Pérez Schael I, Rojas Mazzei A M, Flores J
Instituto de Biomedicina, UCV-MSAS, Caracas, Venezuela.
Acta Cient Venez. 1991;42(6):296-312.
The significance of rotavirus as an agent in acute diarrhea in children is well established, and much effort has been made towards the development of a vaccine for its prevention. In Venezuela, between the years 1985 and 1991, 3 different strategies for a rotavirus vaccine testing in children have been evaluated. The first consisted on the utilization of simian rotavirus (RRV-ser 3). This vaccine was found to be innocuous, immunogenic and induced homotypic protection. However, because there are 4 epidemiologically important virus serotypes, a new strategy was evaluated. This used a reassortant virus that had 10 genes from the simian viral genome and 1 from the human viral genome, that designated the serotype. Three different reassortants with serotypes 1, 2 and 4 were obtained. The studies with these new viruses demonstrated them to be innocuous but, apparently, the immunogenicity was lower when the four serotypes were mixed in a quadrivalent vaccine than when they were applied individually, or in bivalent vaccines. In consequence, a third strategy was tested, using a virus, M37, isolated from a newborn child. This has the advantage with respect to others, that it is from human origin. However the levels of seroresponse to this virus were no very different from those obtained with the quadrivalent vaccine. At the present time, higher concentrations of the quadrivalent vaccine, in 3 doses, are being applied. We hope to develop ta greater response in these children. If this is achieved, we will then evaluate the efficacy of the vaccine to determine the protection against most severe cases of rotavirus diarrhea.
轮状病毒作为儿童急性腹泻病原体的重要性已得到充分证实，人们为开发预防该病毒的疫苗付出了诸多努力。在委内瑞拉，1985年至1991年间评估了3种在儿童中测试轮状病毒疫苗的不同策略。第一种策略是使用猿猴轮状病毒（RRV-ser 3）。该疫苗被发现无害、具有免疫原性并能诱导同型保护。然而，由于有4种在流行病学上重要的病毒血清型，因此评估了一种新策略。此策略使用了一种重组病毒，其具有来自猿猴病毒基因组的10个基因和来自人类病毒基因组的1个基因，后者决定血清型。获得了三种不同血清型（1、2和4型）的重组病毒。对这些新病毒的研究表明它们无害，但显然，当这四种血清型混合在一种四价疫苗中时，其免疫原性低于单独使用或制成二价疫苗时。因此，测试了第三种策略，即使用从一名新生儿分离出的M37病毒。相对于其他病毒，它的优势在于源自人类。然而，对这种病毒的血清反应水平与四价疫苗所获得的水平并无太大差异。目前，正在应用更高浓度的三剂四价疫苗。我们希望在这些儿童中产生更大的反应。如果实现这一点，我们将随后评估该疫苗的疗效，以确定其对轮状病毒腹泻最严重病例的保护作用。
