ABSTRACT
Emulsions have been used extensively in immunology and vaccine research for decades. The best-known emulsion is Freund’s adjuvant, which is a water-in-oil emulsion (1). Complete Freund’s, containing mycobacteria, is universally regarded as too toxic for human use, but incomplete Freund’s (lacking mycobacteria) has been used as a potent adjuvant formulation for a diversity of vaccines in more than a million people (2-4). Freund’s incomplete adjuvant is currently being developed for certain human and veterinary vaccines (5). Other vaccines using emulsion technology have been developed and are either licensed or in clinical trials (6-9). An oil-in-water emulsion (MF59) has been developed and manufactured by Novartis, Emeryville, California, U.S.A. It has been studied extensively in animals and is used in a licensed influenza vaccine in Europe (10-12). Prior to the 2004-2005 influenza season, more that 11 million doses had been
administered and the vaccine was proven to be safe. Clinical trials have also recently been conducted with MF59 adjuvanted antigens for cytomegalovirus (13) and HIV (14). Glaxo SmithKline, Brentford, Middlesex, U.K. has developed an oil-in-water emulsion (AS02) that has been used in clinical trials for a malaria vaccine (15-17), melanoma tumor expressing MAG3 protein (18), and hepatitis B (19). This emulsion contains monophosphoryl lipid A and QS-21 as adjuvants.
