Heat stability of lyophilized influenza vaccine formulations.

aNot applicable.
bNot detectable; detection limit = ∼1 μg/ml (equal to 0.1% recovery).
Residual moisture content (RMC) of lyophilized vaccine formulations was determined directly after lyophilization. Glass transition temperatures (Tg) were calculated from RMCs. Lyophilized vaccines were stored for one month at 37°C and 60°C. Recovery of HA1 and antigenicity was determined after reconstitution and is shown as a percentage of initial recovery after lyophilization. Data represent mean ± SD; n = 3.