Preliminary Tests of a Highly Attenuated Measles Vaccine

Abstract

During the next few months, the immuni¬ zation campaign will be extended to a fur¬ ther 100,000 to 200,000 children in 3 southern republics of the U.S.S.R. The fol¬ lowing schedule will be adopted: Firstly, measles vaccine will be given subcutaneously, and at the same time 0.5 ml. of -globulin will be given intramuscularly. After 30 to 40 days all children, irrespective of their clinical response to the first vaccination, will be revaccinated with a vaccine containing the same dose of virus and in addition the live mumps vaccine developed by Smorodintsev and Klyachko. With this regimen we ob¬ serve the simultaneous development of a high state of immunity against 2 important children's diseases-measles and mumps. SummaryPreliminary results are presented of clini¬ cal, immunological, and epidemiological re¬ sponse to live measles vaccines propagated in chick embryo fibroblasts and in cultures of guinea pig kidney cells. The vaccine was first given along with -globulin at another site. Those children showing no clinical symptoms were revaccinated 30 to 40 days later using vaccine alone. Using this regimen intensive febrile reactions were reduced from 25% or 30% to 5%. Serological conversion was virtually complete.A number of investigators 1-4 have demonstrated the effectiveness of live, attenuated measles viruses in immunizing susceptible children against measles. However, the vaccinations caused a relatively high rate of generally mild reactions. A febrile response occurred in approximately 70%-80% of the children, reaching 105 F or above in some cases. A slight, measles-like rash was also observed in approximately 50%. McCrumb et al.,5 Reilly et al.,6 and Stokes et al.7 have recently demonstrated that these reactions could be reduced by the simultaneous use of \g=g\-globulin. out \g=g\-globulin and yet will cause the development of measles antibodies. We have therefore attempted to further modify the Edmonston strain of measles virus.1,2 This paper is a preliminary report on results obtained by testing our experimental measles strain in children. Materials and MethodsVirus Strain.-The Edmonston strain described previously* was passed 77 additional times in chicken embryo tissue culture, and a series of virus pools were prepared in our laboratory for the following studies. The titers of these pools ranged from 102S to IO*-6 TCIDso per 0.2 ml. The methods used for safety and potency testing have been re¬ ported.1 The dose per child was 0.2 ml. of vaccine administered subcutaneously.Serological Tests.-A minimum of 2 serum specimens was obtained from each child; 1 sample prior to vaccination, and the other 3 to 6 weeks after. The complement fixation, as well as neu¬ tralization, tests were employed throughout the study. Both test procedures have been described.1 However, FL amnion, instead of human heart, cells were used in most instances for the neutralization tests.Downloaded From: http://archpedi.jamanetwork.com/ by a University of British Columbia Library User on 06/17/2015

Thermostability of attenuated measles virus vaccine in Pakistan

“…The test was achieved using the WHO method for potency testing of Measles vaccine. 10,11 The first reading of the microtitration plate for the presence of a cytopathic effect in the form of syncytia (multinucleated giant cells) was observed using an inverted microscope and recording started on the 4 th day, the second reading was taken on the 7 th day and the final reading was made on the 9 th day. During reading each well was examined for specific cytopathic effect (CPE).…”

Shift of the Distribution of Age in Patients with Otosclerosis

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Evaluation of live attenuated measles vaccines prepared in human diploid cells for reimmunization

“…Whether attenuated measles virus retains a stable immunogenicity after repeated passages in CEF is a very important facet of the production of vaccines. With the Edmonston strain, further attenuation was not detected at its 53rd passage in CEF (Gaffe & Laurence, 1961) and only became evident after over 90 passages (Schwarz, 1962). The Beckenham 20 strain, a derivative of the Edmonston B virus, was exceptionally in being suspected to have reverted to full virulence during some of its passages in CEF and the related vaccine was therefore withdrawn from the market leading (Article 1969).…”