Present situation and challenges of vaccinations for overseas travelers from Japan

Concerns about vaccines and vaccination behavior among Japanese budget travelers to India

BACKGROUND

Low vaccination coverage among travelers poses a critical challenge to global health security. Indeed, public concerns regarding vaccines can lead to vaccine reluctance and refusal, but evidence about the impacts of concerns regarding vaccines on the uptake of travel vaccinations remains sparse. We examined the associations between concerns about vaccines and vaccination behavior among travelers.

METHODS

Japanese travelers aged 18 years or older, who stayed at a guesthouse in New Delhi, India, were targeted (n = 153). We conducted cross-sectional surveys from August 23 to September 2, 2019, and from February 19 to March 5, 2020. We examined the associations of three concerns regarding vaccines (5-point scale)-serious side effects from vaccines, vaccine safety, and vaccine effectiveness-with the uptake of travel vaccinations.

RESULTS

In total, 60 participants (39.2 %) had been vaccinated for this or a past trip. After adjusting for all potential confounding variables, concerns about serious side effects from vaccines and vaccine safety were negatively associated with the uptake of travel vaccinations. The ORs (95 % CIs) for 1-point increases in concerns about serious side effects from vaccines and vaccine safety were 0.72 (0.52, 0.99) and 0.71 (0.52, 0.96), respectively. Sensitivity analyses did not change the results substantially.

CONCLUSIONS

Concerns about vaccine safety issues were negatively associated with the uptake of travel vaccinations among the participants, with no corresponding association observed for vaccine effectiveness. Addressing concerns about vaccine safety issues, rather than vaccine effectiveness may contribute to an increased uptake of travel vaccinations.

Understanding the travel decision-making processes of COVID-19-vaccinated South Korean travelers

During the COVID-19 pandemic, many countries allowed only the vaccinated to travel abroad, and some still continue with these restrictions. This study aimed to determine the factors associated with the intention to travel abroad during this pandemic. An online survey was conducted with 270 vaccinated Korean participants. The theoretical framework of the extended goal-directed behavior model was used to predict the overseas travel intentions of tourists in the COVID-19 environment. The data were examined using frequency analysis, confirmatory factor analysis, correlation analysis, and path analysis using CB-SEM. The results show, first, that attitude, expected positive emotions, and expected negative emotions are positively correlated with desire. Second, desire and prior knowledge are positively correlated with behavioral intentions. Thus, attitude toward COVID-19 and expected emotions significantly influenced desire, and prior knowledge influenced travelers' behavioral intentions during the pandemic. The findings suggest that travelers' attitudes and emotions during the pandemic reflect their desire to travel abroad and to do so with prior knowledge. Therefore, to help potential overseas tourists meet their basic needs for personal quarantine security during travel, travel industry staff should provide personalized security services. Airlines and the tourism industry should continue to provide hand sanitizers and personal hygiene products at airports and tourist attractions to make the travel experience relatively safer for tourists. In addition, the tourism industry should introduce a campaign on safe quarantine and health to give a positive impression to potential tourists, planning their next trip. The study identifies changing travel trends, provides a foundation for safe travel experiences, and can help develop policies to improve future international travel.

Health risk management behaviors and related factors among Japanese university students participating in short-term study abroad programs

BACKGROUND

Overseas travelers should prepare for health problems at their destinations prior to travel. No prospective studies have evaluated factors related to health risk management behaviors among overseas travelers, specifically young travelers.

METHODS

We prospectively collected data from pre- and post-travel questionnaire surveys, targeting students of a university in Japan who participated in short-term study abroad programs (n = 532, 6 to 38 travel days and 11 countries). We examined health information collection, receipt of travel vaccinations for the programs and medical kit preparation as health risk management behavior outcomes and their related factors among the participants (82.7% follow-up rate).

RESULTS

In total, 17.5%, 8.0% (28.6% in Southeast Asia) and 68.9% of participants, respectively, collected travel health information via the Japanese or foreign official websites, received travel vaccinations and carried commonly used medicines. Female, travel experience to study destination, parental medical occupation and presence of illness in treatment were positively associated with the health risk management behaviors after adjusting for the covariates including study destination. For example, the adjusted odds ratio (OR) (95% confidence interval [CI]) of receiving travel vaccinations was 4.16 (1.70-10.2) for parental medical occupation relative to non-medical occupation. The adjusted OR (95% CI) of collecting travel health information was 2.54 (1.04-6.21) for travel experience to study destination relative to no overseas travel experience.

CONCLUSIONS

Personal characteristics including overseas travel experience and parental occupation provide a useful insight into approaches to promoting health risk management among university students traveling abroad.

A Safety and Immunogenicity Study of a Single Dose of a Meningococcal (Groups A, C, W, and Y) Polysaccharide Diphtheria Toxoid Conjugate Vaccine (MEN-ACWY-D) in Healthy Japanese Participants

Meningococcal disease can cause significant disability and mortality. The quadrivalent meningococcal polysaccharide diphtheria toxoid conjugate vaccine (Men-ACWY-D) protects against invasive meningococcal disease caused by serogroups A, C, W, and Y. This phase III, open-label, single-arm, multicenter study evaluated the safety and immunogenicity of a single vaccine dose in healthy Japanese adults. The study enrolled 200 participants between 2 and 55 years of age. Immunogenicity was assessed by quantifying the seroprotection rates (the proportion of participants with antibody titers ≥ 1:128 against the capsular polysaccharide from all 4 serogroups measured 28 days after vaccination). Safety endpoints included occurrence, nature, time to onset, duration, intensity, relationship to vaccination, and outcome of solicited and unsolicited adverse events (AEs) and serious AEs (SAEs). Participants included 194 adults, 2 adolescents, and 4 children. Among adults, the seroprotection rates for serogroups A, C, W, and Y were 91.2%, 80.2%, 89.1%, and 93.8%, respectively. Seroconversion rates (the proportion of participants with pre-vaccination titers of < 1:4 and a ≥ 4-fold rise from baseline) were 87.3%, 83.0%, 94.4%, and 96.4%, respectively. No immediate AEs, adverse reactions, SAEs, or deaths were reported for any age group. Men-ACWY-D is well tolerated and immunogenic, eliciting antibodies against capsular polysaccharides from all 4 serogroups in Japanese adults.

Typhoid Vaccination among Japanese Travelers to South Asia and the Factors Associated with Compliance

Objective In 2010, candid advice concerning the low rate of typhoid vaccination among Japanese travelers was received from Nepal. Recently, progressive Japanese travel clinics have encouraged Japanese travelers to be vaccinated against typhoid fever in conjunction with officially approved vaccines, such as hepatitis A vaccine. We herein report the status of typhoid vaccinations for Japanese travelers to the most endemic area (South Asia) and describe the factors associated with compliance. Methods In the travel clinic at Kurume University Hospital, we used the following criteria to retrospectively extract the records of new pre-travel Japanese clients between January 2011 and March 2015: hepatitis A vaccine administered, traveling to South Asian countries, and ≥2 years of age. We first summarized the participants and then divided them into typhoid-vaccinated and typhoid non-vaccinated groups for a comparative analysis. Results This study included 160 clients. A majority (70.0%) of these clients traveled for business. The duration of trips was long (≥1 month) (75.0%), and India was a popular destination (90.6%). A comparative study between the vaccinated group (n=122) and the non-vaccinated group (n=38) revealed that the two factors most positively associated with typhoid vaccination were business trips [adjusted odds ratio (aOR) 3.59, 95% confidence interval (CI) 1.42-9.06] and coverage by a company/organization payment plan (aOR 7.14, 95% CI 2.67-20.3). Conclusion The trend toward typhoid vaccination among Japanese travelers to South Asia with pre-travel consultation is correlated with business trips and coverage by a company/organization payment plan. If problems concerning the cost of vaccines were resolved, more travelers would request typhoid vaccination.

Characteristics of health problems in returned overseas travelers at a tertiary teaching hospital in a suburban area in Japan

Few studies have analyzed the characteristics of patients who develop physical disorders after overseas travel. We retrospectively reviewed the medical records of 183 patients who visited Nara Medical University Hospital from 2008 to 2016 because of physical problems after traveling abroad. The main travel destinations were Southeast Asia (n = 100), Africa (n = 27), and South Asia (n = 23). The main reasons for the travel were leisure (n = 96), business (n = 51), and volunteer work (n = 19). The most common final diagnosis was gastrointestinal disease (n = 72), followed by febrile disease (n = 59) and respiratory disease (n = 19). There were eight malaria cases, including one patient who was infected after <14 days of overseas travel. Additionally, 61 of 71 cases of travelers' diarrhea and 15 of 21 cases of dengue fever occurred after <14 days travel. 26 cases of vaccine preventable diseases, such as hepatitis A, typhoid fever, and influenza, were observed. Consequently, healthcare providers should notify Japanese overseas travelers that there is a non-negligible health risk inherent to short-term travel, while stressing on the importance of pre-travel medical consultation.

Hepatitis B Vaccination Status among Japanese Travelers

This study clarified the characteristics of travelers who received hepatitis B vaccinations. Subjects were 233 Japanese travelers who visited our clinic prior to travel. We summarized the characteristics of the clients and performed two comparative studies: first, we compared a hepatitis B-vaccinated group with an unvaccinated group; second, we compared a group that had completed the hepatitis B vaccine series with a group that did not complete the series. The hepatitis B vaccine was administered to 152 clients. Factors positively associated with the hepatitis B vaccination (after adjusting for age and sex) included the following: travel for business or travel as an accompanying family member; travel to Asia; travel for a duration of a month or more; and, inclusion of the vaccine in a company or organization's payment plan. Meanwhile, factors negatively associated with the vaccination were travel for leisure or education, and travel to North America or Africa. Among 89 record-confirmed cases, only 53 completed 3 doses. The completion rate was negatively associated with the scheduled duration of travel if it was from a month to less than a year (after adjusting for age and sex). The present study provides a basis for promoting vaccination compliance more vigorously among Japanese adults.

The Global Meningococcal Initiative: global epidemiology, the impact of vaccines on meningococcal disease and the importance of herd protection

INTRODUCTION

The 2015 Global Meningococcal Initiative (GMI) meeting discussed the global importance of meningococcal disease (MD) and its continually changing epidemiology. Areas covered: Although recent vaccination programs have been successful in reducing incidence in many countries (e.g. Neisseria meningitidis serogroup [Men]C in Brazil, MenA in the African meningitis belt), new clones have emerged, causing outbreaks (e.g. MenW in South America, MenC in Nigeria and Niger). The importance of herd protection was highlighted, emphasizing the need for high vaccination uptake among those with the highest carriage rates, as was the need for boosters to maintain individual and herd protection following decline of immune response after primary immunization. Expert commentary: The GMI Global Recommendations for Meningococcal Disease were updated to include a recommendation to enable access to whole-genome sequencing as for surveillance, guidance on strain typing to guide use of subcapsular vaccines, and recognition of the importance of advocacy and awareness campaigns.

Hepatitis B vaccination for international travelers to Asia

There is a wide range in prevalence of hepatitis B virus (HBV) infection and HBV immunization programs between different regions. Hepatitis B is a vaccine preventable disease yet is still endemic in the majority of countries in Asia. Despite the decreasing global prevalence of chronic HBV infection, there is still considerable risk of HBV infection among international travelers to high endemic areas. Numbers of international travelers are expected to increase year by year; thus immunization among this cohort is a crucial preventive measure. Among international travelers to Asia, HBV immunization should be recommended for those without previous HBV vaccination who plan to travel to countries with intermediate to high prevalence of HBV, and especially for those individuals at greater risk of HBV infection; including travelers engaging in casual sex, getting a tattoo or piercing, and those having dental surgery or other medical procedures. Longer duration of travel is also associated with a greater risk of HBV infection. Travelers from low HBV prevalence countries, especially those born before implementation of universal HBV vaccination, might benefit from HBV vaccination during long-term traveling to HBV intermediate to high endemic country.