[Catch-up vaccination of worldwide newcoming (adopted, refugee or migrant) children in France]

In France, international adoption includes around to 90,000 children since 1980 and near 300,000 immigrant children were counted in 2008. This population is heterogeneous, according to age and country of origin, and its large number. It is not easy to completely and surely assess the vaccine status of the child. Due to a great variability of individual situations, it is not possible to have systematic and unchangeable rules. This article aims to give an update of catch-up vaccination of internationally adopted or refugee or migrant children in France. The vaccination status of a child who recently arrived in France is complex and has to be adapted to his country of origin. Some of them were never vaccinated whereas the vaccine status of others is uncertain or unknown. Three parameters have to be considered: the age of the child, the country of origin, and sometimes serology in the case of doubts of his vaccine status. Catch-up vaccination of foreign children has to be adapted to French vaccine recommendations, as a reference, and to vaccines already administered to the child.

[Current events in vaccination]

The annual meeting of the Infectious Disease Society of America (IDSA) ; which brought together nearly 5000 participants from over 80 countries in Vancouver, Canada, October 21 to 24, 2010 ; provided a review of the influenza (H1N1) 2009 pandemic, evaluated vaccination programmes and presented new vaccines under development. With 12,500 deaths in the United States in 2009-2010, the influenza (H1N1) 2009 pandemic was actually less deadly than the seasonal flu. But it essentially hit the young, and the toll calculated in years of life lost is high. The monovalent vaccines, whether live attenuated or inactivated with or without adjuvants, were well tolerated in toddlers, children, adults and pregnant women. In order to protect infants against pertussis, family members are urged to get their booster shots. The introduction of the 13-valent Pneumococcal conjugated vaccine in the beginning of 2010 may solve - but for how long ? - the problem of serotype replacement, responsible for the re-increasing incidence of invasive Pneumococcal infections observed in countries that had introduced the 7-valent vaccine. The efficacy of a rotavirus vaccine has been confirmed, with a reduction in hospitalization in the United States and a reduction in gastroenteritis-related deaths in Mexico. In the United States, vaccination of pre-adolescents against human papillomavirus (HPV) has not resulted in any specific undesirable effects. Routine vaccination against chicken pox, recommended since 1995, has not had an impact on the evolution of the incidence of shingles. Vaccination against shingles, recommended in the United States for subjects 60 years and over, shows an effectiveness of 55 %, according to a cohort study (Kaiser Permanente, Southern California). Although some propose the development of personalized vaccines according to individual genetic characteristics, the priority remains with increasing vaccine coverage, not only in infants but also in adults and the elderly. Vaccine calendars that cover a whole lifetime should be promoted, since the vaccination of adults and seniors is a determining factor of good health at all ages.

[Varicella vaccine]

A live virus attenuated vaccine was developed from the OKA strain (isolated from vesicles in the OKA child, 3 years of age, presenting with a benign varicella). The vaccine was completed after 11 propagation at 34 degrees C on HELF cells. The vaccine is a lyophilized preparation of a live attenuated virus, obtained by propagation of the virus in MRC-5 human diploid cell culture, titering between 1500 and 5000 cfu (colony forming unit per milliliter). This attenuated virus, contrary to the wild virus, is thermo-sensitive (39 degrees C). The rate of seroconversion after administration of one vaccine dose in healthy children, from 12 months to 12 years of age, ranges from 93% to 100% (Table 1). In controlled studies, the efficiency for the prevention of varicella in children reaches at least 85% with a 2-4 years follow-up. The prevention of severe forms is at least 95%.