Live Respiratory Syncytial Virus (RSV) Vaccine Candidate Containing Stabilized Temperature-Sensitivity Mutations Is Highly Attenuated in RSV-Seronegative Infants and Children.
RSVcps2, bearing the stabilized 248 (248s) mutation and the 1030s mutation, contains the following changes relative to MEDI-559: (1) the original 248 mutant assignment of 831L(TTA) was changed to 831L(TTG; change underlined) , (2) the 1030 assignment of asparagine [1321N(AAT)] was changed to lysine [1321K(AAA)] , and (3) the nearby codon 1313S(AGC) was changed to 1313S(TCA) to prevent a second-site mutation that compensated for 1321K(AAA).
Live-Attenuated Respiratory Syncytial Virus Vaccine Candidate With Deletion of RNA Synthesis Regulatory Protein M2-2 is Highly Immunogenic in Children
A major effort has been directed at development of a live-attenuated RSV vaccine to avoid the RSV disease enhancement previously observed with the formalin-inactivated RSV vaccine. Disease enhancement has not been observed with live-attenuated RSV vaccine candidates or replicating vaccine vectors. Important potential advantages of intranasal live-attenuated RSV vaccines include induction of a spectrum of protective and immunoregulatory mucosal and systemic immune responses
Determining the outcomes of interventions to prevent respiratory syncytial virus disease in children: what to measure?
Respiratory syncytial virus (RSV) is the most common cause of viral acute lower respiratory tract illness (LRTI) in young children, and a major cause of hospital admissions and health-care utilisation globally. Substantial efforts have been made to develop RSV vaccines and vaccine-like monoclonal antibodies to prevent acute RSV LRTI. Prevention of acute disease could improve long-term lung health, with potential effects on wheezing, asthma, and chronic lung disease. This Personal View describes assessments that should be initiated during clinical trials and continued after licensure to fully evaluate the effect of RSV preventive interventions.