Abstract: The present invention relates to nucleic acids comprising: (a) sequences of a replication competent transmissible gastroenteritis virus (TGEV), which sequences encode a TGEV replicase under the control of expression regulatory sequences so that expression of the replicase in a cell containing the nucleic acid will initiate replication of the nucleic acid and thus increase the number of nucleic acids in the cell; and (b) sequences encoding one or more proteins of a different virus wherein the one or more proteins are capable of associating into a virus-like particle (VLP) that does not contain any infectious nucleic acid. The present invention further relates to vectors, virus particles and host cells comprising these nucleic acids as well as their use for the preparation of vaccines, specifically for the preparation of vaccines.

Abstract: A method for the detection of minority genomes in virus quasispecies using DNA microchips. The method makes it possible to detect minority genomes, more particularly minority memory genomes, in a nucleic acids population of a virus quasispecie, which are present in a population of less than 50%, containing at least one mutation relative to the majority genomes of the quasispecie. The method involves the following steps: a) extracting the nucleic acid of the virus quasispecie form a sample susceptible of containing the virus quasispecie; b) amplifying at least one fragment of the nucleic acid of the virus quasispecie, and c) detecting and analyzing the existence of minority genomes using DNA microchip-base techniques. The method can be used in genetic diagnosis of viral diseases.