COVID-19 vaccination and non-pharmaceutical interventions in selected European settings: a systematic review

Background COVID-19 pandemic responses in European countries relied on both vaccination campaigns and non-pharmaceutical interventions (NPIs). While vaccination reduced severe disease, NPIs remained necessary to limit transmission, particularly during periods of variant emergence. However, the effectiveness of these strategies depended on social trust, communication clarity, and behavioural adaptation. Objective To synthesize empirical evidence on shared determinants of vaccination and NPI-related behaviours, behavioural relationships between these strategies, and evidence concerning their joint epidemiological effects. Methods PubMed and Scopus were searched on 11 February 2025 using free-text terms for COVID-19, vaccination, and social or non-pharmaceutical measures. Eligible studies were peer-reviewed, empirical (quantitative, qualitative, or mixed-methods), conducted by authors affiliated with selected European institutions, and examined relationships between vaccination and NPIs. Studies based solely on modelling or secondary data were excluded. Data were synthesized narratively due to heterogeneity of study designs and outcomes. Results Twelve studies met inclusion criteria. Trust in scientific and governmental authorities consistently predicted adherence to NPIs and willingness to vaccinate. Sweden's reliance on voluntary measures was effective where institutional trust was high. In contrast, inconsistent communication in the United Kingdom contributed to reduced adherence and public frustration. Vaccinated individuals tended to increase social contacts, an association compatible with behavioural adaptation. A conjoint experiment examined stated vaccination preferences in relation to NPI attributes. Younger populations experienced notable psychological strain during prolonged restrictions. Conclusions The synthesis primarily informs social and behavioural relationships involving vaccination and NPIs. Shared determinants and behavioural associations should not be interpreted as evidence of synergistic effects on infection, hospitalisation, or mortality. Future pandemic preparedness should prioritize trust-building, consistent messaging, and targeted psychosocial support for vulnerable groups.