What determines mpox vaccination uptake? Assessing the effect of intent-to-vaccinate versus other determinants among men who have sex with men

Risk factors associated with human Mpox infection: a systematic review and meta-analysis

BACKGROUND

Mpox emerged as a significant global public health concern during the 2022-2023 outbreak, impacting populations in both endemic and non-endemic countries. This study reviews and synthesises evidence on the risk factors associated with human Mpox transmission across these regions.

METHODS

A systematic search of peer-reviewed original studies was conducted across Scopus, Embase, Web of Science and PubMed databases, covering publications up to 31 March 2024. The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Two authors independently screened the articles by title, abstract and full text. The Newcastle-Ottawa Scale used to assess the risk of bias for included articles. Fixed- or random-effects meta-analysis was conducted when at least two studies reported ORs or relative risks, with 95% CIs. Heterogeneity was assessed using the [Formula: see text] statistic. This study was registered on PROSPERO (ID: CRD42023459895).

RESULTS

The systematic review identified 947 articles through database searches, of which 31 met our inclusion criteria. The meta-analysis revealed significant risk factors associated with Mpox infection. Interaction with infected animals (OR=5.61, 95% CI 2.83, 11.13), HIV infection (OR=4.46, 95% CI 3.27, 6.08), other sexually transmitted infections (OR=1.76, 95% CI 1.42, 2.19), unprotected sexual activities (OR=1.53, 95% CI 1.13, 2.07), contact with an infected person (OR=2.39, 95% CI 1.87, 3.05), identification as men who have sex with men (OR=2.18, 95% CI 1.88, 2.51) and having multiple sexual partners (OR=1.61, 95% CI 1.24, 2.09) were associated with increased Mpox infection risk. Conversely, smallpox vaccination was associated with a significantly reduced risk of Mpox infection (OR=0.24, 95% CI 0.11, 0.55).

CONCLUSION

Identification of risk factors associated with Mpox provides insights for strategic public health planning, enabling targeted interventions for high-risk groups and optimising resource allocation to strengthen Mpox control efforts.

Understanding hepatitis E vaccination intention among women of childbearing-age: A theory-based cross-sectional study

OBJECTIVES

The purpose of this study was to investigate the HEV vaccination intention, its determinants, and overall influence mechanisms among childbearing-age women.

METHOD

The current study was cross-sectional and conducted online from June 25, 2023 to September 25, 2023 in Nanjing, China. Logistic regression models were constructed to identify the intention-associated background factors. Technology Acceptance Model (TAM) and Theory of Planned Behavior (TPB) were integrated and expanded as TAM-TPB model to further investigate the determinants and overall influence mechanism of HEV vaccination intention among this population using structural equation modeling.

RESULTS

A total of 423 eligible participants were included in this study. High general HEV knowledge was independently associated with an increased intention to get HEV vaccination (OR = 1.97, 95 % CI: 1.11-3.58, P = 0.023). All the hypotheses proposed in the theoretical TAM-TPB model were supported, with perceived ease of use, perceived usefulness, attitude, subjective norm, and perceived behavioral control positively affecting the intention of HEV vaccination (all P values <0.05), while perceived risk (P = 0.003) exhibited an inverse association with HEV vaccination intention. The model achieved an acceptable fit, and the total explained variance of HEV vaccination intention was as high as 86.20 %. Moreover, no significant common method bias was observed.

CONCLUSION

This is the first theory-based study that explored the HEV vaccination intention, its determinants, and overall influence mechanism among childbearing-age women. The results of the current study are of great importance for improving the understanding of the HEV vaccination intention among females of childbearing age.

Willingness to receive mpox vaccine among men who have sex with men: a systematic review and meta-analysis

BACKGROUND

Since May 2022, mpox outbreaks have been occurring in non-mpox endemic areas, with the main population affected being men who have sex with men (MSM). Outbreak prevention and control depend not only on the effectiveness of vaccines but also on people's willingness to receive these vaccines. Currently, there is lack of synthesis on the overall rates and influence factors of MSMs' willingness to vaccinate against mpox. Therefore, we systematically reviewed studies that assessed the willingness of MSM to receive mpox vaccine.

METHODS

Studies reporting mpox vaccination intentions among MSM were included by searching five databases (PubMed, Web of Science, EMBASE, CINAHL, and SCOPUS) from inception to May 12, 2024. The quality of the included literature was assessed using Joanna Briggs Institute's critical appraisal tool. The data analysis software is Stata17. The systematic review has been registered with Prospero (registration ID: CRD42023452357).

RESULTS

Twenty cross-sectional studies were included in the review. Meta-analysis results showed that the pooled willingness rate of vaccinate against mpox was 77.0% (95% CI: 73-81%, I2 = 99.4%). According to subgroup analysis, study countries (P = 0.002), research sample size (P = 0.001), and whether participants were infected with HIV (P = 0.002) may be sources of heterogeneity. The results of the meta-analysis of influencing factors showed that more number of sexual partners (OR: 2.24, 95%CI: 1.86-2.69), pre-exposure prophylaxis use (OR: 6.04, 95%CI: 4.80-7.61), history of sexually transmitted infections (OR: 2.96, 95%CI: 2.33-3.76), confidence in the vaccine's effectiveness (OR: 2.79, 95%CI: 2.04-3.80) and safety (OR: 10.89, 95%CI: 5.22-22.72), fear of mpox infection (OR: 2.47, 95%CI: 2.11-2.89) and epidemics (OR: 2.87, 95%CI: 2.22-3.70), high mpox knowledge (OR: 2.35, 95%CI: 1.51-3.66), and the belief that people at high risk should be prioritized for vaccination (OR: 3.09, 95%CI: 1.40-6.84) were the facilitators of vaccine willingness. In addition, as a secondary outcome, meta-analysis results showed a pooled unwillingness rate of 16% (95% CI: 13-20%, I2 = 98.1%, 9 studies).

CONCLUSION

Willingness to vaccinate mpox was high among MSM, but some participants still had negative attitudes towards vaccination. Therefore, the Ministry of Public Health should develop targeted and effective strategies against those influencing factors to prevent and manage mpox outbreaks.

Monkeypox: A Viral Zoonotic Disease of Rising Global Concern

Monkeypox (mpox) is a rare viral zoonotic disease, endemic to Central and West Africa, caused by the monkeypox virus, an orthopoxvirus similar to the variola virus (smallpox). Although sporadic travel-associated cases have historically occurred outside Africa, in May 2022, mpox began spreading globally in multiple nonendemic countries across several continents. In 2024, there has been an increase in globally reported confirmed cases of mpox and deaths from mpox, making it a public health emergency of international concern. The reasons for the unusual global spread are under investigation but likely relate to increased travel and waning population immunity to orthopoxviruses. Transmission now appears to be mainly through close, intimate contact, especially among men who have sex with men. Mpox is usually a self-limited disease. Although limited approved antiviral treatments are available, such as tecovirimat, which the European Medicines Agency approved in January 2022 for the treatment of mpox, their widespread availability and effectiveness in the current outbreak remain to be investigated. Public health control measures include surveillance, case identification/isolation, contact tracing, and targeted vaccination of contacts at high risk of exposure. However, challenges remain in curtailing the current unprecedented outbreak. Critical knowledge gaps include animal reservoir(s) responsible for initial spillover events, viral mutations that may enhance transmissibility, optimal diagnostics for noninvasive specimens, effective antiviral therapies, next-generation vaccines providing longer-term immunity, and building global capacity for outbreak response. This review summarizes the current literature on mpox virology, epidemiology, pathogenesis, clinical manifestations, diagnostics, treatment, prevention, and public health control measures. Ongoing investigation and research are needed to better understand mpox’s evolving epidemiology, pathogenicity, transmissibility, and ecology to guide strategies for containing the outbreak and preventing future global emergence.