Behavioral Intention of Receiving Monkeypox Vaccination and Undergoing Monkeypox Testing and the Associated Factors Among Young Men Who Have Sex With Men in China: Large Cross-Sectional Study

Background: The worldwide human monkeypox (mpox) outbreak in 2022 mainly affected men who have sex with men (MSM). In China, young men who have sex with men (YMSM) were at a potential high risk of mpox infection due to their sexual activeness and the eased COVID-19 restrictions at the end of 2022. Objective: This study aimed to investigate the behavioral intention of receiving mpox vaccination and undergoing mpox testing in 4 different scenarios and explore their associations with background and behavioral theory–related factors


Introduction
Since May 2022, rapidly growing numbers of human monkeypox (mpox) cases have been reported from countries where the disease was not initially endemic [1,2].The World Health Organization (WHO) declared the worldwide mpox outbreak a public health emergency of international concern on July 23 [3].By September 28, 2023, a total of 90,618 confirmed cases were reported across 115 countries, with 1484 confirmed cases in China.Among cases with known data on sexual orientation, 83.2% patients were identified as men who have sex with men (MSM) worldwide [4].In China, more than 90% cases were identified as MSM [5].One potential reason for MSM being the most affected population is that mpox transmission can result from close contact with the skin lesions of an infected person [1] and MSM communities usually have highly interconnected sexual networks [6].
China has the largest MSM population in the world, with an estimated size of 8.3 million [7], and among them, approximately 1.9 million are young people attending universities [8].The first mpox case in mainland China was reported on September 16, 2022, and the patient was an MSM.The risk of an mpox outbreak became a public concern due to the large MSM population and the eased COVID-19 restrictions (eg, travel restrictions, social distancing) [9].WHO recommended that the state parties with recently imported cases of mpox implement a coordinated response with a priority focus on the most affected communities [10].
Case detection and targeted immunization are powerful measures to fight the mpox outbreak [10][11][12].Timely mpox testing can reduce mpox transmission, avoid delays in mpox treatment, and decrease the cost of health care [11][12][13][14][15]. Vaccination, such as that against smallpox, has been demonstrated to be highly cost-effective in preventing mpox infection [16].Several classic theories postulate factors causing health-related behaviors and the underlying mechanisms.For example, the knowledge attitude practice (KAP) model [17] argues that knowledge of a disease and the related preventive/risk behaviors influences an individual's attitude toward the behaviors and, in turn, affects the behaviors.The Health Belief Model (HBM) [18] proposes that people are more likely to take preventative actions if they perceive the threat of a health risk to be serious, feel they are personally susceptible, and perceive fewer costs than benefits of engaging in it.The theory of planned behavior (TPB) [19] says that attitudes, social norms, and perceived control of behaviors are predictors of behavioral intention.According to these theories and previous studies on other sexually associated infectious diseases, several factors may affect the behavioral intention of receiving mpox vaccination and undergoing mpox testing among MSM, including general factors (eg, sociodemographic characteristics, risk behaviors, disease knowledge, perceptions of health behaviors) and MSM-specific factors (eg, stigma) [20,21].Although a large body of literature has examined preventive behaviors of diseases associated with MSM (eg, HIV/AIDS, sexually transmitted diseases [STDs], human papillomavirus [HPV]), the situation of mpox might be different, as it is a newly emerging disease in MSM communities.To timely inform the mpox prevention and control strategies in China, a comprehensive investigation on the behavioral intention of adopting mpox prevention measures and associated factors is warranted.
This study aimed to investigate the levels of the behavioral intention of receiving mpox vaccination and undergoing mpox testing among Chinese young men who have sex with men (YMSM) aged 18-29 years and to explore the associated factors.This age group was selected as it became the population with a high risk of mpox infection, especially after COVID-19 travel restrictions were eased in China.YMSM are the most socially active subgroup within MSM communities [22], have relatively more opportunities to meet people from abroad due to study or business reasons, and have not received smallpox vaccination, as China ended this immunization program in 1981 [23].The hypotheses of potential factors were guided by the KAP model [17], the HBM [18], and the TPB [19].

Study Design
An online cross-sectional survey was conducted in September 2022 with participants from 6 provincial regions of China, which represented the country geographically and socioeconomically (based on the per capita gross domestic product [GDP] of 2020) to some extent [7,24].These 6 regions were Beijing (the capital; Figure 1 shows the geographic location, per capita GDP, population size, and sample size of the study areas.

Participant Recruitment and Data Collection
The inclusion criteria were male participants, age 18-29 years, having ever had anal or oral sex with men, and ability to fill an electronic questionnaire and provide oral informed consent.The exclusion criteria were psychiatric disorders based on the recruiters' report and refusal to participate.
The facility-based sampling method was used to recruit participants from each province with the assistance of local MSM-oriented community-based organizations (CBOs).The selected CBOs have rich experience in providing health services (eg, HIV/sexually transmitted infection [STI] testing) and conducting public health studies in MSM communities.First, CBO staff were trained as recruiters and asked to disseminate the invitation message to potentially eligible YMSM in their networks via commonly used messaging apps (eg, WeChat).YMSM who were interested in the study were then screened for eligibility and fully informed about the study.Next, they were sent a quick response (QR) code and a 1-time password to access the electronic anonymous questionnaire.The self-administered questionnaire took about 10-15 minutes to complete.
The recruitment rate of the study (number of returned questionnaires/number of invitations sent) was 67.2% (2918/4342).In each province, the recruitment rate ranged from 44.5% to 97.2%.The main reasons for nonparticipation (n=1424, 32.8%) reported by the recruiters were not meeting the inclusion criteria, lack of time, and privacy concerns.The 2918 participants completed the questionnaire, and 425 (14.6%) were excluded from analysis due to a failure in the quality check.The final sample size was 2493 (85.4%) participants.

Ethical Considerations
The study was approved by the Institutional Review Board of Tsinghua University, China (reference number: 20220140).Each participant was asked to carefully read the informed consent form before starting the survey, in which the objective, procedure, potential risks and benefits, and voluntary nature of the study were clearly stated.Oral informed consent was obtained before any data collection.Written informed consent was waived to protect the participants' privacy.The questionnaire was fully anonymous and self-administered by the participants through a secure privacy-compliant platform (Wenjuanxing survey platform [25]).Each participant whose submitted questionnaire passed the quality check receive Chinese yuan [CNY] 15 (about US $2.10) via the survey platform for compensation of their time and effort.To ensure confidentiality, further deidentified data were used for analysis.

Behavioral Intention of Receiving Mpox Vaccination and Undergoing Mpox Testing
All the measures are described in detail in Multimedia Appendix 1. Regarding behavioral intention, the participants were asked to rate their likelihood (1=very unlikely to 5=very likely) of receiving mpox vaccination in 4 scenarios.A summative score was calculated, with a higher score indicating a higher level of intention (range 4-20, α=.90).Similarly, the participants were asked to rate their likelihood of undergoing an mpox test in 4 scenarios, with a higher summative score indicating a higher level of intention (range 4-20, α=.94).

Mpox Knowledge
Mpox knowledge was measured with a single yes/no question ("Have you heard of mpox?") and 10 knowledge questions.A composite score of the knowledge scale was constructed by counting the number of correct responses to the questions; those who had not heard of mpox were assigned a score of 0 (score range 0-10).A higher score indicated a higher level of knowledge (α for the 10 knowledge questions=.77).

Mpox Cognition
The perceived susceptibility of mpox was measured with 3 items, with responses ranging from 1 for very unlikely to 5 for very likely.A higher total score implied a higher level of perceived susceptibility (range 3-15, α=.83).The perceived severity of mpox was measured with 2 items, with responses ranging from 1 for very mild to 5 for very strong.A higher summative score indicated a higher level of perceived severity (range 2-10, α=.90).Emotional distress (eg, panic, anxiety) caused by the mpox outbreak was measured with a single item, with the response ranging from 1 for very mild to 5 for very strong.

Cognition of Mpox Vaccination and Testing
Participants were asked about the perceived benefits, barriers, and self-efficacy of mpox vaccination/testing, with responses ranging from 1 for strongly disagree to 5 for strongly agree.The perceived benefits of mpox vaccination were assessed with 4 items (range 4-20, α=.90), and the perceived benefits of mpox testing were measured with 3 items (range 3-15, α=.91), with a higher summative score indicating more perceived benefits.The perceived barriers to mpox vaccination were measured with 4 items (range 4-20, α=.81), and the perceived barriers to mpox testing were measured with 5 items (range 5-25, α=.82), with a higher total score indicating more perceived barriers.The self-efficacy of mpox vaccination was measured with 2 items, with a higher summative score indicating a higher level of self-efficacy (range 2-10, α=.82).The self-efficacy of mpox testing was similarly measured (range 2-10, α=.85).

Background Information
Background information was collected, including (1) sociodemographic characteristics, (2) mpox risk behaviors in the past 6 months (eg, overseas travel history, number of male sex partners, frequency of in-person gatherings with MSM, use of any psychoactive substance before/during sexual intercourse [chemsex]), (3) diagnosis of HIV and STDs, and (4) presence of mpox-related symptoms in the past 2 weeks.

Statistical Analysis
First, descriptive analyses were conducted, with means and SDs being reported for continuous variables and frequencies and percentages being reported for categorical variables.Second, the q-statistic Geodetector, a spatial variance analysis method that explains nonlinear associations, was used to measure and attribute the stratified heterogeneity [26].The factor detector was applied to detect the spatial association between explanatory variables (ie, study sites, sociodemographic characteristics, and mpox risk behaviors) and response variables (ie, behavioral intention of receiving mpox vaccination and undergoing mpox testing).The q-statistic and P value of Geodetector were reported.Third, simple regression analyses were performed to explore the crude associations between the background/behavioral theory-related factors and behavioral intention.Fourth, multivariate linear regressions were performed, involving all the background and theoretical factors as independent variables.The point estimate and 95% CIs were reported.SPSS Statistics 24.0 (IBM Corporation) was used.Geodetector analysis was conducted using R version 4.3.1 (R Foundation for Statistical Computing).

Behavioral Intention of Receiving Mpox Vaccination and Undergoing Mpox Testing
The prevalence of having a behavioral intention of receiving mpox vaccination varied in different scenarios (n=1651, 66.2%, when there was no local case reported; n=1971, 79.1%, when there was no local case reported and the vaccine was free; n=2112, 84.7%, when there were local cases reported; and n=2204, 88.4%, when there were local cases reported and the vaccine was free; mean 16.8, SD 3.6).See Table 3 and Figure 3A.The prevalence of having a behavioral intention of undergoing mpox testing was above 90% in different scenarios (n=2302, 92.3%, when they had mpox symptoms; n=2324, 93.2%, when they had mpox symptoms and testing was free; n=2320, 93.1%, when they had close contact with patients with mpox; and n=2342, 93.9%, when they had close contact with patients with mpox and testing was free; mean 18.5, SD 2.5).See Table 4 and Figure 3B.

Stratified Heterogeneity of Behavioral Intention of Receiving Mpox Vaccination and Undergoing Mpox Testing
As presented in Table 5, no heterogeneity was observed in the behavioral intention of receiving mpox vaccination and undergoing mpox testing across study sites and socioeconomic characteristics.However, heterogeneity was observed in the behavioral intention of receiving mpox vaccination in a number of male sexual partners (q=0.005,P=.04).In addition, heterogeneity was observed in the behavioral intention of undergoing mpox testing in in-person gatherings with MSM (q=0.002,P<.001).

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Table 7. Univariate and multivariate regression analyses of the behavioral intention of undergoing mpox a testing among YMSM b from 6 provinces of China in September 2022 (N=2493).

Principal Findings
This was among the earliest studies in China examining the levels and factors of the behavioral intention of receiving mpox vaccination and undergoing mpox testing among YMSM.After the COVID-19 travel restrictions were eased in China at the end of 2022, this specific age population became the group with a high risk of mpox infection due to its social activeness.The study findings shed some light on the preparedness for mpox prevention and control in the country.

Comparison With Prior Work
Overall, about two-thirds of the surveyed YMSM intended to receive the mpox vaccination if there was no case present locally, and the prevalence increased to 84.7% if local cases were reported.The latter prevalence was higher than that in 2 other countries with an mpox outbreak.A recent study in the Netherlands showed that 70% of MSM (56.6% aged <45 years) had an intention of getting vaccinated [27].Another study in France found that 33.6% of MSM (80.6% between 30 and 59 years old) declared their hesitancy to get vaccinated against mpox [28].Age may be a potential reason for the relatively high prevalence, as YMSM tend to be more open to newly emerging health services (eg, pre-exposure prophylaxis [PrEP], HPV vaccines) [29][30][31].The finding implies that it is important to keep MSM informed about the most up-to-date mpox statistics.It may assist them in decision-making about adopting preventive behaviors.Furthermore, the study found the prevalence of vaccination intention increased to some extent if the vaccination was free.This indicates that cost may be a barrier to mpox vaccination.The study showed about half of the participants expressed a concern about the potential high cost of vaccination, which is consistent with previous research [32].Therefore, free or subsidized immunization for the high-risk population is recommended to be considered in the future national response.
In this study, over 90% of the participants reported an intention of undergoing an mpox test regardless of the presence of symptoms and the cost.A possible explanation for the high prevalence is that the participants may be knowledgeable about the benefits of testing.As shown in the study, most participants agreed/strongly agreed with the stated benefits of testing.The mass HIV testing campaigns in the past decades may have contributed to these perceptions.Our data showed that only 4.4% of the participants had never been tested for HIV before.Furthermore, the COVID-19 battle since 2020 may have improved people's health literacy, which may, in turn, have positively affected their attitudes and practices of other health behaviors [33][34][35].Lessons learned from the previous HIV testing campaigns targeting MSM and the COVID-19 testing campaign can be drawn by the future promotion of mpox testing in China [3,35].For instance, it is imperative to remove structural barriers to testing (eg, provide anonymous tests) and offer culturally congruent services.Additionally, mpox testing is recommended to be provided in community settings, CBOs, and sexual health clinics trusted by MSM populations.
Guided by the classic health behavioral theories, we identified several factors associated with the behavioral intention of receiving mpox vaccination and undergoing mpox testing.First, according to the KAP model, knowledge is the foremost factor affecting the practice of preventive behaviors [17].Previous studies have demonstrated that disease knowledge is positively associated with HIV testing and COVID-19-preventive behaviors [36,37].Multivariate regression indicated a moderate association between mpox knowledge and vaccination intention and a statistically insignificant association between mpox knowledge and testing intention.The findings suggest that disease knowledge may play a role in motivating the intention of adopting preventive behaviors, but the strength and magnitude of the effect may be limited.Increasing mpox knowledge is important but far from enough in the future response to mpox in China.
The study found that 3 HBM constructs (perceived severity of mpox, perceived benefits of mpox vaccination/testing, and self-efficacy of mpox vaccination/testing) are independently and positively associated with vaccination and testing intentions.The findings are consistent with previous evidence on other diseases, such as COVID-19 and H1N1 [38,39].Meanwhile, 2 other HBM constructs, perceived susceptibility of mpox and perceived barriers to the corresponding service, were also significantly associated with the vaccination intention but not with the testing intention.A possible reason is that the level of testing intention was particularly high in the study and the influence of the 2 factors were limited.Overall, these findings evidence that the HBM is a useful framework to predict health behaviors.Some related components are recommended for future mpox interventions, such as timely updating and disseminating mpox statistics, implementing targeted risk communication, educating the community about the benefits and ways of access to testing and vaccination, ensuring the privacy and confidentiality of services, and debunking and refuting misinformation promptly [40,41].
An interesting finding of this study was that the emotional distress caused by mpox is positively associated with the vaccination intention but negatively associated with the testing intention.It is understandable that YMSM who have experienced more emotional distress due to mpox might be more worried about mpox infection and thus intend to receive immunization.This is in line with previous research showing that people with more emotional distress caused by COVID-19 were more likely to receive COVID-19 vaccination [42].In contrast, it is speculated that some YMSM were emotionally distressed because they were afraid that the testing result would be positive or the result would be revealed to others.Such fears consequently hindered their willingness to undergo testing.Our data showed that 55% of the participants were worried that their testing results might be positive, while 61.9% were worried that the testing results might be leaked to others.A previous HIV study also indicated that emotional distress is a major barrier to seeking HIV-testing services [43].The opposite results remind us that it is necessary to monitor the mental status in the affected community during an emergency and provide timely advice on positive coping strategies.
Stratified heterogeneity analysis revealed variations in the behavioral intention among people with or without mpox risk behaviors.Certain mpox risk behaviors presented significant associations with the intention of receiving mpox vaccination and undergoing mpox testing.Those who had 1 male sex partner in the past 6 months were more intended to uptake both vaccination and testing services compared to those with none or multiple partners.It is understandable that MSM without sex partners recently might think they have no risk of infection and thus have no need to receive the vaccination or undergo testing, while MSM with multiple partners might possess a lower level of health literacy and risk perceptions [44].The finding warns us that MSM with multiple sexual partners may have a lower intention of adopting preventive behaviors against mpox and should be given a priority focus in the future fight against mpox.In addition, attending in-person gatherings with MSM and traveling overseas in the past 6 months were both positively associated with the testing intention.The findings are expected because they are known risk factors of mpox infection [45,46].
It is worth noting that YMSM are at high risk of not only mpox but also HIV/AIDS.Evidence shows that mpox is an opportunistic infection of HIV/AIDS [47].China has a XSL • FO RenderX well-established comprehensive public health system for HIV/AIDS health promotion, testing, treatment, and management, which is considered highly effective for HIV/AIDS high-risk groups.Therefore, it is highly recommended to integrate mpox-related health services and prevention actions into the existing HIV/AIDS prevention and control system.For example, it may be feasible and cost-effective to provide mpox vaccination and testing services at the current HIV testing and counseling sites that are often operated by MSM-friendly CBOs and clinics.It is also important to empower MSM communities and highly involve them, especially the key persons in the communities, in targeted health communication, health counseling, and testing and treatment referrals.This integrated approach is key to addressing the interconnected health challenges faced by YMSM.

Limitations
The study has a few limitations.First, selection bias might exist due to the facility-based sampling and refusal to participate.YMSM who could be approached in this study might be more likely to interact positively with CBOs, receive health education information more frequently, and have a higher level of health literacy.Driven by self-selection, YMSM who were invited but refused to participate might tend to have more concerns about this sensitive topic and their privacy.These systematic difference biases potentially resulted in an overestimation of the behavioral intention related to mpox vaccination and testing.However, as MSM groups are hidden populations, the convenient sampling method is a common way for recruitment.In addition, data were collected from August to September 2022, when China was still under strict COVID-19 restrictions.The recruitment rate may have also been impacted by the pandemic.Second, due to self-reporting, social desirability bias might exist and lead to an overestimation of the behavioral intention.Third, the study was conducted in 6 provincial regions of China and focused on YMSM aged 18-29 years.The generalization of the study findings to broader populations should be made with caution.Fourth, the cross-sectional design allowed a limited ability of causal inferences.Longitudinal studies are warranted.

Conclusion
The majority of the YMSM in this study showed an intention of receiving mpox vaccination, and the intention was somewhat sensitive to the epidemic status and cost.Most of the YMSM had an intention of undergoing an mpox test regardless of scenarios.It is recommended that the future national response to mpox in China prioritize groups with high-risk exposure, raise their mpox knowledge, promote cognition of the disease and preventive measures, improve accessibility and privacy of health services, monitor the mental health status of the groups, and provide advice on positive coping strategies.

Figure 1 .
Figure 1.Map of the geographic location, per capita GDP, population size, and sample size of the 6 study sites in China.Note: The per capita GDP and population size of each study site were based on the data released by the National Bureau of Statistics of China in 2020.GDP: gross domestic product.
5.7 (2.7)Total mpox knowledge score ranging from 0 to 10, mean (SD) Perceived susceptibility (frequency of choosing likely and very likely), n (%) 91 (3.7) Likelihood of being infected with mpox 157 (6.3) Likelihood of having close contact with patients with mpox 425 (17.0)Likelihood of an mpox outbreak in China 6.1 (2.3)Total perceived susceptibility score ranging from 3 to 15, mean (SD) Perceived severity (frequency of choosing strong and very strong), n (%) 2035 (81.6)Perceived negative impact of mpox infection on your health 2073 (83.2) Perceived negative impact of mpox infection on your life 8.4 (1.9)Total perceived severity score ranging from 2 to 10, mean (SD) Emotional distress caused by mpox (frequency of choosing strong and very strong), n (%) 605 (24.3)Emotional distress caused by the mpox epidemic (eg, panic, anxiety) 2.7 (1.2) Total emotional distress score ranging from 1 to 5, mean (SD) a mpox: monkeypox.b YMSM: young men who have sex with men.

16. 6
(2.9)   Total perceived benefits score ranging from 4 to 20, mean (SD) Perceived barriers to mpox vaccination (frequency of choosing agree and strongly agree), n (%) 1316 (52.8)I am worried that the vaccination fee might be high.1002 (40.2) I am worried that my MSM c identity might be revealed due to vaccination.1230 (49.3)I am worried that receiving vaccination might be inconvenient.1598 (64.1)I am worried that the vaccine might have side effects.13.8 (3.5)Total perceived barriers score ranging from 4 to 20, mean (SD) Self-efficacy of mpox vaccination (frequency of choosing agree and strongly agree), n (%) 1717 (68.9)I am confident in taking mpox vaccination.1490 (59.8)I think it is easy for me to take mpox vaccination if I want.7.5 (1.5)Total self-efficacy score ranging from 2 to 10, mean (SD) a mpox: monkeypox.b YMSM: young men who have sex with men.c MSM: men who have sex with men.

Table 4 .
Behavioral intention and cognition related to mpox a testing among YMSM b from 6 provinces of China in September 2022 (N=2493).Value Variables Intention of getting mpox testing by scenario (frequency of choosing likely and very likely), n (%) 2302 (92.3)When I had mpox symptoms 2324 (93.2) When I had mpox symptoms and testing was free 2320 (93.1)When I had close contact with patients with mpox 2342 (93.9)When I had close contact with patients with mpox and testing was free 18.5 (2.5)Total intention score ranging from 4 to 20, mean (SD) Perceived benefits of mpox testing (frequency of choosing agree and strongly agree), n (%) 2300 (92.3)It can help me know in time whether I have an mpox infection.2249 (90.2) It can protect people around me from mpox infection.2293 (92.0)It can assist the country in preventing and managing mpox epidemics.13.4 (1.9)Total perceived benefits score ranging from 3 to 15, mean (SD) Perceived barriers to mpox testing (frequency of choosing agree and strongly agree), n (%) 1495 (60.0)I am worried that the testing fee might be high.1091 (43.8)I am worried that my MSM c identity might be revealed due to testing.1324 (53.1)I am worried that undergoing testing might be inconvenient.1370 (55.0)I am worried that my testing results might be positive.1543 (61.9)I am worried that my testing results might be revealed to others (eg, family members, colleagues, classmates).17.8 (4.4)Total perceived barriers score ranging from 5 to 25, mean (SD) Self-efficacy of mpox testing (frequency of choosing agree and strongly agree), n (%) 1863 (74.7)I am confident in taking an mpox test.1627 (65.3)I think it is easy for me to take an mpox test if I want.7.9 (1.6)Total self-efficacy score ranging from 2 to 10, mean (SD) a mpox: monkeypox.b YMSM: young men who have sex with men.c MSM: men who have sex with men.

Figure 3 .
Figure 3. Behavioral intention of receiving mpox vaccination and testing in different scenarios among YMSM from 6 provinces of China in September 2022 (N=2493).mpox: monkeypox; YMSM: young men who have sex with men.

Table 1 .
Distributions of background characteristics of YMSM a from 6 provinces of China in September 2022 (N=2493).

Table 2 .
Distribution of mpox a -related knowledge and cognition of YMSM b from 6 provinces of China in September 2022 (N=2493).

Mpox knowledge (frequency of choosing the right answer), n (%) 2037
(81.7) Mpox virus can be transmitted to humans through close contact with an infected person.

Table 3 .
Behavioral intention and cognition related to mpox a vaccination among YMSM b from 6 provinces of China in September 2022 (N=2493).

Table 5 .
Geodetector analysis of driving factors of the behavioral intention of receiving mpox a vaccination and undergoing mpox testing among YMSM b from 6 provinces of China in September 2022 (N=2493).
a mpox: monkeypox.bYMSM:youngmenwhohavesex with men.cThe factor detector was used.dUppercaseletterswere used as pseudonyms of the study sites.eNotapplicable.fCNY: Chinese yuan.An exchange rate of CNY 1=US $0.14 has been applied.gMSM: men who have sex with men.hSTI: sexually transmitted infection.