Travel Vaccines Research Articles

Qdenga® - A promising dengue fever vaccine; can it be recommended to non-immune travelers?

Qdenga® has been approved by the European Medicines Agency (EMA) for individuals > 4 years of age and for use according to national recommendations. The vaccine shows high efficacy against virologically confirmed dengue and severe dengue in clinical studies on 4–16-year old's living in endemic areas. For individuals 16–60 years old only serological data exists and there is no data for individuals > 60 years. Its use as a travel vaccine is still unclear. We present the studies behind the approval and the recommendations for travelers as issued by the Swedish Society for Infectious Diseases Physicians.

5 non-COVID vaccine recommendations from ACIP

Although COVID-19 vaccination remains at the forefront, ACIP has offered guidance on MMR, pneumococcal, influenza, and travel vaccines. Here's a round-up.

The dystopian soundscape: A post COVID soundscape exploration

The pandemic has caused a huge upheaval in the global landscape. From travel restrictions, illness testing and vaccination requirements, to unrest and tensions among so many, this marks an unprecedented time. As certain states and countries enforced draconian restrictions, people have sought refuge leaving some areas and repopulating others. From a soundscape of a small city whose recent booming population since covid has found increasing tension in protests and religious demonstrations, to a large city, dealing with new growth and noise concerns from entertainment establishments, short term rentals and loud vehicles. New technology is emerging to help police some of these concerns, but is there an ethical conscience in the enforcement of these? How does our role in soundscape and acoustic design help shape the future? What does the handling of this pandemic foreshadow about similar circumstances that are to come, and what does this mean for the soundscape of the future?

International Travel Vaccine Recommendations for Children.

Children are at risk of contracting diseases while traveling internationally. Beyond the importance of receiving routine vaccinations, physicians should also discuss with parents the effectiveness of vaccination as a strategy to protect their child against disease before travel. This article (1) explores the universally recommended routine vaccines that are particularly important for children to be up to date before travel (ie, measles, mumps, rubella; hepatitis A and B; polio; meningococcal; coronavirus disease 2019 [COVID-19]; and influenza) and (2) explains the travel-specific vaccination recommendations (ie, dengue, cholera, typhoid, tick-borne encephalitis, yellow fever, Japanese encephalitis, and rabies). Physicians can encourage parents to consult the Centers for Disease Control and Prevention website for travel vaccine recommendations (https://wwwnc.cdc.gov/travel). Children must remain up to date on universally recommended vaccines and receive the appropriate vaccines before international travel to prevent serious illness and limit the spread of diseases in the United States. [Pediatr Ann. 2023;52(3):e106-e113.].

International travels with children

International travels with children need special planning and preparation. Besides considering general aspects, such as the age of the child, physical fitness, pre-existing illnesses, type and extent of the journey, climatic conditions at the destination and previous travel experiences, it is important to discuss relevant travel-associated risks in the context of travel consulting. This includes extensive advice concerning mosquito protection and malaria prophylaxis and counselling and implementation of travel vaccinations. Depending on the situation of the family, an individualized travel concept can be prepared, creating the foundation for a possible problem-free international travel.

Recommended Adult Immunization Schedule, United States, 2023.

Recommended Adult Immunization Schedule, United States, 2023.

Movement restrictions, vaccine coverage, and reduction of the COVID-19 incidence rate in the fourth wave of the pandemic: Analysis results from 63 provinces in Vietnam.

On April 27, 2021, the fourth wave of the coronavirus disease 2019 (COVID-19) pandemic originating from the Delta variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began in Vietnam. The adoption of travel restrictions, coupled with rapid vaccination and mask-wearing, is a global strategy to prevent the spread of COVID-19. Although trade-off between health and economic development are unavoidable in this situation, little evidence that is specific to Vietnam in terms of movement restrictions, vaccine coverage, and real-time COVID-19 cases is available. Our research question is whether travel restrictions and vaccine coverage are related to changes in the incidence of COVID-19 in each province in Vietnam. We used Google's Global Mobility Data Source, which reports different mobility types, along with reports of vaccine coverage and COVID-19 cases retrieved from publicly and freely available datasets, for this research. Starting from the 50th case per province and incorporating a 14-day period to account for exposure and illness, we examined the association between changes in mobility (from day 27 to 04-03/11/2021) and the ratio of the number of new confirmed cases on a given day to the total number of cases in the past 14 days of indexing (the potentially contagious group in the population) per million population by making use of LOESS regression and logit regression. In two-thirds of the surveyed provinces, a reduction of up to 40% in commuting movement (to the workplace, transit stations, grocery stores, and entertainment venues) was related to a reduction in the number of cases, especially in the early stages of the pandemic. Once both movement and disease prevalence had been mitigated, further restrictions offered little additional benefit. These results indicate the importance of early and decisive actions during the pandemic.

Holestatski virusni hepatitis A praćen upornim svrabom koji je uspešno lečen kombinacijom sistema za recirkulaciju molekularnih adsorbenata i kortikosteroida - prikaz slučaja

Introduction. Hepatitis A virus is a major cause of acute viral hepatitis worldwide, with approximately 1.5 million cases annually. Clinical manifestations of the hepatitis A virus infection range from asymptomatic to acute liver failure. Cholestatic viral hepatitis A is a rare clinical manifestation characterized by a prolonged course, refractory pruritus, imminent acute liver failure and generally good prognosis. The treatment of pruritus in cholestatic viral hepatitis A can be challenging because a response to conventional therapy is limited. Case report. We present the effects of a combination of pulse doses of prednisolone and two cycles of MARS (Molecular Adsorbent Recirculating System) in the treatment of a young female patient with cholestatic viral hepatitis A. This treatment option significantly reduced the duration of the disease and the intensity of pruritus and led to full recovery of the patient and normalization of laboratory parameters of cholestasis. Conclusion. This treatment combination has proven to have significant and lasting effects with no relapse of pruritus. Low doses of corticosteroids administered for a short time reduce the risk of side effects. The importance of vaccination of international travellers should be also pointed out here.

The global health challenge of counterfeit vaccination certificates: The case of yellow fever vaccination among travelers departing from Khartoum International Airport in Sudan

AbstractBackgroundCounterfeit travel vaccination certificates pose a significant threat to public health and compromise disease control measures. We investigated the self‐reported vaccination status, the validity of yellow fever vaccine (YFV) certificates (ICVPs), and knowledge and perception about the disease and its vaccine among Sudanese travelers departing through the Khartoum International Airport (KIA).MethodsThis was a cross‐sectional survey using a non‐probability convenience sampling technique among Sudanese travelers departing through KIA between October and November 2021. We assessed the self‐reported uptake of YFV and subsequently verified the ICVPs among those reported to be vaccinated. We also assessed participants’ knowledge about the disease in addition to their knowledge and perception of YFV.ResultsFour hundred travelers were interviewed. Most participants (88.0%) reported being vaccinated. However, two‐thirds of their ICVPs (63.0%) were counterfeit. More than one‐third of the participants (35.3%) had poor knowledge of YF and YFV. Carrying a valid ICVP was associated with participants' overall good level of knowledge about YFV (p = 0.030), knowledge about the nature of infection (p‐value = 0.008), disease transmission (p = 0.016) and prevention (p = 0.028), and countries that require a mandatory YFV proof (p = 0.005). Many participants perceived YFV as important (93.3%), safe (86.5%), and effective (82.0%).ConclusionThe proportion of counterfeit ICVPs was high. Many of the participants had a poor level of knowledge about YF and YFV. Counterfeit ICVPs have grievous implications for YF prevention and control in Sudan and other countries. There is an urgent need to revisit the implementation of the International Health Regulations in Sudan to leverage recent technological advancements in immunization information systems such as electronic certification.

A combined inactivated cholera and hepatitis A vaccine-induced potent protective immunity in a mouse model.

Cholera and hepatitis A are serious infections spread by consuming contaminated food or water. Vaccination is the most effective strategy to prevent them. Inactivated vaccines are available for both diseases. Our goal in this study is to evaluate the immunogenic response of hepatitis A and cholera combination vaccines compared to the separate vaccines. Hepatitis A and cholera vaccine formulations with and without adjuvants (alum or chitosan) were developed and injected into mice intraperitoneally. We measured the rate of seroconversion; serum-specific antibody titers; lymphoproliferation analysis; cytokine secretions for IL2, IL4, IL10, and IFN-; and a challenge test against cholera strains in the vaccinated mice. Based on the results, the combined vaccination formulation, whether adjuvanted or not, significantly boosted the immune response on both humoral and cellular levels against both hepatitis A and cholera antigens compared to the individual vaccines. These findings validated an important concept for developing an effective combined cholera and hepatitis A vaccine that could be introduced as a novel combined vaccine for travelers as part of a standard immunization schedule. KEY POINTS: • Cholera and hepatitis A combined vaccines (with or without adjuvants) were prepared. • The vaccines were injected into mice groups for humoral and cellular immunity evaluation. • Combined vaccines gave substantial protection against both immunogens.

Vaccinations in athletes

The prevention of infections is essential to athletes’ health and performance. Even mild infections can severely affect athletic performance and the eligibility to train and compete. One of the most effective means of avoiding severe infections are vaccinations. However, like the general population, athletes frequently do not receive the recommended vaccinations. This shortcoming is largely based on fear of adverse vaccine reactions, concerns about the efficacy, misinterpretations, negligence, and poor communication. As sports medicine physicians are involved in the regular screening of adolescent, adult, and senior athletes, they are in a unique position to advise on an individual basis about the risks and benefits of an athlete-specific vaccination schedule. Thus, every preparticipation physical examination should be used to check the vaccination status and, if needed, optimize and update the athletes’ vaccination profile. In this clinical review, recommendations for standard, travel, and specific-indication vaccinations in athletes will be given and their efficacy, timing, and administration in the sports context will be discussed. The review will be completed by recommended literature and useful apps for the sports medicine physician involved in the preparticipation physical examination of athletes. Key Words: Standard Vaccinations, Travel Vaccinations, Indication Vaccinations, Tetanus, Diphtheria, Pertussis, Measles, Mumps, Rubella, Hepatitis A/B, SARS-CoV-2, Influenza, Tick-Borne-Encephalitis, Sports

Temporal Trend of COVID-19 Vaccine Acceptance and Factors Influencing International Travellers.

The COVID-19 pandemic has seen disrupted international travel due to travel restrictions and public health measures aimed at containing the spread of the virus. With increasing evidence of the COVID-19 vaccines’ ability to mitigate disease severity, reopening tourism is desirable to promote the recovery of the global economy. However, the COVID-19 vaccine and vaccination passport for international travellers remains an ongoing debate. Little is known of the acceptance of these and the influencing factors among this population group. Therefore, this study sought to determine the temporal trend in COVID-19 vaccine acceptance and influencing factors among international travellers. A cross-sectional study was conducted using a self-administered questionnaire among international travellers who visited the Thai Travel Clinic, Hospital for Tropical Diseases, Mahidol University, Thailand from June 2021 to December 2021 (3 different variants dominated during this period). Study data were analyzed using SPSS software, version 23. Chi-square was used to demonstrate associations. Binary logistic regression was used to evaluate the magnitude of effect, demonstrated by odds ratio with 95% confidence interval. All significant variables were included in a multinomial logistic regression model to estimate adjusted odds ratios. The study enrolled 1068 travellers, 719 (67.3%) Thai and 349 (32.7%) foreign travellers. Most travellers were female (55.4%) and aged 18–30 years. The three main purposes for visiting the clinic were: for study, visiting friends and relatives, and returning to their home country. The overall COVID-19 vaccine acceptance rate among the travellers was 96.2%. The temporal trend of acceptance among Thai and non-Thai travelers varied from 93–99% and 93–100%, respectively. Vaccine efficacy, protective duration of the vaccine, risk of infection, and travel plan were factors strongly associated with COVID-19 vaccine acceptance. In conclusion, the COVID-19 vaccine acceptance rate among these international travellers was very high. The safe and effective reopening of tourism to international travellers will facilitate economic recovery.

Travelers and travel vaccines at six health care systems in the Vaccine Safety Datalink

BackgroundStudying the safety of travel vaccines poses challenges since recipients may be traveling during the risk window for adverse events and the identification of a suitable comparison group can also be difficult. The examination of traveler characteristics, travel vaccination patterns, and health care utilization using electronic health record (EHR) data can inform the feasibility of future travel vaccine safety studies. MethodsA retrospective cohort study of health plan members in the Vaccine Safety Datalink Project aged 9 months and older who had a travel-related encounter or received a travel vaccine from 2009 to 2018 was performed. Travel regions visited, travel duration, type of travel vaccine received (typhoid, yellow fever, Japanese encephalitis, rabies, and cholera), and timing of vaccination date before departure date were described. Sociodemographic information, clinical characteristics, and health care utilization were compared between travelers who received travel vaccines and travelers who did not. ResultsA total of 1,026,822 unique travelers departing from the United States were identified; 612,795 travelers received 898,196 doses of travel vaccines. The most commonly administered travel vaccine was typhoid vaccine and 77% of all travel vaccines were given more than one week prior to departure. Compared with travelers without travel vaccines, travelers with travel vaccines were overall similar but as a group were slightly younger, healthier, and had lower Hispanic representation. Health care utilization dramatically decreased during travel. Outpatient visits decreased from 294.8 visits per 10,000 person-days before travel to 24.2 visits per 10,000 person-days during reported travel dates. ConclusionsThrough the EHR information from almost a million travelers, a departure date and duration of travel were successfully captured for the majority of travelers with corresponding health care utilization data. Time after vaccination and prior to departure can potentially be used in the future to compare travelers who receive travel vaccines with travelers who do not receive travel vaccines when looking at adverse events of interest after vaccination.

COVID-19 Vaccine Willingness and Related Factors Among Health Care Workers in 3 Southeast Asian Jurisdictions

COVID-19 vaccine hesitancy is widespread and may lead to refusal or delay of vaccination, eventually reducing the overall vaccination coverage rate and vaccine effectiveness. Willingness to receive COVID-19 vaccination among health care workers (HCWs) is diverse across different jurisdictions. To assess the COVID-19 vaccine willingness among HCWs in 3 Southeast Asian jurisdictions in the context of pandemic severity and vaccination policy. A cross-sectional online survey was conducted among frontline HCWs in Hong Kong, Nepal, and Vietnam from May to November 2021. Eligible participants were nurses and doctors aged 18 and older, working in public or private health care settings on a full-time or part-time basis. The COVID-19 pandemic and vaccination policy. COVID-19 vaccination willingness was defined as HCW willingness toward receiving the COVID-19 vaccine in full course or the first dose of the vaccine, and willingness to take the second dose. Information on sociodemographic characteristics, the history of seasonal influenza vaccination, attitudes toward vaccination, and opinions on strategies associated with vaccination uptake from the study participants. Among the 3396 eligible doctors and nurses who participated in the survey, 2834 (83.4%) were from Hong Kong, 328 (9.7%) were from Nepal, and 234 (6.9%) were from Vietnam. Most respondents were female (76.2% [2589 ]), aged 30 to 39 years (31.2% [1058]), and nurse HCWs (77.6% [2636]); the response rates were 11% (2834 of 25 000) in Hong Kong, 36% (328 of 900) in Nepal, and 13% (234 of 1800) in Vietnam. Overall, the prevalence rate of willingness to take the COVID-19 vaccine was highest in Nepal (95.4% [313 of 328]), followed by Vietnam (90.6% [212 of 234]), and lowest in Hong Kong (54.4% [1542 of 2834]), relating to their different attitudes and opinions toward the COVID-19 vaccination, and the pandemic severity and vaccination policy in the 3 jurisdictions. Doctors were more willing to take COVID-19 vaccination than nurses (odds ratio, 5.28; 95% CI, 3.96-7.04). Older age (odds ratios, 1.39-3.70), male gender (odds ratio, 1.41; 95% CI, 1.11-1.75), higher educational level (odds ratio, 1.48; 95% CI, 1.17-1.87), and having seasonal influenza vaccination uptake history (odds ratio, 2.15; 95% CI, 1.82-2.54) were found to be associated with increased willingness. Choice of vaccination brand with adequate information, immunity passport, time off from work for vaccination and subsidy for travel to inconvenient vaccination centers were considered as strategies to enhance vaccine willingness. In this survey study, vaccination unwillingness existed among HCWs in Southeast Asian regions, especially in Hong Kong. The findings of this study may have utility in the formulation of vaccination promotion strategies such as vaccination incentives. Attitudes toward vaccination in HCWs might be examples for the general population; however, changes over time should be further investigated.

An Erudition and Attitude of Dental students and Dental practitioners on Travel Vaccines

Objective: With the rise in travel among the current age, there is a greater chance of infectious disease spreading across the country being visited as well as the country to which the traveler belongs. Through their travel habits and behaviors, travelers play a key influence in the spread of infectious diseases across international borders. Aim: This study was conducted with a aim to assess the knowledge, attitude and practices regarding travel vaccine among dental students and dental practitioners in and around Kanpur city.
 Materials and Methods: A cross-sectional study was conducted at a private dental college, in Kanpur from December 2021 to March2022 0using quantitative method of data collection among total of 450 dental student and dental practitioners.
 Result: A total of 190 (42.2%) males and 260 (57.7%) female respondents participated in the study, out of which 130(28.8 %) participants were married and 320 (71.1 %) were single. 15.5 % of the respondents were aware of the concept of travel vaccines while 6.67 % of the respondents could give correct definition of travel vaccine. Knowledge regarding travel vaccine was found to have improved the uptake of travel vaccine (P = 0.02).
 Conclusion: The study shows that as the knowledge improves the uptake of travel vaccine increases significantly.

Important arboviral diseases in returning travelers: dengue, chikungunya and zika

Arboviral infections are an important differential diagnosis in returning travelers with fever, muscle or joint pain and rash. Arboviruses have spread widely around the globe in the last decades. The most common arboviral infections in returning travelers from tropical and subtropical areas are dengue, chikungunya and zika. Their most important vectors, Aedes (Stegomyia) mosquito species, have adapted to the urban environment, which enabled arboviruses to establish urban transmission cycles. Population growth, urbanization, globalization, modern means of transportation and global warming are speeding up their spread.Laboratory confirmation of an arboviral infection can generally be obtained by direct virus detection (PCR, antigen test) in the first week of illness; from the second week of illness serology can be used. Treatment is mostly symptomatic.Dengue fever is the most common cause of fever in returning travelers from South-East Asia. Patients have to be educated about and observed for warning signs of severe dengue that can rarely develop around day 5 of the disease and is marked by a rise in hematocrit.Chikungunya mostly occurs in epidemics and is characterized by severe and often long-lasting arthritis.Preconceptional screening for zika virus infection is not recommended. Instead, travelers should delay conception for up to three months after returning from a zika endemic area.Dengue, chikungunya and zika vaccine development has been hampered by difficulties, for example antibody-dependent-enhancement or the unpredictability of outbreaks, and up to now no vaccines for travelers have been licensed. Yet several promising vaccine candidates are currently under development.

Baby on board - recommendations for pediatric travel consultation

Traveling with babies and children is challenging for parents and the doctor providing travel medicine advice. Especially pediatric VFR (visiting friends and relatives) travelers have a higher risk for infectious diseases due to lower risk perception and higher exposure. Being well prepared helps in exploring the world while staying healthy. Topics to be discussed in pediatric travel consultation are travel vaccinations, mosquito repellents, malaria prophylaxis, thorough sun protection, rehydration for gastroentritis, avoidance of rabies exposure, an agetailored travel pharmacy and more. We provide a guide to the most important topics for pediatric travel consultations.

Travel vaccines are strongly associated to reduced mortality in prostate cancer patients - a real effect or residual confounding?

Repurposing of existing drugs and vaccines for diseases that they were not originally intended for is a promising research field. Recently there has been evidence that oral cholera vaccine might be used in the treatment of inflammatory disease and some common cancers. Specifically, Ji et al showed that the administration of cholera vaccine after a prostate cancer diagnosis reduced prostate cancer specific mortality rates by almost 50%. In a cohort of men from Stockholm, Sweden, with more detailed cancer data and a higher coverage of exposure to vaccine, we replicated these findings using a marginal structural Cox model. We showed that administration of cholera vaccine after prostate cancer diagnosis is associated with a significant reduction in mortality (HR 0.46, 95% CI 0.31–0.69, p-value 0.0001) even after adjusting for all known confounders. However, the same effect (or even stronger) could be seen for several other traveling vaccines and malaria prophylaxis. Therefore, we conclude that this effect is most likely due to a healthy traveler bias and is an example of residual confounding.

Travel desire over intention in pandemic times

• Travel Intention was critically complicated by numerous factors linked to COVID-19. • We empirically validate Travel Intention, Craving and Vaccine Confidence. • Travel Intention, unlike Travel Craving, has no relationship with Vaccine Confidence. • We discuss implications for theory and marketing and communication strategies.

Public acceptability of COVID-19 control measures in Singapore, Hong Kong, and Malaysia: A cross-sectional survey

BackgroundSeveral countries have implemented control measures to limit SARS-CoV-2 spread, including digital contact tracing, digital monitoring of quarantined individuals, and testing of travelers. These raise ethical issues around privacy, personal freedoms, and equity. However, little is known regarding public acceptability of these measures. MethodsIn December 2020, we conducted a survey among 3635 respondents in Singapore, Hong Kong, and Malaysia to understand public perceptions on the acceptability of COVID-19 control measures. FindingsHong Kong respondents were much less supportive of digital contact tracing and monitoring devices than those in Malaysia and Singapore. Around three-quarters of Hong Kong respondents perceived digital contact tracing as an unreasonable restriction of individual freedom; <20% trusted that there were adequate local provisions preventing these data being used for other purposes. This was the opposite in Singapore, where nearly 3/4 of respondents agreed that there were adequate data protection rules locally. In contrast, only a minority of Hong Kong respondents viewed mandatory testing and vaccination for travelers as unreasonable infringements of privacy or freedom. Less than 2/3 of respondents in all territories were willing to be vaccinated against COVID-19, with a quarter of respondents undecided. However, support for differential travel restrictions for vaccinated and unvaccinated individuals was high in all settings. InterpretationOur findings highlight the importance of sociopolitical context in public perception of public health measures and emphasize the need to continually monitor public attitudes toward such measures to inform implementation and communication strategies.