Infants and young children are at increased risk for respiratory syncytial virus (RSV) infections because of their maturing immune system and lack of prior exposure to RSV. A genetically stable live-attenuated RSV vaccine (from the US National Institutes of Health) has been shown to be safe and immunogenic in RSV-seronegative children in Phase I studies. A Phase II study is ongoing to evaluate vaccine virus transmissibility to close contacts of study participants (VAD00014 study). Study VAD00004 will be initiated as part of the Phase III development of the RSVt vaccine. The objective of this study is RSVt clinical efficacy, while also further investigating the safety and immunogenicity of the RSVt vaccine in a global context. Vaccine efficacy against lower respiratory tract disease (LRTD) and upper respiratory tract disease (URTD) will be assessed separately, which will provide evidence of protection against RSV respiratory disease if efficacy against both LRTD and URTD is demonstrated.

INVESTED is a multi-site trial comparing high-dose (60 μg per vaccine viral strain) trivalent influenza vaccine to standard-dose (15 μg per viral strain) quadrivalent influenza vaccination for up to three influenza seasons in high-risk cardiovascular disease patients with a history of myocardial infarction in the previous 12 months OR history of heart failure hospitalization in the previous 24 months. Subjects will be randomly assigned to receive either the high-dose or standard-dose vaccine.