Objective COVID-19 spread globally, including across Europe, resulting in different morbidity and mortality outcomes. The aim of this study was to explore the progression of the COVID-19 pandemic over 18 months in relation to the effect of COVID-19 vaccination at a population level across 35 nations in Europe, while evaluating the data for cross-border epidemiological trends to identify any pertinent lessons that can be implemented in the future. Methods Epidemiological data was obtained from European Centre for Disease Prevention and Control and Our World in Data databases while Ministry of Health websites of each respective country and local newspapers were utilized for COVID-19-related vaccination strategies. Case, mortality, and vaccination incidence comparative analyses were made across neighbouring countries. Results Similar morbidity and mortality outcomes were evident across neighbouring countries over 18 months, with a bidirectional relationship evident between cumulative fully vaccinated population and case fatality rates. Conclusion Countries’ COVID-19 outcome is related on national mitigative measures, vaccination rollouts, and neighbouring countries’ actions and COVID-19 situations. Mass population vaccination appeared to be effective in reducing COVID-19 case severity and mortality rates. Vaccination equity and pan-European commitment for cross-border governance appear to be the way forward to ensure populations’ return to “normality”.