Effect of storage temperature on the stability of Lassa virus complement-fixing antigen

Inactivated Lassa virus complement-fixing antigen is normally prepared as a wet frozen antigen, and shipped in dry ice from the Center for Disease Control, Atlanta, Georgia, USA, to other laboratories not equipped for handling live Lassa virus. However, with this antigen there is a considerable loss of potency during shipping. In the search for a more stable antigen, inactivated Lassa antigen was lyophilized and subjected to different storage temperatures. Lyophilization did not significantly affect the CF titre, and the lyophilized antigen remained stable for 15 and 28 days at 25 degrees C and 4 degrees C, respectively.