hCD46 receptor is not required for measles vaccine Schwarz strain replication in vivo: Type-I IFN is the species barrier in mice.

Measles virus has been successfully attenuated on chicken embryo cells to obtain a highly efficient and safe live attenuated vaccine, administered thus far to billions of children. Measles virus attenuation has long been described to involve a modification of cellular tropism with the use of human CD46 ubiquitous receptor. Nevertheless, the use of this receptor in vivo is not obvious. In this study we use four different mouse models to decipher the respective part of hCD46 receptor and type-I interferon response in measles host restriction. We observed that only type-I interferon restricts viral replication of attenuated MV Schwarz strain in mice, independently of the presence of hCD46 receptor. By comparing measles virus immunogenicity in the different models, we confirmed that there was no impact on the absence of this receptor on the immune response. Therefore, we propose to simplify the mouse model.

[Live attenuated measles vaccine as a potential multivalent pediatric vaccination vector]. / Utilisation potentielle du vaccin vivant atténué contre la rougeole comme vecteur de vaccination pédiatrique multivalent.

Live attenuated RNA viruses make highly efficient vaccines. Among them, measles virus (MV) vaccine has been given to a very large number of children and shown to be highly efficacious and safe. MV vaccine induces a life-long immunity after a single or two low-dose injections. It is easily produced on a large scale in most countries and can be distributed at low cost. Reversion to pathogenicity has never been observed with this vaccine. For all these characteristics, MV vaccine might be a very promising vector to immunize children against both measles and other infectious agents such as HIV or flaviviruses, in the developing world. In this article, we describe recent data demonstrating the capacity of recombinant Schwarz measles virus to express proteins from Human Immunodeficiency or West Nile viruses, and to induce specific immune responses able, in the case of West Nile virus, to protect from an experimental challenge.