Immunizations.

Vaccinations are a cornerstone of the pretravel consultation. The pretravel provider should assess a traveler's past medical history, planned itinerary, activities, mode of travel, and duration of stay and make appropriate vaccine recommendations. Given that domestic vaccine-preventable illnesses are more common in international travelers than are exotic or low-income nation-associated vaccine-preventable illnesses, clinicians should first ensure that travelers are current regarding routine immunizations. Additional immunizations may be indicated in some travelers. Familiarity with geographic distribution and seasonality of infectious diseases is essential. Clinicians should be cognizant of which vaccines are live, as there exist contraindications for live vaccines.

United States epidemiology of hepatitis A: influenced by immigrants visiting friends and relatives in Mexico?

Among the industrialized nations, the United States annually receives the greatest number of immigrants as permanent residents. Immigrants from Mexico have represented the largest segment of the foreign-born population in recent decades, and continued growth of Mexican immigration is predicted for the decades ahead. The changing demographics of this population, including the emergence of new immigrant growth centers, will influence the future epidemiology of hepatitis A virus transmission in the United States. Travel home to the place of origin to visit friends and relatives (VFR) by both newly arrived and established Mexican immigrants constitutes a new group of travelers that now include intergenerational family units. Asymptomatic pediatric travelers-who acquire hepatitis A abroad and are infectious on return to American communities-contribute to the silent transmission of hepatitis A to playmates, caretakers, and contacts in households, daycare facilities, and elementary schools. Considering the expanded geographic distribution of Mexican immigrant settlement, the predicted increased diversity of pediatric populations in the United States over time, and the continued growth of VFR travel, a universal pediatric vaccine recommendation for hepatitis A immunization can help to prevent hepatitis A transmission in this country in the future.

An open randomized study of inactivated hepatitis A vaccine administered concomitantly with typhoid fever and yellow fever vaccines.

BACKGROUND: Concomitant administration of several vaccines is a common practice when travel clinics prepare persons for international travel. The purpose of the study was to compare the immunogenicity and safety of hepatitis A, typhoid fever, and yellow fever vaccines administered concomitantly with hepatitis A vaccine administered alone and typhoid fever and yellow fever vaccines administered alone. METHODS: Healthy adults 18 to 55 years of age were randomized to receive either VAQTA, TyphimVi, and YF-VAX on day 0 and VAQTA at week 24 (Group 1); TyphimVi and YF-VAX on day 0 and an optional dose of VAQTA 1 month later (Group 2); or VAQTA at day 0 and week 24 (Group 3). RESULTS: From March to December 1997, a total of 240 subjects were enrolled, 80 in each treatment group. Most were female and Caucasian, and the mean age was 29.4 years. Four weeks after vaccine dose 1, seroconversion to protective antibody levels against hepatitis A was 95.9% in Group 1 and 100% in Group 3. In Group 1, 93.4% of subjects demonstrated at least a 4-fold rise in neutralizing antibody levels against typhoid, compared with 90% in Group 2. Serum neutralizing antibody against yellow fever developed in 98.6% of subjects in Group 1 compared with 100% in Group 2. CONCLUSIONS: These findings were consistent with similarity in the immune responses between treatment groups as defined a priori. The adverse experience (AE) profile did not appear to be substantially affected by concomitant administration of all three vaccines. Providing these three vaccines concomitantly can simplify the process of obtaining pretravel prophylaxis and may help ensure that all needed vaccines are administered.