Nationwide Effectiveness of First and Second SARS-CoV2 Booster Vaccines During the Delta and Omicron Pandemic Waves in Hungary (HUN-VE 2 Study).
Front Immunol
; 13: 905585, 2022.
Article
in English
| MEDLINE | ID: covidwho-1933690
ABSTRACT
Background:
In Hungary, the pandemic waves in late 2021 and early 2022 were dominated by the Delta and Omicron SARS-CoV-2 variants, respectively. Booster vaccines were offered with one or two doses for the vulnerable population during these periods. Methods andFindings:
The nationwide HUN-VE 2 study examined the effectiveness of primary immunization, single booster, and double booster vaccination in the prevention of Covid-19 related mortality during the Delta and Omicron waves, compared to an unvaccinated control population without prior SARS-CoV-2 infection during the same study periods. The risk of Covid-19 related death was 55% lower during the Omicron vs. Delta wave in the whole study population (n=9,569,648 and n=9,581,927, respectively; rate ratio [RR] 0.45, 95% confidence interval [CI] 0.44-0.48). During the Delta wave, the risk of Covid-19 related death was 74% lower in the primary immunized population (RR 0.26; 95% CI 0.25-0.28) and 96% lower in the booster immunized population (RR 0.04; 95% CI 0.04-0.05), vs. the unvaccinated control group. During the Omicron wave, the risk of Covid-19 related death was 40% lower in the primary immunized population (RR 0.60; 95% CI 0.55-0.65) and 82% lower in the booster immunized population (RR 0.18; 95% CI 0.16-0.2) vs. the unvaccinated control group. The double booster immunized population had a 93% lower risk of Covid-19 related death compared to those with only one booster dose (RR 0.07; 95% CI. 0.01-0.46). The benefit of the second booster was slightly more pronounced in older age groups.Conclusions:
The HUN-VE 2 study demonstrated the significantly lower risk of Covid-19 related mortality associated with the Omicron vs. Delta variant and confirmed the benefit of single and double booster vaccination against Covid-19 related death. Furthermore, the results showed the additional benefit of a second booster dose in terms of SARS-CoV-2 infection and Covid-19 related mortality.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Immunization, Secondary
/
COVID-19 Vaccines
/
COVID-19
Type of study:
Experimental Studies
/
Observational study
/
Prognostic study
/
Randomized controlled trials
Topics:
Vaccines
/
Variants
Limits:
Adolescent
/
Adult
/
Aged
/
Humans
/
Middle aged
/
Young adult
Country/Region as subject:
Europa
Language:
English
Journal:
Front Immunol
Year:
2022
Document Type:
Article
Affiliation country:
Fimmu.2022.905585
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