The study was carried out by the Health Surveillance Directorate, which constantly evaluates the effectiveness of vaccines against COVID-19, following the methodology proposed within the framework of the Network for the Evaluation of Vaccine Effectiveness in Latin America. and the Caribbean – influenza and COVID-19 (REVELAC) of the Pan American Health Organization (PAHO).
This report presents the results obtained from the evaluation of the effectiveness of vaccines against COVID-19 in Paraguay, using the sentinel surveillance network for severe acute respiratory infections (SARI). The results presented in this report come from the data provided by this network for the period May 2021 – April 2022.
A total of 4,512 SARI patients were admitted to four sentinel centers that participated in the evaluation. Two of them from the metropolitan area of Asunción and two from Alto Paraná. Of these, 2,458 (54.5%) were positive for SARS-CoV-2 (cases) and 2,054 (45.5%) were negative for SARS-CoV-2 (controls).
Most of the cases were hospitalized during the months of highest incidence (between May and July 2021), while most of the controls (hospitalized for non-COVID-19 pneumonia) were hospitalized from August, when the incidence of COVID -19 decreased. As of the end of 2021, an increase in cases due to the Omicron variant is observed, which reached the peak of incidence in epidemiological week 3 of 2022.
Preliminarily, the effectiveness of the vaccines against hospitalization for COVID-19 has been estimated in the aggregate for all the vaccines. Adjusted effectiveness estimates are shown for the circulation periods of the Gamma, Delta and Omicron variants, respectively.
According to the study, for the period of predominant circulation of the Gamma variant (May 1 to August 7, 2021), an effectiveness of 42% was registered with all the vaccines, when the vaccination was partial. An effectiveness of 56.3% with all vaccines, in complete vaccination (primary schedule of two doses).
For the predominant circulation period of the Delta variant (from August 22 to December 18, 2021), it was observed that the effectiveness in reducing hospitalizations was between 69.4% and 80.3% depending on the completeness of the primary scheme.
For the period of predominant circulation of the Omicron variant (from January 2 to April 2, 2022), an effectiveness of 30.4% was observed globally, without a booster dose, an effectiveness of 72.4% with all the vaccines plus the booster dose.
In this period it was observed that if the vaccine is recent (less than 90 between contagion and last dose), the effectiveness to reduce hospitalization reaches 78.8%.
The results obtained in this analysis indicate:
– High effectiveness of vaccines against hospitalization in Gamma and Delta periods.
– Effectiveness decreases in the Omicron period, although it is maintained if the vaccination is recent.
– The booster dose increases the effectiveness of the vaccines against Omicron.
– Importance of the third dose to maintain high effectiveness.
See the full note at the following link: https://dgvs.mspbs.gov.py/page/#1789
The entrance Booster anticovid vaccines increase protection against the disease was first published in diary TODAY.
