The present invention relates to vaccine compositions comprising attenuated strain of Tilapia Lake Virus (TiLV) for protecting tilapia fish against infection by (TiLV). The invention also relates to methods for using the vaccines to protect tilapines from TiLV-induced disease.

A method to prepare recombinant influenza viruses comprising a mutant M2 protein which has a deletion of two or more residues in the cytoplasmic tail and is attenuated in vivo, is provided, as well the resulting virus and vaccines with the virus.

Provided herein are cells, methods, kits and articles of manufacture, including those related to assessing the potency of viral vectors. The present disclosure relates to a method for screening for potency of a viral vector, including vectors which encode recombinant receptors that contain an extracellular antigen-binding domain and an intracellular signaling domain, such as a chimeric antigen receptor (CAR). The methods include assessing potency of a viral vector based on a detectable or measurable expression or activity of a reporter molecule(s) that are responsive to a signal through the intracellular signaling region of the T cell receptor e.g., recombinant receptor.