Global Experiences of Community Responses to COVID-19: A Systematic Literature Review

Objective This study aimed to conduct a systematic review of the global experiences of community responses to the COVID-19 epidemic. Method Five electronic databases (PubMed, Embase, CINAHL, ScienceDirect, and Web of Science) were searched for peer-reviewed articles published in English, from inception to October 10, 2021. Two reviewers independently reviewed titles, abstracts, and full texts. A systematic review (with a scientific strategy for literature search and selection in the electronic databases applied to data collection) was used to investigate the experiences of community responses to the COVID-19 pandemic. Results This review reported that community responses to COVID-19 consisted mainly of five ways. On the one hand, community-based screening and testing for Coronavirus was performed; on the other hand, the possible sources of transmission in communities were identified and cut off. In addition, communities provided medical aid for patients with mild cases of COVID-19. Moreover, social support for community residents, including material and psychosocial support, was provided to balance epidemic control and prevention and its impact on residents' lives. Last and most importantly, special care was provided to vulnerable residents during the epidemic. Conclusion This study systematically reviewed how communities to respond to COVID-19. The findings presented some practical and useful tips for communities still overwhelmed by COVID-19 to deal with the epidemic. Also, some community-based practices reported in this review could provide valuable experiences for community responses to future epidemics.


INTRODUCTION
The outbreak of COVID-19 was reported in December 2019 (1). Considering the fast spread of the epidemic, it was declared a public health emergency of international concern by the World Health Organization (WHO) on January 30, 2020 (2), and further announced as a pandemic on March 11, 2020 (3). Then, the confirmed cases of COVID-19 increased from 987 on January 11, 2020, to 314,181,638 on January 11, 2022, and the death toll from 17 to 5,530,773 (4). Over the past year, the number of daily new cases has shown a fluctuating trend, ranging from 300,000 to 900,000. No downward trend has been reported in sojourns, even after the COVID-19 vaccine has been administered worldwide (3). Therefore, besides promoting vaccination campaigns, the role of epidemic prevention and control actions remains important.
Community cluster infections are a significant cause of the rapid spread of the COVID-19 pandemic; they have been reported in most affected countries in the world (5). In China, the community cluster infection was the primary reason why large numbers of people were infected at the beginning of the outbreak of COVID-19. In this review, "community" refers to "residential community". According to the definition of the WHO, community is "a group of individuals who live together in a specific geographical place, which maintains social relations among its members who recognize that they belong to such a community" (6). Thus, activities that require the community to cluster can facilitate the spread of the epidemic within the community and expose residents to the dangers of the pandemic (7,8). Group gathering and intimate contact are widespread due to often high population density in communities, providing a high possibility for the spread of the epidemic (9). COVID-19 pandemic is highly transmissible with various transmission routes such as airborne, respiratory droplets, and direct close contact. In this sense, communities are more susceptible to the spread of the COVID-19 pandemic (10). The community spread has been reported in many countries (11).
In response to the community spread of COVID-19, the WHO launched a comprehensive guideline on community epidemic prevention, "Responding to community spread of COVID-19: Interim Guidance" on March 7, 2020 (12). Governments from many countries attached great importance to the community spread of the epidemic and took a series of strict measures to prevent and control the epidemic in communities. China, Japan, the United States, and other countries formulated plans for community epidemic prevention. Many communities around the world are exploring countermeasures to contain the epidemic. Although the epidemic is still raging around the world, some measures taken by communities have played important roles in controlling the spread of the epidemic, thus providing valuable experiences for areas still overwhelmed by COVID-19. Furthermore, global experiences of community responses to COVID-19 can also shed some light on global community responses to future pandemics.
A bulk of information exists about the community responses to COVID-19 in different countries. It is necessary to summarize the reported experiences of community responses. Several reviews explored the experiences of certain aspects of community responses to COVID-19, such as face masks (13), hand hygiene (14), contact tracing (15), and risk communication Abbreviations: COVID-19, corona virus disease 2019; PHEIC, public health emergency of international concern; WHO, World Health Organization; MMAT, Mixed Methods Appraisal Tool; UK, United Kingdom; PPE, personal protective equipment; Rt, effective reproduction number; NGOs, non-government organizations; NHS, National Health Service; CIF, community isolation facility; CTF, community treatment facility; CDC, center for disease control and prevention; VHC, virtual health care; CAIH, center for American Indian health; LMICs, low and middle-income countries; CMH, Community mental health. (16). However, a comprehensive review of the experiences of community responses to COVID-19 is lacking. In this study, we searched published articles about community responses to COVID-19 through electronic databases. The global experiences of community responses to COVID-19 will be approached from multiple aspects with different themes via a systematic review of the collected data.

Study Design
In this study, a systematic review was used to investigate the experiences of community responses to COVID-19 (17). Systematic review is a research method for the systematic and objective interpretation of literature content through the classification process of coding and identifying themes (18). Given its potential for interpreting the literature systematically and addressing the richness and uniqueness of the data, systematic review has been widely used in health-related disciplines and fields, including nursing (19), health promotion (20), and health services and management (21). In recent years, health researchers have begun to use this method to describe and summarize the practices and experiences in the health field (22)(23)(24)(25).
This study was conducted based on the methodological approach pioneered by Khan et al., which consisted of the following five stages (26). Stage 1 was to identify the research question, which could guide the way of data collection. Our research question was: How did communities respond to COVID-19 worldwide? Stage 2 was to identify relevant publications. We adopted a scientific strategy to search for the relevant literature, which could answer the research question as much as possible, and employed a systematic mechanism to exclude literature not related to our research question. Stage 3 was to assess the quality of the selected literature. Stage 4 was to chart and analyze the extracted data. A narrative synthesis was used to develop themes and subthemes in this study. The last stage was to report the results and interpret the findings.

Literature Search
Five electronic databases (PubMed, Embase, CINAHL, ScienceDirect, and Web of Science) were used to conduct a thorough search of the published literature related to COVID-19 control and prevention in global residential communities from inception to October 10, 2021. According to the objectives of this review and the PICo template for systematic reviews (27), the search strategy consisted of sets of terms for Population (actors involved in community's response to the COVID-19), the phenomenon of Interest (community measures in response to  and the Context (residential community). Literature search terms (MeSH terms) were used to retrieve relevant studies as much as possible (see Supplementary Material 1). All collected articles were exported into reference management software NoteExpress for convenience management.

Literature Selection
A three-step process proposed by Lockwood et al. (28) was used to review and select the relevant literature closely related to the research question (Figure 1).
First, 2,871 articles were obtained in total. The title of each article was carefully read to exclude the duplicated entries. A total of 1,424 duplicated entries were found, and thus 1,447 records were screened with their titles.
Second, an initial review of the titles was conducted by two independent reviewers to exclude the entries whose titles showed that they were clearly outside the scope of the study. If an agreement on the exclusion of an article could not be reached between those who had read the title, they included it for further review of its full text. A total of 557 articles were excluded at this stage. Among these, 232 records did not involve the residential community. The topics included other forms of the community during COVID-19, such as "oncology community" (29), "virtual community" (30), "nursing community" (31), "deaf community" (32), "East African community" (33), and others. Furthermore, 325 records had no strong correlation with epidemic prevention, and the topics included "risks and vulnerabilities" (34), "community mobility" (35), "fear effect" (36), "mental health" (37), "economic impacts" (38), "living experiences" (39), and so on.
Third, the full texts of 890 remaining articles were read by two independent reviewers to exclude the entries that could not provide a valid representation of the experience of community epidemic prevention and control. Any disagreements at any stage were resolved through discussion with a third reviewer (26). In this step, non-research articles, non-empirical research articles, articles without a clear report of the analytic procedure, and articles not reporting the positive effect of community responses were excluded. Besides, 54 non-English articles were also excluded. Then, 25 articles met the inclusion criteria for this study. In addition, four additional articles were identified through citation tracking.

Quality Appraisal
As this review involved quantitative, qualitative, and mixedmethod studies, the Mixed Methods Appraisal Tool (MMAT) was used to appraise the quality of the included literature (40). MMAT was purposely designed as a checklist for concomitantly appraising the methodological quality of different types of empirical studies (qualitative, quantitative, and mixed-method studies) included in systematic mixed-study reviews (40). The MMAT (Version 2018) provides a set of criteria for screening questions, and a score is made for each study. QZ and YW independently appraised the quality of the included studies, and appraisal disagreements were discussed until consensus was reached (Supplementary Material 2). Given the good quality score of each study, no studies were excluded (41).

Data Extraction
Studies were extracted according to the following characteristics: authors, year, country/region, study quality (MMAT score), study design, study setting, data collection, participants, and key   findings ( Table 1). The first reviewer conducted data extraction, which was re-checked by a second reviewer (YW).

Data Synthesis
As the included studies were a mixture of quantitative, qualitative, and mixed-method studies, a narrative synthesis of the data was conducted using a thematic approach (71). The narrative synthesis aimed to present a descriptive summary of findings across the included studies and generate themes relevant to the aims of this review (72).
In this review, we followed the method for qualitative data synthesis proposed by Elo and Kyngäs, which consisted of three phases (73). In the preparation phase, the core tasks were "deciding on what to analyze in what detail" and "selecting the unit of analysis"; we focused our analysis on the actions/measures against the COVID-19 pandemic (74). In the organizing phase, the core tasks were open coding, creating categories, and the abstraction. For open coding, two researchers read through the article and wrote down headings about community epidemic prevention and control independently (74). For category creation, the lists of headings were grouped under higher-order subthemes, which could provide a good knowledge of community responses to COVID-19 pandemic (75). For data abstraction, sub-themes with content similarities were grouped as main themes (76). In the reporting phase, the analytical process and categories of the results were reported in detail.
To ensure methodological rigor, two researchers (QZ and YW) independently coded all the included literature. Coding disagreements were discussed until consensus was reached (77). In addition, codes were expanded and changed to ensure that they were extremely exhaustive during the coding process (78). PRISMA checklist was provided in Supplementary Material 3 (79).

RESULTS
The characteristics and quality assessments of 29 included studies are shown in Table 1. All of them were published after 2019. Six studies were conducted in the United States, five in China, four in the United Kingdom, three in Hong Kong, two in Italy and Australia, respectively, and one in Belgium, Ireland, Thailand, Turkey, Vietnam, Indonesia, and Sierra Leone, respectively. Thirteen of the 29 included studies used qualitative study design, twelve employed quantitative study design, and four used mixed methods. MMAT findings showed that the quality of included studies was variable, with a mixture of studies having 100% (n = 3), 80% (n = 8), 60% (n = 14), and 40% (n = 4) quality.
The results showed that global experience of community responses to COVID-19 epidemic were composed of the following five themes ( Table 2).

Biotechnology-Based Detection Methods
Biotechnology-based methods for COVID-19 testing have been widely used in communities of developed countries, where medical resources are relatively abundant. Compared with centralized COVID-19 testing, community-based testing has its unique advantages. In a large lower-income community in Arizona, a community pharmacy provided point-ofcare testing services for its residents during the COVID-19 pandemic. Pharmacists were trained to administer COVID-19 tests to their community residents. Residents received a pharmacist-guided nasal self-swab collection and got their results within 24 h by a follow-up phone call (62). The community testing program provided by National Health Service Trust in London also showed that community testing could provide an accurate picture of how many confirmed cases would exist in a community (67). In an Australian indigenous community Yarrabah, communitybased testing was provided by a primary healthcare center. Community-based testing, aside from other measures, successfully prevented the invasion of COVID-19 into Yarrabah community (58). It was also suggested that the nationwide intensive community screening in China was extremely effective in controlling the spread of the COVID-19 epidemic (63).

Non-biotechnology-based Detection Methods
Biotechnology-based detection methods require a large amount of human and medical resources, which pose great challenges for communities. Thus, besides biotechnologybased detection methods, non-biotechnology-based detection methods were also used in community responses to COVID-19. In Vietnam, the community volunteers collected epidemicrelated data from residents, including daily temperature and symptoms of household members (53). In addition, community officials collected residents' travel history and their close contact information in order to identify at-risk cases (53). The suspected cases were reported to the local health authority, which decided whether they needed testing, isolation, quarantine, or hospitalization. This ensured the early detection of high-risk cases and prevented the spread of COVID-19 in communities (53). In China, community officials aside from volunteers contacted each resident to determine whether they had been in close contact with confirmed patients. The screening information was shared with the local Center for Disease Control and Prevention (CDC) for further measures (48).

Cutting Off the Transmission Chain of the COVID-19
This theme examined how residential communities cut off the transmission chain of COVID-19. This theme involved nine studies (48-50, 53, 55, 56, 58, 69, 70). Two subthemes underpinned this theme, that is, preventing the invasion of the COVID-19 into the community and preventing cross-infection in the community.

Preventing the Invasion of the COVID-19 Into the Community
Community closure was carried out to prevent the invasion of COVID-19 into the community. Different countries adopted different strategies for community closure with different stringencies. A community called Yarrabah in Australia implemented limited "community lockdown" measure, which required that all residents should undergo a 14-day isolation before entry or re-entry into Yarrabah. Note that residents who were in urgent circumstances were exempt from travel restrictions. For example, community residents suffering from illnesses were allowed to travel to the designated hospitals outside the community for short-term medical treatment (58). Some communities in China adopted complete community closure. For instance, an 18-day community lockdown was implemented in the Yuanqiao community in Zhejiang province of China, and all residents were not allowed to leave their homes unless for a permitted reason. The local government and community-based organizations provided food (pork, vegetables, eggs, rice, cooking oil, etc.) for the residents living in the Yuanqiao community to help them get through the quarantine period (48). Community closure proved effective in preventing the community spread of the COVID-19.

Preventing Cross-Infection in the Community
Multiple measures have been adopted to prevent cross-infection in the community. Mask wearing, an initiative from the WHO, is the most widely used measure across the global communities. More evidence has shown that community-wide mask wearing can help stop the spread of COVID-19. Data from Hong Kong communities showed that community-wide mask wearing contributed to the control of COVID-19 by reducing the amount of emission of infected saliva and respiratory droplets from infected patients (49). The surveys on communities in the United States and China also showed that community-based mask wearing limited the community transmission of the virus (55,69). Social distancing is another effective way for community epidemic prevention, preventing disease transmission by reducing close contact between people. Social distancing consists of a range of concrete measures, including public place closure, gathering cancellation, avoiding close contact with other people, and staying at home. Data from Google Mobility Reports in Turkey showed that the community-based social distancing interventions (e.g., public place closure. travel restrictions, and cancellation of religious activities) significantly decreased the transmission of COVID-19 by reducing human mobility, and thereby prevented residents from becoming infected (50). In addition, community-based social distancing (e.g., avoiding taking public transport and engaging in social activities, and keeping a distance of 6 feet from others in a public space) played an important role in stopping the transmission of COVID-19 in Southeast Minnesota, the United States, and Hong Kong, China (55,56).
Quarantine, one of the oldest and most effective tools for controlling the spread of communicable diseases, has also been used to stop the community spread of COVID-19. The WHO recommends that the contacts of patients with COVID-19 must be quarantined for 14 days from their last contact with the patient. These measures are adopted by many countries, but the range of residents required to be quarantined varies from country to country. In some residential areas of developed countries such as Australia, suspected cases need to be quarantined based on biotechnology-based testing (58). However, in some developing countries, suspected patients were quarantined at home based on mass non-biotechnology-based community screening. For example, in Vietnam, residents who traveled to the pandemic epicenter needed to be quarantined at home (53). In China, close contacts, travelers from the pandemic epicenter, and residents with a high fever for a week had to undergo 14 days of home quarantine (69). It was suggested that community quarantine of residents with suspected symptoms and clear exposure history significantly reduced the risk of the outbreak of COVID-19 in Anhui province of China (70).

Providing Medical Aid for Mild Cases
This theme concerned how residential communities provided home-based medical aid for infected patients with mild symptoms. At the beginning of the epidemic, medical facilities did not have sufficient capacity for admitting patients. Thus, some communities tried to provide medical aid for their residents with mild symptoms. Hong Kong built community isolation facilities (CIF) and community treatment facilities (CTF) for symptomatic patients who did not require advanced medical resources. CIF and CTF accompanied by meticulous infection control measures (staff training, audit, staff and patient hand hygiene, and direct observation of donning and doffing) proved to be a feasible and safe approach to combat the epidemic (68).
In addition to centralized surveillance and care, some countries explored virtual observation and care to meet the challenge of housing and personnel storage. In New South Wales, Australia, virtual health care was established by Sydney Local Health District (SLHD) to monitor the residents' body condition, including respiratory rate, oxygen saturation, pulse rate, and temperature. Patients who were quarantined at home were contacted by video conference software twice every 24 h to recognize the signs and symptoms related to their deteriorating conditions. The deteriorating patients were transferred to the local emergency department by ambulances (54).

Social Support for the Residents
Seven studies highlighted community's social support for the residents (44,45,47,48,60,65,66). This theme consisted of two sub-themes, that is, material support and psychosocial support.

Material Support
In response to the movement restrictions imposed by the lockdown measures, some communities provided food supplies to their residents. For example, in a community called Yuanqiao in the Zhejiang province of China, a 18-day community lockdown was implemented. The local government and community-based organizations delivered food (e.g., pork, vegetables, eggs, rice, and cooking oil) to the residents who were not allowed to leave their homes during the quarantine period.
Due to these efforts, the degree of complaints about the longtime lockdown was significantly reduced (48). In terms of food insecurity, the communities in Bangkok and Thailand adopted multiple measures (e.g., community pantry and community gardening) to ensure food security (60). In two Indonesian villages (Urug and Cipatat Kolot), the residents experienced a severe food shortage because the food markets were suspended from operations. The food shortages were addressed by charitable donations. Different types of social organizations took part in food provision and allocation to the vulnerable groups (orphans, elderly people, widows, etc.) (45).

Psychosocial Support
Some communities adopted "risk communication" to establish trusted communication channels with their residents. In communities of Ireland, culturally appropriate communication strategies were used to increase community trust (66). To be specific, the culture (norms, beliefs, and values) of the target population was fully considered. In this sense, communication strategy would be more likely to be accepted by the target population (66). In the Orthodox Jewish communities of Antwerp, Belgium, a community-based communication strategy was used to promote risk communication with their residents. In addition, community volunteers operated a telephone "hotline, " to which community residents could turn for help when they were in trouble. Furthermore, the risk communication performed by community leaders in Orthodox was also proved to be of great importance in fostering a feeling of resident trust in the government (65).
Along with risk communication, mental health services were provided to community residents during the epidemic. The Johns Hopkins Center for American Indian Health delivered holistic wellness boxes (e.g., cards with teachings on dealing with stress, lavender essential oil for practicing mindfulness, and storybooks for encouraging children) to indigenous communities in the United States and Canada, which relieved their psychosocial problems effectively (44). An online art therapy group from the United Kingdom delivered online therapy to the community residents. They were encouraged to share artworks they made and discuss their images and techniques used, which helped them build resilience, increase self-awareness, and improve selfesteem (47).

Protecting Vulnerable Residents During the Epidemic
This theme addressed eight studies that focused on protecting vulnerable residents during the epidemic (43, 46, 52, 57-59, 61, 64). Two subthemes underpinned this theme: physical health service for physically disadvantaged residents and mental health service for spiritually vulnerable residents.

Physical Health Service for Physically Disadvantaged Residents
Residents with severe or chronic diseases are more vulnerable to the COVID-19 epidemic. Many medical institutions tried to reform their working models to sustain their medical services for vulnerable individuals. A community dialysis center in Georgia, the United States, implemented a range of measures (e.g., screening tests, wearing masks for all individuals, reducing patient wait times, telemedicine, and isolation room for suspected or confirmed patients) for infection prevention and control and could thus be able to continue providing patients with hemodialysis services (43). Also, pharmacies in Piedmont communities of Italy adopted some effective strategies (e.g., personal hygiene measures, disinfection in public spaces, social distancing, universal masking, and confirmed staff being placed under quarantine) to stop the spread of the virus among pharmacists, which could ensure that they could provide safe health care to their community residents (46). In addition, many community health facilities offered telehealth services for their residents during this epidemic. Community pharmacies in the South East of England reformed their service modes and implemented innovative services, which consisted of home medication delivery services, tailored services, and telephone consultations (57). This benefited community-based dementia patients a lot (57). In Italy, telehealth performed by community pharmacies was proved to a feasible and useful way to monitor the health status (e.g., ambulatory blood pressure, spirometry, and sleep oximetry) of community patients during the epidemic (61).

Mental Health Service for Spiritually Vulnerable Residents
Some residents felt stressed, worried, or anxious during the epidemic. Thus, communities tried to provide psychological comforts for their residents. For example, American Indians and Alaska Natives were at a higher risk of suicide than any other racial or ethnic groups in the United States (64). Thus, these individuals were provided with online consulting services via video conferencing platforms, telephone, e-mail, or texting, which were effective in preventing suicides (64). In addition, a social and emotional wellbeing team was established in a community called Yarrabah in Australia, which provided home-based mental health services for community residents experiencing elevated fear, anxiety, grief, and trauma (58).

Principal Findings
This study revealed some common experiences of community responses to the COVID-19 epidemic. First, this review found that the viral screening test was mostly used to stop the spread of the virus in the community, and untimely or delayed screening may cause community spread. In addition, immediate measures were taken to cut off the transmission route of the virus, which is in line with many previous studies (80,81). Some measures were community-oriented measures, such as community closure and home quarantine. Whole-of-society measures including mask wearing and social distancing were also implemented in the community setting. Second, it is of great importance to balance epidemic management and residents' daily lives. As mentioned earlier, some measures, such as community closure and social activity restrictions, may influence the normal lives of residents. Thus, some community services, including material and psychological support, were used to balance epidemic management and residents' lives. Third, vulnerable individuals have been given more attention during the epidemic (82,83). Vulnerable individuals may suffer more from COVID-19, thus a range of measures have been taken, including physical health service for physically disadvantaged residents and mental health service for spiritually vulnerable residents. Fourth, the participation of multiple actors is the key to the success of community epidemic control and prevention. Many actors are involved in community response to the epidemic, including the government, community organizations, community hospitals and medical centers, pharmacists, community workers, volunteers, residents, NGOs, business organizations, and so on. The participation of multiple actors, also known as community engagement, can give full play to the strengths of different actors in different tasks of epidemic prevention, such as plan designing, trust building, risk communication, surveillance and tracing, resource supply, trust building, and protection of vulnerable groups (84)(85)(86)(87).
The global experiences of community responses to COVID-19 is a rich database for future epidemic prevention and control in the community. However, no "one-size-fits-all" model exists for community epidemic prevention and control, and many of these experiences cannot be replicated directly in every instance. Some preconditions need to be considered in the design of community measures.
First, measures taken by communities need to be commensurate with the affordability of the national economy. Some measures such as social distancing and societal closure have proven highly effective at reducing the community transmission of COVID-19. However, these measures may cause social and economic damage (88,89). For example, a study showed that the lockdown measure in Chile was associated with a 10-15% drop in local economic activity, which was twice the reduction in local economic activity suffered by municipalities that were not under lockdown. A 3-to-4 month lockdown had a similar effect on economic activity than a year of the 2009 great recession (90). In low-and middle-income countries, strict social distancing measures (e.g., nationwide lockdown) in response to the COVID-19 pandemic are unsustainable in the long term due to knock-on socioeconomic and psychological effects. Compared with prolonged lockdown, zonal or local lockdowns may be a better option for these countries (91). Therefore, resources and economic capacity should be taken into full account when designing and taking epidemic prevention measures.
Second, existing health system capabilities, as the basis of prevention measures, cannot be ignored. For example, a strategy of limited lockdown of an objectively identified selected highrisk population might be a cost-effective option compared with a generalized lockdown. However, limited lockdown is more commonly used in developed countries rather than in developing ones. It can involve comprehensive biotechnologybased screening for suspected cases and thorough tracing of contacts based on adequate medical resources and a wellsupported, community-based team of trained personnel, which are often not available in developing countries (92,93). Health system capabilities define possible boundaries for community prevention measures.
Third, a country's social culture needs to be considered. For example, epidemic-relevant information registration is accepted by East Asian countries such as China, Japan, and Singapore (94,95) but may be considered an infringement of privacy in Western countries (96,97). In addition, home quarantine, which is widely used in China, India, and Vietnam, may be considered a restriction on personal freedom in Western countries (98,99).
Fourth, community epidemic prevention and control need to be commensurate with the national concepts of epidemic prevention. Taking "cutting off the transmission route of the virus" as an example, community closure, social distancing (public places closure and gathering cancellation), quarantine, and travel restrictions are collectively referred to as community containment strategies (100). However, personal protective measures (handwashing, cough etiquette, and face mask), social distancing (maintaining physical distance between persons in community settings and staying at home), and cleaning and disinfection in community settings are collectively referred to as community mitigation strategies (9). Some countries (e.g., China and Singapore) tend to use community containment strategies, whereas others (e.g., the UK) prefer to use community mitigation strategies (101).
Finally, the unique circumstances of each community should be considered. Just as CDC Community Mitigation Framework (the United States) reported, each community is unique, and prevention strategies should be carried out based on the characteristics of each community (102). Specifically, different communities vary significantly in economic conditions (103), population density (104), vulnerability degree (105), physical environment (106), health facilities (107), and so on. Thus, these factors should be fully considered by policymakers when making prevention measures. In this sense, it seems that no "one-size-fits all" approach exists to fight COVID-19 in the community, and multiple contextual factors should be taken into full account.

Strengths and Limitations
In this review, we made a comprehensive analysis of community responses to COVID-19, which could provide not only a comprehensive understanding of community responses to COVID-19, but also insightful findings that could not be obtained by a review focusing mainly on a single measure. Although this review followed a rigorous process of systemic literature review, it could not be guaranteed that this review could fully reflect "global experiences of community responses to COVID-19." As with all literature reviews, five electronic databases rather than all electronic databases were used for searching the literature due to the huge cost of searching all the databases (108,109). Accordingly, some relevant studies might be missing in this review. The eligibility criteria were used for literature selection. Therefore, some relevant studies (gray literature, non-English literature, etc.) could not be included in this review (110,111).

CONCLUSIONS
Communities around the world took multiple measures to fight against the epidemic. Community responses to COVID-19 consisted mainly of five ways. On the one hand, communitybased screening and testing for Coronavirus was performed; on the other hand, the possible sources of transmission in communities were identified and cut off. In addition, communities provided medical aid for patients with mild cases of COVID-19. Moreover, social support for community residents, including material and psychosocial support, was provided to balance epidemic control and prevention and its impact on residents' lives. Last and most importantly, special care was provided to vulnerable residents during the epidemic. The findings presented some practical and useful tips for communities still overwhelmed by COVID-19 to deal with the epidemic. Also, some community-based practices reported in this review could provide valuable experiences for community responses to future epidemics.

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

AUTHOR CONTRIBUTIONS
QZ conceived the study and all authors participated in its design. YW drafted the manuscript. ML, QM, and LL have been involved in discussing earlier versions of the text. All authors read and approved the final manuscript.

FUNDING
This research was supported by the Natural Science Foundation of Shandong Province, China (Grant ID: ZR2021QG015). The funding body did not influence this paper in any way prior to circulation.