Travelers’ vaccines and their adverse events in Nara, Japan

Background: It is important to analyze the types of vaccines in travel clinics to determine the focus points in future practice. Methods We retrospectively reviewed the electronic medical records of all patients who visited the travel clinic of Nara Medical University between June 2013 and December 2019 to determine their background and the vaccines administered. The information regarding adverse events of the unapproved vaccines in Japan (Havrix®, Verorab®, Boostrix®, Priorix®, Typhim Vi®, and Mencevax®) was also collected. Results Of 645 patients, 58.6% were men and the median age was 31 years. Business was the most common travel purpose (34.9%), and Southeast Asia was the most common destination (40.2%). More than 80% of travelers to low- and middle-income countries were vaccinated against hepatitis A, while the rabies vaccination rate was approximately 50%. Typhoid vaccination coverage among travelers to South Asia was approximately 50%. The incidence of adverse events requiring medical consultation, telephonic consultation, or prolonged stay in the examination room was less than 5% for all unapproved vaccines in Japan. Conclusion More patient education is needed to increase the vaccination rate of rabies and typhoid vaccines. Adverse events to unapproved vaccines in Japan were not high and were well-tolerated.