A live RSV vaccine with engineered thermostability is ... www.ncbi.nlm.nih.gov/pmc/articles/PMC5187593 Dec 21, 2016 · For determination of nAb titres, 8- to 10-week-old male and female cotton rats at Baylor College of Medicine were sedated and inoculated i.n. with 10 5 FFU of virus in 100 µl of serum-free MEM. On day 42, serum was obtained via the orbital plexus of the cotton rats and stored at -80 °C until analysed as described above.