The European Center for Disease Prevention and Control (ECDC) has updated the vaccine effectiveness results against SARS-CoV-2 and has determined that the vaccine has had an interval 93 percent confidence interval (CI) between hospitalized patients with infection severe respiratory tract, observed 14 days after complete vaccination with the primary series.
This document reports the pooled estimates from the ECDC study on the efficacy of the covid vaccine, conducted by implementing a multinational approach using the “Basic Protocol for ECDC Studies on the Efficacy of the Covid-19 Vaccine”. COVID-19 vaccine against hospitalization with laboratory-confirmed severe acute respiratory infection with SARS-CoV-2, version 1.0″.
This second update contains vaccine effectiveness results among people aged 30 years and older, for the pre-Delta and Delta-dominant periods (January 3 to May 31, 2021 and July 1 to December 15, 2021, respectively). ). It also contains estimates by COVID-19 vaccine product (ie Comirnaty (Pfizer/BioNTech) and Vaxzevria (AstraZeneca)).
Which covid vaccine is more effective?
For the Pfizer/BioNTech vaccines (Comirnaty), the effectiveness of the vaccine has been 94 percent in the pre-Delta period and 82 percent in the Delta period.
The results of the analysis by age group, for all vaccine products combined and during the pre-Delta period, showed that the vaccine effectiveness adjusted for partial vaccination was greater in those aged 65 to 79 years than in the other age groups, although all confidence intervals overlap.
For the Delta period, the adjusted vaccine effectiveness for full vaccination with the primary series has been higher in the younger age groups than in the older age groups: 55 percent (95% CI: 25-74) in those over 80 years old compared to 91 percent (95% CI: 81-95) in people aged 30-49 years (for all products combined, although the results for Comirnaty were very similar).
The adjusted vaccine effectiveness for Vaxzevria (AstraZeneca) observed, around 14 days after complete vaccination with the primary series, it was 79 percent (95% CI: 60-89%) in people 50 to 64 years old and 87 percent (95% CI: 73-94%) in people 65 to 79 years old.
How does the study was realized?
A total of 11 EU countries have participated in the multicenter study (Belgium, Croatia, Czech Republic, France, Greece, Ireland, Luxembourg, Malta, the Netherlands, Portugal, Spain). Most people enrolled in the study received the Comirnaty (Pfizer/BioNTech) COVID-19 mRNA vaccine.
Specifically, it has been confirmed that the adjusted effectiveness of the SARS-CoV-2 vaccine, according to the laboratories, among hospitalized patients with severe respiratory infection observed 14 days after complete vaccination with the primary series of any product of vaccine has been 93 percent.