Methods of producing a pathogen with reduced replicative fitness are disclosed, as are attenuated pathogens produced using the methods. In particular examples, the method includes deoptimizing one or more codons in a coding sequence, thereby reducing the replicative fitness of the pathogen. Methods of using the attenuated pathogens as immunogenic compositions are also disclosed.

In certain embodiments, the disclosure relates to the polynucleotide sequences of respiratory syncytial virus (RSV). In certain embodiments, the disclosure relates to isolated or recombinant nucleic acids and polypeptides comprising desirable nucleic acid sequences and mutations disclosed herein. In certain embodiments, isolated or recombinant RSV comprising the nucleic acids and polypeptides disclosed herein (e.g., attenuated recombinant RSV) are also provided, as are immunogenic compositions including such nucleic acids, polypeptides, and RSV genomes that are suitable for use as vaccines. Attenuated or killed RSV containing these nucleic acids and mutation in the form of copied nucleic acids (e.g., cDNAs) are also contemplated.

Provided is a polynucleotide encoding a respiratory syncytial virus (RSV) variant having an attenuated phenotype comprising a modified RSV genome or antigenome that encodes a mutant RSV protein P that differs from a parental RSV protein P at one or more amino acid residues. In some embodiments, the polynucleotide is recombinant. The invention also relates to methods of vaccinating an animal with the RSV variant or a pharmaceutical composition containing the RSV variant or inducing an immune response by administering the RSV variant to an animal, and further relates to methods of producing an RSV variant vaccine. In some embodiments, the animal is a human.

Methods of producing a pathogen with reduced replicative fitness are disclosed, as are attenuated pathogens produced using the methods. In particular examples, the method includes deoptimizing one or more codons in a coding sequence, thereby reducing the replicative fitness of the pathogen. Methods of using the attenuated pathogens as immunogenic compositions are also disclosed.

The current disclosure relates to methods, compositions and kits for detecting modified adenosine in a target RNA molecule. Aspects relate to a method for detecting modified adenosine in a target ribonucleic acid (RNA) comprising contacting the target RNA with an adenosine deaminase enzyme (adenosine deaminase, RNA-specific) to generate a target RNA with deaminated adenosines and sequencing the target RNA with deaminated adenosines; wherein the modified adenosine is detected when the nucleotide sequence includes adenosine within a m6A motif.

This disclosure relates to chimeric respiratory syncytial virus (RSV), live attenuated vaccine and immunogenic compositions, and methods of use. In certain embodiments, the chimeric respiratory syncytial virus has a mutated gene pattern encoding an RSV F protein having M at position 79, R at position 191, K at position 357, and/or Y at position 371.

Recombinant, live, attenuated viruses of the Pneumoviridae family are disclosed that include a baculovirus GP64 envelope glycoprotein or variant or fragment thereof and a respiratory syncytial virus (RSV) F protein variant or fragment thereof. Also disclosed are polynucleotides encoding the virus as well as pharmaceutical compositions and vaccines containing the virus. In addition, methods of producing and using each of the above compositions are also disclosed.

Described herein are RSV polynucleotide sequences that make use of multiple codons that are containing silent nucleotide substitutions engineered in multiple locations in the genome, wherein the substitutions introduce a numerous synonymous codons into the genome. Due to the large number of defects involved, the attenuated viruses disclosed herein provide a means of producing attenuated, live vaccines against RSV.

Methods of producing a pathogen with reduced replicative fitness are disclosed, as are attenuated pathogens produced using the methods. In particular examples, the method includes deoptimizing one or more codons in a coding sequence, thereby reducing the replicative fitness of the pathogen. Methods of using the attenuated pathogens as immunogenic compositions are also disclosed.

Provided herein are novel recombinant respiratory syncytial viruses (RSV) having an attenuated phenotype that contain mutations in the M2-2 open reading frame that interfere with the expression of the M2-2 protein. The M2-2 mutations may be present in combination with mutations at other loci. Using methods described herein, combinations of mutations are provided to achieve desired levels of attenuation. The recombinant RSV strains described here are suitable for use as live-attenuated RSV vaccines. Also provided are polynucleotide sequences of the described viruses, as well as methods for producing and using the viruses.