Screening Blood Donors for High Titre Antibody to Herpes Varicella‐Zoster

Abstract

As a method of increasing supplies of varicella-zoster immunoglobulin, semi-automated screening of blood donors for high titre complement-fixing antibody was initiated. This was compared with the previously used method of donor selection based on a history of varicella or zoster in the past 6 months. About one-third of the "history" donors had titres of greater than or equal to 1 in 64 and generally these levels declined rapidly. In contrast, although only 1.1% of donors in random screening had antibody titres greater than or equal to 1 in 64, these levels usually remained high during repeated donation, enabling the production of pools entirely composed of high titre plasma packs.