Omicron and reinfections, ISS: here’s who risks the most

With the Omicron variant, the risk of getting infected again, after having already had Covid, is higher among the under 50s, in women, among those who contracted the virus for the first time for over 7 months, among the unvaccinated or those immunized with one dose and between healthcare professionals. This is what emerges from the weekly report of the Higher Institute of Health (Iss) on the epidemiological surveillance of Covid-19 and vaccination efficacy, released today in the full version, which also shows that – from 24 August 2021 to 18 May 2022 – 489,414 cases of reinfection were reported, equal to 3.9% of the total number of cases notified. Percentage that in the last week was equal to 6%, stable compared to the previous week. Therefore, the analysis of the risk of reinfection shows that it is significantly higher: in subjects with the first diagnosis of Covid notified for over 210 days compared to those who had the first diagnosis of Covid-19 between the previous 90 and 210 days; between unvaccinated or vaccinated with at least one dose over 120 days versus vaccinated with at least one dose within 120 days; in females compared to males (phenomenon probably due to the greater presence of women in the school environment (more than 80%), where an intense screening activity is carried out and to the fact that women perform more often the role of caregiver in the family environment. And in the younger age groups (from 12 to 49 years) compared to people with the first diagnosis between the ages of 50-59 (probably attributable to higher risk behaviors and exposures, compared to the over 60 age groups), and among health workers more exposed than the rest of the population. THE CONTAGION – The effectiveness of the Covid vaccine booster, in the period of Omicron prevalence, in preventing infection is equal to 58% in subjects vaccinated with an additional dose / booster compared to unvaccinated. Percentage that stands at 44% within 90 days from the completion of the vaccination cycle, to 34% between 91 and 120 days and to 46% beyond 120 days from the completion of the vaccination cycle. The report also shows that those who have taken the booster have an 88% lower risk of becoming seriously ill than the unvaccinated, 70% in vaccinated with a full cycle of less than 90 days, 69% with a full cycle of 91 days. and 120 days, and 71% of those who have completed vaccination for more than 120 days.