Assessing the impact of the four COVID-19 variants and the vaccine coverage on mortality in Malta over 2 years: An observational case study

Abstract

BackgroundMortality may quantify a population's disease burden. Malta, like other European countries, experienced COVID-19 surges in cases and mortality across the pandemic. This study assesses COVID-19's mortality impact, while exploring the effects of the four dominant COVID-19 variants and that of the vaccination coverage on the Maltese population.MethodsCOVID-19 data (cases, mortality, positivity, and vaccination rates) was obtained from the websites of the European Center for Disease Prevention and Control and the Malta Ministry of Health. Data was categorized into the four periods according to reported dominant COVID-19 variant. Years of life lost (YLL) and Case-Fatality-Ratio (CFR) for each period were estimated. CFR was also estimated for the pre-vaccine and post-vaccine periods.ResultsThe original COVID-19 period (36 weeks) had the highest YLL (4,484), followed by the Omicron variant period (12 weeks; 1,398). The Alpha variant period (7 weeks) had the highest CFR (1.89%) followed by the Original COVID-19 (1.35%). The pre-vaccine (1.59%) period had higher CFR than the post-vaccine period (0.67%).ConclusionVarious factors contributed to mortality, but the variant's infectivity, transmissibility, and the effectiveness of the vaccine against the variant play an important role. Reducing mortality by embracing mass vaccination that targets current variants along with other non-pharmaceutical interventions remains paramount.

Evolutionary and spatiotemporal analyses reveal multiple introductions and cryptic transmission of SARS-CoV-2 VOC/VOI in Malta

“…Prompted by an escalation in the daily number of positive cases in summer 2020, 671 SARS-CoV-2 samples collected between August 2020 and January 2022 were sequenced by the Molecular Diagnostics-Infectious Diseases at the Mater Dei Hospital to identify and trace circulating variants. In this study, we analyzed the viral sequences generated in this study in addition to all SARS-CoV-2 genomes from Malta available at the Global Initiative on Sharing All Influenza Data database (GISAID; https://www.gisaid.org ) ( 18 , 19 ) and leveraged a comprehensive approach involving epidemiological and viral genomic data to reconstruct the timelines of viral introductions, their geographic origins, and the contribution of detected introductions to the epidemic evolution of SARS-CoV-2 in Malta ( 20 ).…”