Countries across the world have experienced a tough period triggered by COVID-19 since the end of 2019, including medical system collapse, millions of deaths, financial crises, and impacts on daily life for billions of people (1, 2). We noticed that different strategies were adopted by different countries; however, vaccination was a common policy promoted by most countries (3, 4). Vaccination is regarded as an effective way to contain the spread of COVID-19, though the effectiveness against the new variants has declined according to current studies (5, 6).

Current studies have widely discussed COVID-19 vaccine hesitancy, covering disparities over age, occupation, and gender, and vaccine motivation as well (7–9). Most of the current motivation studies regarding the COVID-19 vaccine have examined the protection motivation theory or self-determination theory using path analyses or multiple regressions over different countries and populations (10–13). These studies have explored the key motivations of self and family member protection, trust of vaccine safety and efficacy, promoting/modeling vaccination, doing one's duty, being a helper, and ending the pandemic/restoring normalcy (14–16). Furthermore, key motivations of vaccine uptake were summarized into differentiated patterns, for instance, the pattern of infection-related risk perception, pandemic-related health concerns and vaccine-related safe protection (17, 18). However, region and culture factors have been scarcely touched.

We believe that there might be disparities in different culture contexts when considering vaccine motivation. For examples, China has long been deeply influenced by the Confucian culture. Chaxugeju, also called the differential mode of association, was proposed by Fei to reveal the interpersonal pattern of close and distant relationships (19). Unlike clearly defined social boundaries in western societies, the Chinese traditional society is “just like the circles that appear on the surface of a lake when a rock is thrown into it. Everyone stands at the center of the circles produced by his or her own” (20). Chaxugeju describes a relationship from me to close family members or relatives, and to more distant others, which is gradually transmitted from the near to the far, reflecting the very traditional Chinese interpersonal relationship, and also builds the basic traditional social structure. The differential pattern is also reflected in people's behavior patterns, including vaccination behavior, which is a significant cultural factor that cannot be ignored. Some studies have pointed out that the Chaxu culture has been gradually disintegrating with urbanization, and others have argued that the differential culture still has a profound impact on Chinese society, especially for rural-to-urban migrants (21). Urbanization changes are accompanied by some notable features, such as class differentiation related to socioeconomic factors, regional disparities of urban-rural and west-east, and migrants' social roles, all of which have not been considered in the existing motivation studies in vaccination. Thus, we paid special attention of SES, migration, and region factors in the context of Chaxu culture in this vaccine motivation study. The extent to which their relation with vaccine motivation is identical, is unclear. We assumed that SES, migration and region may not represent the same causal processes, so we studied the relations between education, income, occupation, migration, and region (seen as five distinct social dimensions) and COVID-19 vaccination motivation pattern.

Metropolis were hardest hit by waves of COVID-19, with high population density and massive population movement. Thus, we paid special attention in vaccination motivation patterns in metropolitan areas in China, examining whether citizens' motivation follows the traditional Chaxu culture, in which region, SES, and migration were considered as significant factors.

Interestingly, three motivation patterns of COVID-19 vaccination were found based on the LCA model that were named Self-protection, Trust and Self-protection, and Trust and Differential Protection. Consistent with the current studies, protection and trust were the primary components of vaccination motivation (25). In the context of China, we observed that the Trust and Differential Protection Pattern followed the traditional Chaxu cultural attitudes, with an apparent self-family-community protection circle in which reflecting a traditional me-to-others relationship. In addition, Self-protection Motivation Patterns with or even without trust were also identified, and the latter was self-protection motivated. However, a lack of basic trust in vaccine safety and efficacy seemed to be a self-contradictory state. We concluded that this could have been due to the initial stage of vaccination promotion that caused a lack of trust, and such concerns were also found in the research conducted in other settings (23). Such a distinctive phenomenon found in the metropolitan areas of China was surprisingly consistent with the western sociology theory, i.e., the social capital theory, which is a broad theoretical construct that explains the social resource sharing mechanism with some combination of distinct yet related contextual dimensions of trust, social networks, and norms of reciprocity (28). In the setting of vaccine motivation in China, protection is a situational expression of a reciprocal norm based on social networks.

We found that the Chaxu motivation pattern was not the predominant one in the metropolitan areas in China that might be disintegrated by rapid urbanization and class differentiation. Models showed that populations with higher income or non-manual labor occupations had higher probabilities distributed in Self-protection or Trust and Self-protection, rather than a self-family-community protection pattern. The traditional society relies on close social network relations to operate, but studies have shown that urbanization can disrupt existing social structures and exacerbate social stratification, and this dilutes connections between people (29). For example, traditional society is often confined to small communities, and people are familiar with each other. However, in the modern society, people are alienated and isolated from the community they live in. Higher-class groups are less dependent on traditional social network relationships, Chaxugeju, but tend to have a Self-protection Pattern. However, education, one of the SES measurements, worked on the motivation pattern in the opposite way. Survey participants with higher education levels tended to get vaccinated for the trust and differential-protection pattern. Current studies have demonstrated that education can help improve social trust (30); however, diversity of social capital can erode social trust and participation, and the latter was a prominent line of scholarship globally that linked ethno-racial diversity to undesirable collective outcomes, most notably, low levels of trust, civic engagement, and social capital (31). A causal conclusion could not be made in this study, but we obtained a preliminary outline where education, income, and occupation were all SES measurement variables, but the latter two, as important measurement variables of social capital, played a negative role in social trust, while the former played a positive role. Based on the fundamental disparities, the three had diametrically opposite roles in the motivation mechanism.

However, the Chaxu culture was also preserved in vaccine motivation to some degree. Compared with the Self-protection motivation pattern, migrants tended to follow a differential and trust pattern. Migrants are products of rapid urbanization in China. Chinese internal migration is a unique event in human history and may well be one of the greatest migration events ever to have taken place (32). Economic reforms since 1978 have brought about an unprecedented surge in China's migrant population. According to the National Bureau of Statistics, the size of the migrant population was 380 million in 2020, accounting for over 26.9% of the national total population (33). The majority of migrants are rural-urban individuals who have worked and lived in cities for years but are still officially registered as residents in their rural places of origin and are thus viewed as a “floating population.” (34). Although the huge migrant population used to provide cheap and flexible labor forces that have fostered industrialization and urbanization in China's post-reform development, their floating or unstable status in the spatial and social senses has been increasingly regarded as unsustainable in the future (35). Current studies have demonstrated that migrants rely more on social networks compared with local residents to integrate into new living environments or seek non-agriculture jobs (offering information, providing financial aid, or recommending a job) (36). Similarly, our study also revealed that participants from Shenzhen, rather than Shanghai, also tended to have the trust and differential pattern for vaccination. With more rural-urban migrants in Shenzhen, more traditional culture was observed in Shenzhen. It seems that Shenzhen was more influenced by Chaxugeju than Shanghai. A social network study in Shenzhen found that after migration, migrants rebuild their social networks along with changes in their occupations and surroundings (37). Thus, it is not surprising that the self-centered social network circle was also captured in the vaccination motivation in the group of migrants and in Shenzhen as well.

Our study also showed that motivation patterns varied by gender that acted as a moderator in the motivation pattern. Gender differences in motivation were widely discussed, covering education, occupation, migration, and healthcare service utilization. Specifically, in this study, females with higher income were likely to get vaccinated for Self-protection, and those with higher education levels were prone to differential protection when obtaining the vaccination, however, such trends were not found in male groups. Compared with males, females donate more money to charities and volunteer in greater numbers; men and women differ in their motivations for volunteering. Education was shown to be positively correlated with female participation (38, 39). Thus, females with higher education levels behaved in a more traditional way, with self-family-community protection and a different internal function mechanism.

Vaccination promotion is a worldwide campaign to fight against mutated viruses of COVID-19, and we observed the efforts made by health departments of countries across the world. Based on our research findings, we propose that cultural factors should be considered when continually advancing vaccination efforts. People in metropolitan areas of China have subverted the previous self-centered circle theory and are more concerned about the safety and effectiveness of vaccines and the safety of individuals. In other context, similar vaccine motivation was found that the most commonly reported reasons to get vaccinated were to protect self, family and others (40). Even so, in countries with contexts and cultures different from that in China, we believe more culture context should be taken into consideration. Heidi Larson, whose recent book, Stuck, summarized her decades of research on vaccine hesitancy, pointed out that vaccine reluctance and refusal are not issues that can be addressed by delivering more or better information, but issues involving broader social factors including history, region, and beliefs (41). We believe that vaccine trust is the primary condition for vaccination, and on this basis, different patterns of behavioral motivation differences are derived. These patterns included protection of individuals and families, empathy, and the restoration of regional social order, all of which should be seriously considered by local authorities, as Larson proposed, before you attempt to persuade, try to understand.

This study still has some limitations. First, although it was a multi-center study, comparisons between urban and rural areas are lacking. There are significant disparities in China, including economic development, social structures, and cultural customs. It is worth comparing vaccine motivation patterns in urban and rural China in further research. Second, a longitudinal analysis is necessary to track the changes in motivation over time.

The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding author.

The studies involving human participants were reviewed and approved by Fengxian District Central Hospital Medical Ethic Committee. The patients/participants provided their written informed consent to participate in this study.

JH and YL designed and conceived the study, were in charge of acquisition, analysis, or interpretation of data, and drafted the manuscript. YL and JG were responsible for data integrity and data analysis accuracy. ZJ conducted critical revisions of the important intellectual content. JG and JH performed the analyses and reviewed the data. JH obtained funding. YYang, YYan, YB, and XG provided administrative, technical, and material support. YL provided supervision. All authors reviewed and approved final version of the manuscript.