISS reports show “that the risk of hospitalization in the 11-39 age group is very similar, and sometimes slightly higher, in those who have taken the booster than in those who have only two doses of the vaccine even if for more than 120 days. . However, this does not mean that the booster is not very effective or even counterproductive – he remarks – because it is necessary to consider several factors that can lead to an underestimation of the effectiveness in subjects who received the booster dose in this age group “. in consideration of the bulletins, the last for which consolidated data is available, is the one that includes hospitalizations ranging from the end of December to the end of January. “The subjects in the 12-39 years age group considered in this period are therefore those who first completed the vaccination cycle with the booster dose. These subjects – continues the ISS – have an intrinsic risk of infection / hospitalization / death. compared to the rest of the population and are those who have had priority access to vaccination precisely because they are considered at high risk immunocompromised, transplanted, health workers). Frailty is a confounding factor in this analysis, given that fragile cases (immunosuppressed, with different comorbidities, etc.) have at the same time a greater probability of having received the booster and a greater probability of being hospitalized (and of death) “. “Considering that at the end of December only 8% of subjects in the age group 12-39 had received the booster dose, the estimate of vaccine efficacy after the booster dose, during this period, suffers from a clear selection bias. As subsequent periods are examined, the efficacy estimates referring to this population will be less affected by this confounding factor “, observes the ISS. In the period under consideration, it should also be considered “that the context was rapidly evolving and various factors may have contributed to an underestimation of vaccine efficacy after the booster dose: the main one is the advent of the Omicron variant with its greater infectivity, which led to a sudden increase in the overall incidence with the consequent increase in diagnoses among people who were admitted to hospital for other pathologies “.