Each and every one of the vaccines against Covid-19 that are currently being inoculated have demonstrated their safety and efficacy in preventing severe disease and, therefore, contribute significantly to reducing the risk of hospital admission, ICU and death from Covid-19. A benefit that has not only been demonstrated in clinical trials involving tens of thousands of volunteers around the world, but has also been reinforced in real life with the advancement of mass vaccination campaigns.
In this context, the scientific evidence in this regard is growing and we focus on a recent study conducted in Canada, the results of which have been published in pre-print on the medRix server . It is currently awaiting peer review.
To carry out the study, the data collected in the Covid-19 Case and Contact Management System of Ontario (Canada) has been used. These were integrated into COVaxON, a data set on vaccination against Covid-19 in the country with the aim of being able to match study subjects and make comparisons. The main goal of this work was to determine the impact of vaccination against SARS-CoV-2 in reducing ICU admissions and deaths from Covid-19 in people vaccinated and hospitalized for Covid-19., compared with people hospitalized for the disease but who had not been vaccinated. In total, the data of 20,064 people hospitalized with Covid-19 between January 1, 2021 and January 5, 2022 have been analyzed.
Among the 3,353 subjects vaccinated against Covid-19, 51.12% had received one dose, 44.23% two doses and 4.65% the complete regimen plus a booster. Compared with those who had not received any dose, they reported a lower risk of needing admission to the ICU and death from Covid-19.
The authors of the research state that the number of vaccine doses inoculated has shown an inverse dose-response association in relation to admission to the ICU and deaths related to Covid-19 among vaccinated subjects. It should be noted that, although significant protection has been observed among those vaccinated against the Delta variant (B.1.617.2, originally detected in India), it is reduced in cases where the infection is caused by the currently dominant variant at global level, Omicron (B.1.1.529, originally detected in South Africa).
One conclusion that should be emphasized is the fact that vaccines against Covid-19 seem to be more effective in reducing the chances of admission to the ICU . This efficacy is slightly reduced if we talk about mortality.
Those responsible for this study emphasize the fundamental role of vaccination in preventing hospitalizations and deaths from Covid-19, although serums failed to prevent the serious infection that caused hospitalization in some cases. Despite this nuance, vaccines continue to be our best ally when it comes to reducing the risk of hospital admission and death as a result of the disease.
“We identified a decreased risk of ICU admission and death in vaccinated individuals compared with time-matched, unvaccinated controls, even when vaccines failed to prevent infection severe enough to cause hospitalization. Even with the declining efficacy of vaccines against infection by new variants , vaccines remain an important tool in reducing ICU admission and mortality,» the authors conclude.