Cholera is endemic in approximately 50 countries, primarily in Africa and South and Southeast Asia, and in these areas, it remains a disease associated with poverty. In developed nations, cholera is rare, and cases are typically imported from endemic areas by returning travellers. Cholera is readily preventable with the tools available to modern medicine. In developing nations, cholera transmission can be prevented through improved water, sanitation, and hygiene services and the use of oral cholera vaccines (OCVs). For travellers, risk can be mitigated by practicing regular hand hygiene and consuming food and water from safe sources. OCVs should be considered for high-risk travellers likely to be exposed to cholera patients or contaminated water and food. There are currently three World Health Organization pre-qualified OCVs, which are based on killed whole-cell strains of Vibrio cholerae. These established vaccines offer significant protection in adults and children for up to 2 years. A novel live attenuated vaccine that provides rapid-onset protection in adults and children is licensed in the USA and Europe only. Live attenuated OCVs may mimic the natural infection of V. cholerae more closely, generating rapid immune responses without the need for repeat dosing. These potential benefits have prompted the ongoing development of several additional live attenuated vaccines. The objective of this article is to provide a general review of the current landscape of OCVs, including a discussion of their appropriate use in international travellers.

Background: Dengue virus infection is a significant challenge for global health, with 100 million symptomatic cases, 2.3 million DALYs and 20,000 deaths annually. Dengue vaccines must provide long-lasting immunity against all four virus serotypes, especially in dengue-naïve individuals, in order to avoid the severe manifestations of secondary infections. Methods: This scoping review summarizes current evidence on licensed dengue vaccines and vaccine candidates, focusing on immunogenicity, efficacy, and safety outcomes. To identify relevant trials, in October 2023 we queried ClinicalTrials.gov using the search term “dengue vaccines” to identify past and present vaccine candidates; the search was repeated in February 2025. Vaccines were categorized into licensed (CYD-TDV and TAK-003), late-stage (TV003/TV005), and early-stage candidates (TDEN, DPIV, V180, TVDV). Results: CYD-TDV (Dengvaxia^®) showed moderate efficacy in large trials, with higher efficacy in seropositive than in seronegative individuals. Following commercialization, an increased hospitalization risk was discovered in the latter group. Due to these findings and impossibility of screening for prior exposure in endemic settings newer vaccines are now preferred and CYD-TDV production has recently been discontinued due to declining demand. TAK-003 (Qdenga^®) demonstrated high efficacy against virologically confirmed dengue (VCD) and dengue-related hospitalization. This vaccine was generally well tolerated and is currently recommended by scientific societies and national authorities for travelers and by WHO for routine use in adults and children in endemic settings. TV003 and TV005, developed by NIAID, showed strong immunogenicity and efficacy in phase II trials and human challenge models. Preliminary results show that a single-dose of TV003 has an efficacy of 79.6% in seronegatives and 89.2% in seropositives against VCD at a 2-year follow-up. Both formulations elicited tetravalent responses with an acceptable safety profile. Other vaccine strategies, including TDEN (live-attenuated), DPIV (purified inactivated), V180 (subunit), and TVDV (DNA-based) are still in early-phase development and suffer from waning antibody titers and limited efficacy in naïve subjects. Conclusions: The development of a safe and effective vaccine remains complex due to immunologic challenges. Currently, TAK-003 is regarded as the best option for broad implementation, while TV003 and TV005 remain promising candidates due to their shorter schedule and robust immunogenicity. Further research is needed to optimize vaccine strategies in seronegative populations, immunocompromised subjects, older adults, and travelers.

This paper discusses challenges in formulating and harmonizing malaria prevention recommendations for travellers. It explores diverse approaches used by advisory groups to assess malaria risk and shares insights from the 2023 International Expert Committee for Travel Medicine meeting. It also explores future prospects for enhancing malaria prevention recommendations for travellers.

The substantial number of older adults undertaking international travel has increased the relevance of pre-travel prevention in this population. However, vaccination strategies in this group require consideration of immune aging, baseline status, medication use, and travel-related exposure. This narrative review summarizes the current evidence on vaccination in senior travelers, with particular attention to the vaccines most relevant to this population, the differences in the strength of evidence across vaccines, and the clinical factors that should guide pre-travel decision-making. Routine vaccines, including influenza, COVID-19, pneumococcal, respiratory syncytial virus, herpes zoster, and tetanus-diphtheria vaccines, constitute an essential part of pre-travel assessment, whereas travel-specific vaccines, such as hepatitis A, hepatitis B, typhoid, rabies, Japanese encephalitis, tick-borne encephalitis, and cholera, should be considered according to the destination, itinerary, expected exposure, and time before departure. Yellow fever vaccination represents a particular clinical challenge because advancing age is associated with a greater risk of serious vaccine-associated adverse events, making individualized risk‒benefit assessment essential. Recently introduced dengue and chikungunya vaccines should also be considered on an individualized basis, taking into account exposure risk, potential benefits, comorbidities, and the current limitations of the available evidence. The review also highlights the importance of integrating vaccination with non-vaccine preventive strategies, including food and water precautions, vector avoidance, and hygiene measures. Although the evidence base has expanded, important uncertainties remain, particularly because age-specific data are limited and frail older adults remain underrepresented in clinical studies. Overall, pre-travel care for senior travelers should be comprehensive, exposure-based, and individualized according to the clinical profile and travel characteristics of each traveler.