Study on effectiveness of vaccination against SARS-CoV-2 in Uruguay in 2021: preliminary results
Uruguay's Ministry of Public Health is conducting a study on the effectiveness and safety of a SARS-CoV-2 vaccine, led by an interdisciplinary team. Its objective is to monitor the effectiveness of vaccination against SARS-CoV-2 in preventing infection, severe disease, and mortality from SARS-CoV-2. As of 1 June of this year, in Uruguay, 51.8% of the population had been vaccinated with at least one dose of COVID-19 vaccine, and 29.2% of the total population had received both doses according to the defined schedule.
Preliminary results from this study indicate that there was a 66.0% reduction in COVID-19 cases among health care workers at 14 days following the last dose of the CoronaVac vaccine, and a
78.2% reduction at the same point for the Pfizer vaccine. In the general population, there was a 64.5% reduction in COVID-19 cases for people between the ages of 18 and 49 who received the CoronaVac vaccine, and a 61.5% reduction in people ages 50 to 69 who received the same vaccine. The reduction in COVID-19 cases for the group that received the Pfizer vaccine was 79.7% in people ages 80 and older. The reduction in intensive-care hospitalizations (ICH) for COVID-19 was 94.9% for people ages 18 to 49 and 92.2% for people ages 50 to 69 who received the CoronaVac vaccine, and a reduction of 96.7 in ICH for COVID-19 in people ages
80 and older who received the Pfizer vaccine. In terms of mortality from COVID-19, there was a 95.3% reduction in deaths among people ages 18 to 49 who received the CoronaVac vaccine, and a reduction of 95.2% in those ages 50 to 69 who received the same vaccine. In the case of the Pfizer vaccine, there was a 94% reduction in deaths among people ages 80 and older.
These figures are preliminary, and are not from a peer-reviewed publication; they should therefore be interpreted with caution. The research team is developing multivariate statistical analyses to incorporate information on demographics and at-risk groups.