Use of cotton rats for preclinical evaluation of measles vaccines

The continued prevalence and medical impact of measles worldwide has create d interest in the development of new generations of measles vaccines. Monke ys can be used for preclinical testing of these vaccines. However, a more p ractical and less expensive animal model is highly desirable, particularly for initial vaccine development and evaluation. Cotton rats have been shown to support the replication of different strains of measles virus (MV), and thus may be useful for these purposes, To test this concept, the immunogen icity and protective efficacy of two standard (Moraten and trivalent measle s, mumps, rubella) and four experimental (two recombinant ALVAC, one ISCOM subunit and live attenuated Edmonston-Zagreb) MV vaccines were evaluated in naive cotton rats, and cotton rats with passively acquired MV-specific neu tralizing serum antibodies. All of the test vaccines were immunogenic and p rotected naive animals from pulmonary infection and viral dissemination. Ho wever, under the conditions utilized, only the Edmonston-Zagreb vaccine pro vided such protection to animals with significant levels of passively acqui red MV-specific neutralizing antibodies. The results of these tests and the potential of using cotton rats as an animal model for preliminary testing of MV vaccines are discussed. (C) 2000 Elsevier Science Ltd. All rights res erved.