Covid, Iss: booster 68% effective against Omicron, 91% on serious disease

The efficacy of the anti-Covid vaccine, in terms of percentage risk reduction, in the Omicron prevalence period (i.e. starting from January 3, 2022), is 68% in preventing the diagnosis of Sars-CoV-2 infection in who also did the booster dose. While it falls below 50% in those who have the two doses, up to 41% in those who have passed the 90th day from the completion of the vaccination cycle. This is one of the data that emerges from the latest update of the extended report of the Higher Institute of Health (ISS) with Covid surveillance data, the impact of infections and vaccination efficacy. As for the prevention of severe disease cases, an efficacy of 91% is reached in people with boosters. Among those who have taken two doses, the effectiveness varies from 73% which is observed for those vaccinated for less than 90 days, to 75% which is calculated both in those who are between 91 and 120 days from the completion of the vaccination cycle, and in those who has exceeded 120 days. OMICRON – Sars-CoV-2 can knock twice on the same person’s doors. With the Omicron variant it happens more often than in the past. And in the last week the percentage of reinfections on the total reported Covid cases is given equal to 3.5%. A figure, the one reported by the extended report of the Higher Institute of Health (Iss) on the trend of Covid-19, which is stable compared to the previous week. From 24 August 2021 to 30 March 2022, 299,837 cases of reinfection were reported, equal to to 3.1% of the total number of notified cases. Numbers that have grown over time. And from the analysis of the experts, starting from 6 December 2021, the date considered to be the reference for the start of the spread of Omicron, there is an increase in the adjusted relative risk of reinfection for those who had the first diagnosis for over 210 days compared to those who had it more recently; in unvaccinated or vaccinated with at least one dose over 120 days, compared to vaccinated with at least one dose within 120 days; in females compared to males; in the youngest, aged 12 to 49, and in health workers compared to the rest of the population. MORTALITY – “The age-standardized” Covid “mortality rate for the over 12 population in the period 4 February-6 March 2022 is about 14 times higher for the unvaccinated than for those who did the booster (51 deaths per 100,000 inhabitants, compared to 4 / 100,000). 6 times higher than vaccinated with additional dose / booster (140 hospitalizations per 100,000 inhabitants against 22 / 100,000). The rate of hospitalization in intensive care in the same period is instead about 9 times higher for the unvaccinated than records in whom did the booster (9 admissions to intensive care per 100,000 inhabitants against 1 / 100,000).