** Shares of biopharma company Icosavax Inc ICVX.O jump
58% to $6.63, set for biggest ever one-day pct gain
** ICVX among top pct gainers across U.S. exchanges
** Company late Tuesday provided data from early-stage trial
of its experimental RSV vaccine IVX-121, which showed
neutralizing antibody response against RSV lasted for at least
six months after one dose
** Respiratory syncytial virus (RSV) is a common, contagious
virus that causes infections of the respiratory tract
** Cowen and Co says durability data in older adults
compares favorably to RSV vaccines from Pfizer Inc PFE.N and
GSK GSK.L
** Despite session gains, Icosavax shares down ~73.6% YTD
(Reporting by Mariam E Sunny)
((Mariam.ESunny@thomsonreuters.com))