Since the World Health Organization (WHO) declared COVID-19 a global pandemic in March 2020 (1), coordinated efforts to limit viral transmission and mitigate strain on public health systems have been implemented worldwide (2). Preventive measures, including lockdowns, social distancing, hand hygiene, and mask usage, were widely recognized as effective strategies to reduce transmission (3). Concurrently, the rapid development and deployment of COVID-19 vaccines played a critical role in pandemic control (4).

Airborne transmission risk is modulated by factors such as ventilation quality (5), exposure duration (6), and adherence to preventive measures (7–9). These interventions not only curtailed COVID-19 spread but also reduced the incidence of other airborne diseases, such as seasonal influenza (10, 11). However, long-term adherence to measures like physical distancing has proven challenging due to socio-economic and behavioral barriers (12, 13). Lockdowns and travel restrictions further strained global economies and supply chains (14), underscoring the need for sustainable strategies.

Successful immunization campaigns enabled a gradual return to normalcy (15–17), yet maintaining preventive behaviors remains critical to minimize pathogen transmission and bolster pandemic preparedness (18).

Risk perception—defined as the intuitive assessment of potential hazards—shapes health-related decision-making (19, 20). This cognitive process involves two components: (1) estimating the probability of harm and (2) subjectively evaluating its severity (21). Differently, risk preferences reflect stable tendencies toward risk avoidance or acceptance (22). Both constructs influence health behaviors, including vaccination uptake and adherence to preventive measures (23).

The introduction of COVID-19 vaccines raised questions about their impact on risk perception and behavioral adherence. Vaccinated individuals may exhibit risk compensation; wherein reduced threat perception diminishes protective behaviors (24). While evidence suggests vaccination lowers self-perceived risk and compliance (24), individuals with heightened public health awareness often sustain preventive practices, particularly in high-risk settings (25, 26). Motivation, mediated by risk perception, remains a key predictor of adherence (27), though messaging and individual awareness also play roles (28).

As the success of current and future public health campaigns on reducing the impact of COVID-19 and other infectious diseases dwell on the possibility to improve both vaccination uptake and adherence to non-pharmaceutical intervention. While the implementation of these measures, during the pandemic, was common and widely accepted, the post-pandemic transition has seen a significant drop in both vaccination and adherence to preventive measures (29). However, understanding the dynamic of retaining preventive measures, not only for the purpose of containing the impact of pandemic, but also for the effect on other air-borne transmitted infection is pivotal to prevent their diffusion. Therefore, this systematic review and meta-analysis aim to assess the impact of COVID-19 vaccination on risk perception change as a predictor of sustained preventive behaviors during the COVID-19 pandemic.

This systematic review and meta-analysis examined the association between COVID-19 vaccination and risk perception change as a predictor of sustained preventive behaviors during the COVID-19 pandemic. The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (30).

Risk perception and adherence to protective behaviors are pivotal to pandemic management, modulating viral transmission and the efficacy of containment strategies. While COVID-19 vaccination reduced disease severity and transmission, its impact on risk perception and behavioral adherence exhibited marked heterogeneity. Overall, adherence levels remained similar between vaccinated and unvaccinated individuals, with meta-analyses confirming negligible differences and low variance across groups. While some vaccinated individuals sustained protective measures despite static risk perception, others engaged in risk compensation, perceiving vaccination as sufficient protection. These dynamics underscore the need for nuanced public health messaging to promote sustained behavioral adherence.

The 10 studies analyzed—spanning diverse regions, including the USA, China, Belgium, and 16 European nations—reflect varied cultural, social, and political contexts shaping health behaviors. This geographical diversity strengthens generalizability, though it introduces variability in risk perception metrics and behavioral norms.

A significant proportion of vaccinated individuals, maintained precautions post-vaccination, likely driven by persistent awareness of residual risks or social responsibility (33, 34). However, declines in handwashing (−15%) and distancing (−22%) alongside increased public transport use (+18%) (35) suggest risk compensation behaviors (42), wherein perceived vaccine-derived security reduced vigilance. This aligns with evidence that COVID-19 vaccination lowers self-perceived risk and adherence (42–44) underscoring the need to address behavioral complacency in public health campaigns.

Notably, boosted individuals exhibited higher adherence and risk perception than partially/unvaccinated counterparts (41), potentially reflecting heightened awareness of waning immunity. Conversely, unvaccinated individuals intending to vaccinate reported elevated risk perception compared to vaccine refusers (23), suggesting fear of infection and vaccine confidence synergistically drive uptake (45–47).

The meta-analysis revealed no significant difference in risk perception between vaccinated (70.3, 95% CI 60.8–79.8) and unvaccinated subgroups (70.8, 95% CI 61.9–79.6; β = −0.5%, p = 0.87). This null finding may reflect risk compensation: vaccinated individuals, despite inherently higher baseline risk perception (38, 39), may offset perceived protection via reduced behavioral adherence, attenuating measurable differences between groups. Such compensation is well-documented in health psychology, wherein interventions reducing perceived risk inadvertently disincentivize precautionary behaviors (42–44).

Understanding the interplay between COVID-19 vaccination status, risk perception, and protective behaviors is critical for designing adaptive public health strategies. While vaccination campaigns have been pivotal in curtailing disease severity and transmission, their influence on behavioral adherence—marked by risk compensation in some subgroups—demands nuanced policy approaches.

To sustain precautionary measures, initiatives should leverage messaging that: (1) underscores communal responsibility through narratives emphasizing protection of vulnerable populations, as shown in studies linking higher perceived collective risk with greater adherence (48); (2) highlights the persistence of viral evolution, including risks of breakthrough infections and asymptomatic transmission consistent with evidence indicating that awareness of residual risk predicts sustained protective behaviors (49); and (3) addresses risk compensation by reframing vaccination as complementary to—not substitutive for—preventive behaviors. Tailored, culturally resonant communication, disseminated via trusted community leaders and digital platforms, can mitigate complacency while fostering equitable adherence (50).

Integrating these evidence-based insights into policy frameworks will optimize population-level vaccine efficacy and resilience against future pandemics, ensuring public health strategies evolve in tandem with behavioral and epidemiological realities.

This study offers several strengths. First, it systematically examines the interplay between COVID-19 vaccination status, risk perception, and adherence to preventive behaviors across diverse populations and geographic contexts, enhancing ecological validity. By including both vaccinated and unvaccinated subgroups, it enables nuanced comparisons of behavioral patterns. Adherence to PRISMA guidelines and the integration of meta-analytic methods further bolster methodological rigor, providing a robust quantitative synthesis of global evidence.

However, limitations must be acknowledged. First, the relatively small number of included studies (n = 10, of which six were included in the meta-analysis) constrains the external validity of our findings. This limited evidence base may reduce the generalizability of results across different populations, settings, and time periods. To mitigate this, we performed a comprehensive search across multiple databases and applied a rigorous screening process, ensuring that all eligible studies were captured. Further high-quality studies are therefore needed to validate and extend these findings in broader and more diverse cohorts. Second, while the low heterogeneity (I² = 17.5%) supports internal consistency, the exclusion of studies with divergent methodologies—though necessary to ensure analytical coherence—may have omitted contextually relevant insights. Nonetheless, sensitivity analyses confirmed that the overall conclusions remained stable despite these exclusions. Third, variations in study design and data collection methods (e.g., self-reported behaviors, cross-sectional frameworks) may have introduced bias, limiting causal inference. To reduce this impact, we carefully assessed study quality and applied consistent inclusion criteria, thereby increasing comparability across studies. Fourth, the predominance of cross-sectional designs precludes longitudinal assessment of risk perception dynamics. Although this limits the ability to infer causality or long-term trends, the convergence of findings across independent studies strengthens confidence in the overall conclusions. Future research should adopt time-series or cohort approaches to expand on these results. Fifth, this review was not prospectively registered in PROSPERO, which may reduce transparency and increase the risk of selective reporting. However, we strictly followed PRISMA guidelines to ensure methodological rigor and transparency, and a complete description of the methodology is provided in the Supplementary material. Finally, restricting the search to English-language studies may have introduced selection bias. This choice, however, is common practice in systematic reviews, as the majority of international scientific literature is conventionally published in English. Moreover, accurate interpretation of findings in multiple foreign languages would have required expertise beyond the scope of the review team. By focusing on English-language studies, we minimized the risk of misinterpretation or inconsistent data extraction, ultimately strengthening the reliability of the synthesis.

The relationship between COVID-19 vaccination, risk perception, and protective behaviors is shaped by cognitive evaluations, affective responses, and socio-contextual factors. While COVID-19 incidence has markedly declined and preventive measures are no longer widely practiced in many contexts, our findings remain relevant by illustrating how vaccination can interact with risk perception and behavioral adherence. The meta-analytic null finding—no significant difference in risk perception between vaccinated and unvaccinated subgroups—suggests that baseline perceptual differences may be offset by behavioral adjustments post-vaccination.

These insights underscore the necessity of public health strategies that go beyond one-size-fits-all messaging. In future pandemic scenarios or vaccination campaigns for respiratory infections such as influenza or RSV, emphasizing communal responsibility, residual transmission risks, and the complementary role of vaccination and preventive behaviors may mitigate complacency. Moreover, integrating psychological, behavioral, and epidemiological evidence can inform preparedness frameworks and support the design of behaviorally informed interventions. By applying these lessons across infectious threats, policymakers can strengthen resilience, ensure adaptive health strategies, and sustain population-level protection even as epidemiological conditions evolve.