The invention relates to the field of coronaviruses and diagnosis, therapeutic use, and vaccines derived therefrom. The invention provides replicative coronaviruses and virus-like particles (VLPs) from which large parts of their genome are (at least functionally) deleted without abolishing their replicative capacities. The deletion preferably results in at least a functional deletion in that the corresponding gene is not or is only partly expressed wherein the resulting gene product is dysfunctional or at least functionally distinct from a corresponding wild-type gene product. One result seen with VLPs provided with deletions as provided herein is that the deleted VLP, albeit capable of replication in vitro and in vivo, are generally well attenuated, in that they do not cause disease in the target host, making them very suitable for therapeutic use, such as a delivery vehicle for genes and other cargo (wherein specific targeting may be provided as well when desired), and for use as a vaccine, being attenuated while carrying important immunogenic determinants that help elicit an immune response.