The impact of four dominating variants and vaccine coverage on Covid-19 mortality: the Malta case

Background Disease burden can be quantified by mortality. The European Islands of Malta experienced a seesaw of Covid-19 surges in mortality and cases across the pandemic. The study aims to assess the impact of Covid-19 mortality across the four phases dominated by different variants while considering the vaccination coverage among the Malta population. Methods Covid-19 epidemiological data was obtained up till end of February 2022 from the websites of the Malta Ministry of Health and the European Centre for Disease Prevention and Control. Data was categorised into the four periods according to reported dominant Covid-19 variant. The Years of life lost (YLL) and Case-Fatality-Ratio (CFR) for each period were estimated. Correlations were performed between mortality and vaccinated age-groups. Results The original Covid-19 period (54 weeks) had the highest YLL (6633.53), followed by the Omicron variant period (12 weeks; 2,692.17). The Alpha variant period (7 weeks) had the highest CFR (1.89) followed by the Original Covid-19 (1.37). A significant negative correlation was present between two dose vaccination and the 60-69 years (p = 0.01), 70-79 years (p =