BACKGROUND: Yellow fever (YF) can be prevented through vaccination, but YF vaccination causes adverse events. The increasing number of travelers to YF-endemic areas prompted an investigation of YF vaccination's adverse events on Koreans. MATERIALS AND METHODS: From January to December 2007, 318 live-17DD vaccinees at the International Travelers' Clinic of the National Medical Center were enrolled in this study. RESULTS: The adverse events were evaluated through six telephone interviews of 309 subjects (male: 168, 54.4%) on days 3, 6, 9, 16, 23, and 30 after the administration of the vaccine. There were 106 adverse events in 97 (31.4%) subjects aged 11 months to 70 years (male: 56, 18.1%). Of the 34 (11.0%) subjects who had underlying diseases, 3 (1.0%) reported adverse events (P=0.06). Nineteen (6.1%) of the 72 (23.3%) subjects who concurrently received other vaccines also experienced adverse events (P=0.29). Those who had underlying illnesses and those aged 10 to 19 years reported more frequent adverse events (P=0.06 and 0.14, respectively), but the significance of this finding is uncertain. Most of the adverse events occurred within 10 days after the vaccination and spontaneously subsided. CONCLUSION: This study shows that most of the YF vaccine's adverse events are well tolerated and that the vaccine safely protects a vaccinee from YF.
Aged ; Humans ; Interviews as Topic ; Vaccination ; Vaccines ; Yellow Fever ; Yellow Fever Vaccine

BACKGROUND: Yellow fever (YF) can be prevented through vaccination, but YF vaccination causes adverse events. The increasing number of travelers to YF-endemic areas prompted an investigation of YF vaccination's adverse events on Koreans. MATERIALS AND METHODS: From January to December 2007, 318 live-17DD vaccinees at the International Travelers' Clinic of the National Medical Center were enrolled in this study. RESULTS: The adverse events were evaluated through six telephone interviews of 309 subjects (male: 168, 54.4%) on days 3, 6, 9, 16, 23, and 30 after the administration of the vaccine. There were 106 adverse events in 97 (31.4%) subjects aged 11 months to 70 years (male: 56, 18.1%). Of the 34 (11.0%) subjects who had underlying diseases, 3 (1.0%) reported adverse events (P=0.06). Nineteen (6.1%) of the 72 (23.3%) subjects who concurrently received other vaccines also experienced adverse events (P=0.29). Those who had underlying illnesses and those aged 10 to 19 years reported more frequent adverse events (P=0.06 and 0.14, respectively), but the significance of this finding is uncertain. Most of the adverse events occurred within 10 days after the vaccination and spontaneously subsided. CONCLUSION: This study shows that most of the YF vaccine's adverse events are well tolerated and that the vaccine safely protects a vaccinee from YF.
Aged ; Humans ; Interviews as Topic ; Vaccination ; Vaccines ; Yellow Fever ; Yellow Fever Vaccine

Objective To perform quality control in live attenuated yellow fever vaccine(chicken embryo cell)virus seed bank at the genomic level using the new generation Illumina/Solexa sequencing platform.Methods The live attenuated yellow fever vaccine strain YF17D-204 was inoculated into primary chicken embryo cells,and the chicken embryo cell adapted strains of live attenuated yellow fever vaccine were screened to establish YFV17D-CEC tertiary virus seed bank. The genome RNA of virus seeds was extracted,and the RNA library was prepared. The new generation Illumina/Solexa sequencing platform was used for high-throughput RNA sequencing. The whole genome nucleic acid sequence of yellow fever virus was systematically analyzed by using biological softwares such as FastQC,Trimmomatic,SPAdes,GapFiller,PrInSeS-G,Prokka,RepeatMasker,CRT,NCBI Blast~+,KAAS,HMMER3,TMHMM,SignalP,LipoP,ProtCamp and MegAlign.Results The whole genome of YFV17D-CEC tertiary virus seed bank contained 10 862 nucleotides,including an open reading frame(ORF)from 119 to 10 354(10 236 bp),encoding 3 412 amino acids. Sequence alignment analysis showed that the sequence of YF17D-CEC tertiary virus seed bank was 100% identical with YFV17D RKI(JN628279.1),YF/Vaccine/USA/Sanofi-Pasteur-17D-204/UF795AA/YFVax(JX503529.1)and YFV17D-204(KF769015.1),and no mutation occurred in the whole genome of the tertiary virus seed bank. Comparison of the sequences of different live attenuated yellow fever vaccine strains showed that yellow fever virus had multiple polymorphic sites.Conclusion YFV17DCEC has good genetic stability in primary chicken embryo cells. High-throughput RNA sequencing technology can quickly detect the whole genome information of YF17D-CEC virus seed bank,and the sequence analysis data can be used in the gene level quality control of yellow fever vaccine virus seed banks.
High-throughput RNA sequencing ; Live attenuated yellow fever vaccine ; Gene expression ; Virus seed bank ; Quality control

PURPOSE:Yellow fever, a mosquito-borne viral hemorrhagic fever, is one of the most lethal diseases. Recently there have been an increasing number of Korean children who have travelled to yellow fever endemic zones and were administered yellow fever vaccine (YFV). Therefore, we carried out this study to provide child travelers with safety information of YFV. METHODS:This study was conducted at the International Clinic of National Medical Center in Seoul between April 2007 and June 2008 for the evaluation of adverse events of YFV. One hundred twenty- five children received YFV (17-DD) and were prospectively monitored for adverse events through telephone interviews on day 3, 6, 9, 16, 23 and 30 after vaccination. RESULTS:Adverse events were observed in 31 (24.8%) of 125 child travelers who received the YFV. The mean age was 12.5+/-5.0 years. Sixty-six of the child travelers (52.8%) were males. The common adverse events were pain in 11 (8.8%), swelling in 8 (6.4%) and redness in 7 children (5.6%) at the injection site. The systemic adverse events included mild fever in 5 (4.0%), headache in 5 (4.0%), cough in 4 (3.2%), abdominal pain in 3 (2.4 %), and vomiting in 2 children (1.6%). Most of the adverse events were detected within 7 days of administration and there were no differences in adverse events by gender or age. All travelers who had complained of symptoms improved spontaneously or following symptomatic treatment. CONCLUSION:This study showed that YFV is well-tolerated and there were no reports of severe adverse events. Studies are ongoing to clarify the cause and risk factors for rare adverse events.
Abdominal Pain ; Child ; Cough ; Fever ; Headache ; Hemorrhagic Fevers, Viral ; Humans ; Interviews as Topic ; Male ; Prospective Studies ; Risk Factors ; Vaccination ; Vomiting ; Yellow Fever ; Yellow Fever Vaccine

This report describes a case of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) that occurred after vaccination in a 23-year-old male. Seven days after vaccination, our patient presented with fever, myalgia, and nausea. The IgM enzyme-linked immunosorbent assay (ELISA) for yellow fever virus was positive. After a 24 day hospitalization, he recovered and was discharged. Yellow fever is a viral hemorrhagic febrile illness caused by a flavivirus and transmitted by mosquitoes. The clinical presentation ranges from a mild febrile illness to a serious infection, leading to hepatic and renal failure, myocardial injury, hemorrhage, and shock, with a case fatality rate of 20-30%. Because yellow fever is a potentially fatal disease, vaccination is encouraged for people traveling to high-risk areas. Although considered a safe vaccine, severe adverse reactions have been reported. In 2001, rare, but severe, acute viscerotropic disease following vaccination was first described. We report the case of a 23-year-old male with fever and hepatitis following vaccination with 17D yellow fever vaccine.
Culicidae ; Enzyme-Linked Immunosorbent Assay ; Fever ; Flavivirus ; Hemorrhage ; Hepatitis ; Hospitalization ; Humans ; Immunoglobulin M ; Male ; Nausea ; Renal Insufficiency ; Shock ; Vaccination ; Yellow Fever ; Yellow Fever Vaccine ; Yellow fever virus ; Young Adult

BACKGROUND: Pre-travel medical consultation is essential to reduce health impairment during travel. Yellow fever vaccination (YFV) is mandatory to enter some endemic countries. In this study, we evaluated the factors that affect compliance with appropriate prevention of infectious diseases in travelers who visited clinic for YFV. METHODS: For this retrospective study, chart reviews for 658 patients who visited a travel clinic for YFV before travel were conducted. The period of this study was from January 2016 to September 2018. The associations between appropriate vaccination and factors such as travel duration, destination, time of visiting clinic before departure, and purpose of travel were analyzed. RESULTS: Among 658 patients who got YFV during the study period, 344 patients (52.3%) received additional vaccination or malaria prophylaxis following a physician's recommendation. Travelers who visited the clinic more than 21 days before departure were more compliant than those who visited 14 days or fewer before departure (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.23–2.93; P = 0.004). Travelers visiting Africa were more compliant than were those traveling to South and Central America (OR, 1.97; 95% CI, 1.34–2.90; P = 0.001). Travelers in age groups of 40-49 years and over 70 years were less compliant than the 18–29 years old population (OR, 0.51; 95% CI, 0.28–0.93; P = 0.027 and OR, 0.19; 95% CI, 0.04–0.84; P = 0.03, respectively). Also, those who traveled for tour or to visit friends or relatives were more compliant than those who departed for business (OR, 0.77; 95% CI, 1.03–3.56; P = 0.04). CONCLUSION: For appropriate vaccination, pre-travel consultation at least 3 weeks before departure is crucial. Travelers should be aware of required vaccination and malaria prophylaxis before visiting South and Central America and Asia. Plans to enhance compliance of the elderly and business travelers should be contrived.
Africa ; Aged ; Asia ; Central America ; Commerce ; Communicable Diseases ; Compliance ; Friends ; Humans ; Malaria ; Patient Compliance ; Retrospective Studies ; Travel Medicine ; Vaccination ; Yellow Fever ; Yellow Fever Vaccine

In 2006, the annual number of Koreans traveling internationally increased to 11 million. With this increased number of Koreans traveling to developing countries, various infectious diseases have been reported to be imported into Korea. Immunization is an important tool for the prevention of such diseases. Vaccination offered to international travelers is divided into 3 categories, i.e., obligatory vaccination, vaccines against diseases with an increased risk in developing countries, and routine vaccination. Vaccination that is obligatory for travelers includes yellow fever vaccine for travelers entering yellow fever-endemic areas and meningococcal vaccination for pilgrims traveling to Saudi Arabia. Recent reports of the adverse event following yellow fever vaccination, i.e., vaccine-associated viscerotropic disease, pose a caution in the administration of yellow fever vaccine to the elderly or individuals with thymic diseases. Protein-conjugated meningococcal vaccines are generally preferred; however, polysaccharide vaccines are also effective in short-term travelers. The vaccinations recommended for the health of travelers include administration of hepatitis A (HAV), meningococcal, typhoid, rabies, tick-borne encephalitis, and plague vaccines. As many young Korean adults lack immunity against hepatitis A, the administration of the HAV vaccine is recommended for all Korean individuals in their 20s and all Korean seronegative individuals in their 30s. The risk of acquiring typhoid fever is high among travelers traveling to the rural areas of developing countries for 2 weeks or more. The rabies vaccine may be recommended for travelers traveling for longer than 3 months and animal handlers. Both tick-borne encephalitis and plague are rarely encountered among Korean travelers; furthermore, vaccines for these diseases are not available in Korea. As Japanese encephalitis is endemic in Korea, vaccination against encephalitis is not essential for Korean adults. Pre-travel counseling is an important opportunity for catch-up vaccination of healthy travelers who missed routine vaccinations.
Adult ; Aged ; Animals ; Communicable Diseases ; Counseling ; Developing Countries ; Encephalitis ; Encephalitis, Japanese ; Encephalitis, Tick-Borne ; Hepatitis A ; Humans ; Immunization ; Korea ; Meningococcal Vaccines ; Plague ; Rabies ; Rabies Vaccines ; Saudi Arabia ; Typhoid Fever ; Vaccination ; Vaccines ; Whooping Cough ; Yellow Fever ; Yellow Fever Vaccine

BACKGROUND: Travel-related risks for infectious diseases vary depending on travel patterns such as purpose, destination, and duration. In this study, we describe the patterns of travel and prescription of vaccines as well as malaria prophylaxis medication (MPM) at a travel clinic in South Korea to identify the gaps to fill for the optimization of pre-travel consultation. MATERIALS AND METHODS: A cohort of travel clinic visitors in 2011 was constructed and early one-third of the visitors of each month were reviewed. During the study period, 10,009 visited the travel clinic and a retrospective chart review was performed for 3,332 cases for analysis of travel patterns and prescriptions. RESULTS: People receiving yellow fever vaccine (YFV) (n = 2,933) were traveling more frequently for business and tourism and less frequently for providing non-medical service or research/education compared to the 399 people who did not receive the YFV. Overall, most people were traveling to Eastern Africa, South America, and Western Africa, while South-Eastern Asia was the most common destination for the non-YFV group. Besides YFV, the typhoid vaccine was the most commonly prescribed (54.2%), while hepatitis A presented the highest coverage (74.7%) considering the natural immunity, prior and current vaccination history. Additionally, 402 (82.5%) individuals received a prescription for MPM among the 487 individuals travelling to areas with high-risk of malaria infection. Age over 55 was independently associated with receiving MPM prescription, while purpose of providing service and travel duration over 10 days were associated with no MPM prescription, despite travelling to high-risk areas. CONCLUSION: Eastern Africa and South America were common travel destinations among the visitors to a travel clinic for YFV, and most of them were travelling for tourism and business. For the individuals who are traveling to areas with high-risk for malaria, more proactive approach might be required in case of younger age travelers, longer duration, and travel purpose of providing service to minimize the risk of malaria infection.
Africa, Eastern ; Africa, Western ; Antibiotic Prophylaxis ; Asia ; Cohort Studies ; Commerce ; Communicable Diseases ; Hepatitis A ; Immunity, Innate ; Korea* ; Malaria ; Prescriptions* ; Retrospective Studies ; South America ; Travel Medicine ; Typhoid-Paratyphoid Vaccines ; Vaccination* ; Vaccines ; Yellow Fever Vaccine ; Yellow Fever*