Persistence of yellow fever vaccine-induced antibodies after solid organ transplantation.

Immunization using live attenuated vaccines represents a contra-indication after solid organ transplantation (SOT): consequently, transplant candidates planning to travel in countries where yellow fever is endemic should be vaccinated prior to transplantation. The persistence of yellow fever vaccine-induced antibodies after transplantation has not been studied yet. We measured yellow-fever neutralizing antibodies in 53 SOT recipients vaccinated prior to transplantation (including 29 kidney recipients and 18 liver recipients). All but one (98%) had protective titers of antibodies after a median duration of 3 years (min.: 0.8, max.: 21) after transplantation. The median antibody level was 40 U/L (interquartile range: 40-80). For the 46 patients with a known or estimated date of vaccination, yellow-fever antibodies were still detectable after a median time of 13 years (range: 2-32 years) post-immunization. Our data suggest there is long-term persistence of antibodies to yellow fever in SOT recipients who have been vaccinated prior to transplantation.

[Long term persistence of yellow fever neutralising antibodies in elderly persons]. / Persistance à long terme des anticorps neutralisants de la fièvre jaune chez les personnes âgées de 60 ans et plus.

The activity of the yellow fever virus is reemerging in areas without recent transmission history, such as northern Argentina and Paraguay, and persists in an epidemic mode in other countries in Africa and Latin America. Thus more and more travelers are at risk of being exposed to this disease. The population is becoming older, sometimes suffering from multiple pathologies. Moreover, the risk of serious adverse events associated with live-attenuated YF17D vaccine, such as multiple organ failure (YEL-AVD), reaches 1/50,000 vaccines in people over 65 versus 1/200,000 in the general population. We analyzed, in a retrospective study, the results of neutralizing antibody titers against yellow fever in people aged 60 and older, who had been previously vaccinated against yellow fever and had visited the International Vaccination Centre of the Institut Pasteur between January 2005 and February 2009. In this population of 84 persons (median age 69 years), the date of the last vaccination was always more than 10 years: it was precisely known in 68 subjects and alleged in 16 subjects. The median time since the previous vaccination was 14 years, with a maximum of 60 years. The indications of serology were: immunosuppressive therapy (19% of cases), cancer (32%), hemopathy (10.7%), HIV infection (3.6%), chronic hepatitis/chronic renal failure/dialysis (2.4%), autoimmune diseases (2.4%), and in 29.8% of cases, age alone was the indication of serology. The antibody titer was at a protective level in 95.2% of cases. The four individuals with negative serology had no formal documented proof of a previous vaccination against yellow fever. This serological study was able to show a persistent protective antibody titer, after a previous vaccination, even going back 60 years, allowing patients to travel in a yellow-fever endemic area despite a contraindication, and without requiring any vaccine booster.

[Aortocoronary bypass. Development of technics and indications over a 10-year period]. / Pontages aorto-coronaires. Evolution des techniques et des indications sur une période de 10 ans.

During the 1973-1983 period considerable changes have taken place in the techniques and indications of coronary bypass. In a homogeneous series of 3095 patients operated upon by the same group, changes in techniques have been: the introduction in routine coronary bypass of the membrane oxygenator which provides optimal biological conditions and the prolonged circulatory assistance so necessary to high risk patients, and the application to coronary bypass of microsurgical techniques enabling surgeons to perform multiple anastomoses on small vessels easily and safely. Changes in indications have been characterized by a progressive decrease in operations on patients with one-vessel lesions and normal left ventricular function to the benefit of those with multiple-vessel lesions and altered left ventricular function. As a result, the complete revascularization rate and the number of anastomoses have increased continuously. These two categories of changes have not modified the overall in-patient mortality rate, but there has been a significant increase in peri-operative necrosis.