Seroconversions in unvaccinated infants : further evidence for subclinical measles from vaccine trials in Niakhar, Senegal.
Background Increases in measles antibodies without rash-illnesses have been documented in previously vaccinated children exposed to measles cases.
The phenomenon has been incompletely evaluated in young unvaccinated infants with immunity of maternal origin.
Methods Monthly cohorts of newborns were prospectively randomized to vaccine and placebo control groups during a trial of high-titre vaccines in Niakhar, Senegal.
Measles antibodies were assayed in blood samples of enrolled children collected at 5 months old, when controls received a placebo injection, and at 10 months, when the placebo group was given measles vaccine.
Intensive prospective surveillance for measles was conducted throughout the trial.
Results One-fifth (n=53) of the placebo controls seroconverted, with known exposure to a measles case in only three of them.
None of the seroconverters developed a measles-like rash.
Sixteen-fold or greater increases in titres were noted in about one-quarter of them.
Compared with placebo controls who did not seroconvert, seroconverters were more likely to have had exposure to a measles case and to travel, more likely to be boys than girls, and had significantly lower baseline antibody titres.
Measles was endemic in the study area throughout the trial.
Seroconversions did not adversely effect subsequent nutritional indices or mortality. (...)
Mots-clés Pascal : Rougeole, Virose, Infection, Sérologie, Séropositivité, Anticorps, Vaccination, Epidémiologie, Forme clinique, Enfant, Homme, Sénégal, Afrique
Mots-clés Pascal anglais : Measles, Viral disease, Infection, Serology, Seropositivity, Antibody, Vaccination, Epidemiology, Clinical form, Child, Human, Senegal, Africa
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0148195
Code Inist : 002B05C02J. Création : 16/11/1999.