An RSV vaccine candidate for adults aged 60 and older has received breakthrough designation from the FDA, according to a press release. The vaccine candidate, mRNA-1345, received the designation based on findings from the ConquerRSV phase 3 trial that showed it was 83.7% effective against RSV-associated lower respiratory tract disease, which researchers defined by the presence of two or more symptoms. The vaccine’s efficacy against RSV-associated lower respiratory tract disease as defined by three or more symptoms was 82.4%. The vaccine was generally well tolerated, with no significant safety signals reported. According to the press release, most adverse reactions so far to mRNA-1345 were mild or moderate and most often included injection site pain, fatigue, headache, myalgia, and arthralgia. The overall rate of grade 3 or greater systemic adverse reactions was 4.0% for mRNA-1345 and 2.8% for placebo.
