Vaccinations for the Pediatric Traveler

A pilot study showing differences in glycosylation patterns of IgG subclasses induced by pneumococcal, meningococcal, and two types of influenza vaccines

The presence of a carbohydrate moiety on asparagine 297 in the Fc part of an IgG molecule is essential for its effector functions and thus influences its vaccine protective effect. Detailed structural carbohydrate analysis of vaccine induced IgGs is therefore of interest as this knowledge can prove valuable in vaccine research and design and when optimizing vaccine schedules. In order to better understand and exploit the protective potential of IgG antibodies, we carried out a pilot study; collecting serum or plasma from volunteers receiving different vaccines and determining the IgG subclass glycosylation patterns against specific vaccine antigens at different time points using LC-ESI-MS analysis. The four vaccines included a pneumococcal capsule polysaccharide vaccine, a meningococcal outer membrane vesicle vaccine, a seasonal influenza vaccine, and a pandemic influenza vaccine. The number of volunteers was limited, but the results following immunization indicated that the IgG subclass which dominated the response showed increased galactose and the level of sialic acid increased with time for most vaccinees. Fucose levels increased for some vaccinees but in general stayed relatively unaltered. The total background IgG glycosylation analyzed in parallel varied little with time and hence the changes seen were likely to be caused by vaccination. The presence of an adjuvant in the pandemic influenza vaccine seemed to produce simpler and less varied glycoforms compared to the adjuvant-free seasonal influenza vaccine. This pilot study demonstrates that detailed IgG glycosylation pattern analysis might be a necessary step in addition to biological testing for optimizing vaccine development and strategies.

Epidemiology and prevention of hepatitis A in travelers

BACKGROUND

Hepatitis A is the second most common vaccine-preventable travel-associated infectious disease and hepatitis A virus (HAV) is the most common cause of viral hepatitis. The incidence of infection is closely related to sanitary conditions and the level of economic development.

METHODS

We evaluated HAV incidence, infection-related risk factors, and HAV vaccination rates in international travelers through retrospective analyses using major databases, such as CENTRAL, MEDLINE, EMBASE, and the current literature describing epidemiological data for HAV infection in recent years.

RESULTS AND CONCLUSIONS

We found that the incidence of HAV infection in developed countries is very low. As international travel increases, the incidence of hepatitis A among travelers remains high and likely leads to regional outbreaks. Travelers should visit the Centers for Disease Control and Prevention website or Infectious Disease Prevention Center of their countries to learn about the incidence of infectious diseases associated with their destination before going abroad to determine if they should be vaccinated.

Advice for families traveling to developing countries with young children

Young children are most likely to travel to developing countries with their parents to visit relatives. Preparation for such travel must include careful counseling and optimal use of preventive vaccines and chemoprophylaxis. For infants and very young children, data defining safety and efficacy of these agents are often limited. However, accumulated experience suggests that young travelers may be managed similarly to older children and adults.

Epidemiology of Japanese encephalitis in South Korea, 2007-2010

BACKGROUND

Japanese encephalitis (JE) was the leading cause of viral encephalitis among children in South Korea in the 20(th) century. This study summarizes recent changes in the epidemiology of JE following the implementation of a vigorous immunization program in the country.

METHODS

Epidemiological investigations were performed for all reported laboratory-confirmed JE cases, and the cumulative incidence was calculated for the surveillance years 2007-2010.

RESULTS

During the surveillance period, 45 cases of JE were confirmed in the country, resulting in a cumulative incidence of 0.013-0.055 cases per 100 000 population. The median age of cases was 49.4 years, and by age group, 44.4% were aged 40-49 years. Just under a quarter (22.2%) of the cases were found to live close to a pigsty, while 42.2% of the cases were found to reside in the metropolitan areas of Seoul, Incheon, and Gyeonggi-do. None of the cases had a history of vaccination.

CONCLUSIONS

Although JE has traditionally been regarded as a children's disease, the majority of cases now occur in adults in countries where strong immunization programs exist, such as in South Korea. Consideration should be given to an adult vaccination policy in the near future.

The rhesus macaque pediatric SIV infection model - a valuable tool in understanding infant HIV-1 pathogenesis and for designing pediatric HIV-1 prevention strategies

Worldwide, the AIDS pandemic continues almost relentlessly. Women are now representing the fastest growing group of newly infected HIV-1 infected patients. The risk of mother-to-child-transmission (MTCT) of HIV-1 increases proportionally as many of these women are of childbearing age. The screening of pregnant women, the early diagnosis of HIV-1 infection, and the administration of antiretroviral therapy (ART) have helped to reduce MTCT significantly. However, this holds true only for developed countries. In many resource-poor countries, access to ART is limited, and breastfeeding, a major route of HIV-1 transmission, is essential to protect the infant from other infectious diseases preponderant in those geographic regions. HIV-1 infected children, in contrast to adult patients, have higher levels of virus replication that decline only slowly, and a subset progresses to AIDS within the first two years. Thus, it is imperative to understand pediatric HIV-1 pathogenesis to design effective prevention strategies and/or a successful pediatric HIV-1 vaccine. The review summarizes how MTCT of HIV-1 in humans can be modeled in the infant macaque model of SIV infection. Importantly, the infant macaque model of SIV infection provides the opportunity to study early virus-host interactions in multiple anatomic compartments. Furthermore, the review underlines the importance of evaluating SIV/HIV immune responses in the context of the normal developmental changes the immune system undergoes in the newborn. Thus, the pediatric SIV infection model provides a unique resource for preclinical studies of novel intervention therapies and vaccine strategies to stop MTCT of HIV-1.

Vaccinations de l'enfant voyageur

Each year, half a million of children leave France to travel towards countries south or east of the European Union, sometimes in poor sanitary conditions. In order to propose essential or useful immunizations for these trips, the current synthesis will allow the practitioner to insure that the routine French immunization schedule has been followed, and to complete it if needed, to protect the child according to the epidemiological situation in the visited area, to try to reduce the limitations of the immunization of the traveler child. In case of emergency, or close departure, it may be useful to follow an accelerated schedule of the last minute, and, sometimes, to immunize traveler children with a chronic disease. Informations on Internet sites useful for the knowledge of current infectious risks in the destination country are also provided.

[Hepatitis A acquired from an asymptomatic adopted child]

We report the case of acute hepatitis in a 36-year-old woman that was acquired from an adopted African child with asymptomatic active infection. At present, most experts do not screen for hepatitis A. However, adoptive parents should be vaccinated against hepatitis A because of the risk of unrecognized active infection in adopted children from countries in which infection is endemic.

Recomendaciones al viajero en situaciones especiales

The increase in the hope and quality of life, along with the greater rapidity and comfort of the different means of transport have made possible that travellers with chronic diseases, pregnant and kids makes tourist trips to tropical or subtropical zones. On the other hand the increase of the international cooperation has caused the appearance of long stay travellers who live in conditions such as the local population. These travellers have special characteristics due to their physical training conditions, chronic treatments, or the way of life during the travel that them makes more susceptible to suffer problems of health during the travel. For this reason the usual recommendations for travellers are insufficient in these groups and is necessary to make an individualized travel advice that considers these factors. This revision shows the most important warnings that must be made in these groups of special travellers.

Prevention of travel-related infectious diseases in families of internationally adopted children

Pretravel consultation before international adoption must encompass standard advice for those who travel, advice for those who are exposed to the newly adopted child, and information about caring for a new child during travel. Children who travel to meet siblings may need special accommodations before and during travel. Data on the health of internationally adopted children illustrate the risk of exposing family members and close contacts to some infectious diseases during or after international adoption. Parents, family members, and close contacts of the newly adopted child should be given advice to reduce their own and their child's risk. Targeted preadoption counseling, close attention to hygiene and safety advice, and prompt identification and treatment of infections lead to the safest and most trouble-free adoption travel experience.

Challenging scenarios in a travel clinic: advising the complex traveler

With adequate preparation and in consultation with a travel medicine expert, most travelers today can travel safely regardless of their age and health status. The few instances when it is prudent to alter travel plans or postpone travel altogether are not to be taken lightly. For the most part, however, most complex travelers can enjoy a healthy and rewarding travel experience.

"I hate needles" and other factors impacting on travel vaccine uptake

Travel vaccines comprise an essential component of pretravel health advice; however, many travelers do not take advantage of this preventive health strategy to decrease their risk of travel-related illness. Factors that impact on a traveler's decision on whether or not to be vaccinated are related to the knowledge, attitudes and beliefs of the traveler regarding travel vaccines, vaccine-preventable diseases, and other factors. Further research is required to increase travelers' awareness of the need for pretravel vaccination and then to translate that awareness into positive attitudes leading to increased travel vaccine uptake.

Vaccination contre l'hépatite A chez l'enfant

Hepatitis A is usually considered as a mild disease and is asymptomatic in more than 80% of children less than 5 years of age. Furthermore, incidence of the disease decreased dramatically in France during the past decades. For these reasons mass routine vaccination is not required in our country. However, infected children shed the virus in the community and are responsible for secondary cases, sometimes severe. That is why, despite the cost and the absence of reimbursement of the vaccine, immunisation against hepatitis A is recommended in children attending health-care institutions, in children with chronic liver disease and in those travelling in endemic areas. Prophylaxis around an index case is the main problem because non-specific immunoglobulins, although recommended, are not available in France for this indication. Vaccination in the few days following exposition has been reported to be efficient in household contacts and small communities, including nurseries. This strategy is recommended by the British Advisory Board within the 7 days following exposition, but not in France. However, it can be proposed to the family by paediatricians.