As the readers look over the topics covered in this special focus issue on vaccine adjuvants, we hope that they will be struck by the impressive growth of clinical and experimental data in the past 4 years since the last issue of Expert Review of Vaccines on this theme. This issue makes clear the persistence and proliferation of investigators working around the generally good idea that ‘adjuvare’ embodies. Unfortunately, there is a danger that modern adjuvants will, for the wrong reasons, not reach their full potential as a component of routine immunization. The problem with adjuvants parallels a similar unscientific public resistance to traditional licensed vaccines that has led to the modern tragedy of preventable deaths through rejection of vaccines recommended by public health experts. The same type of sentiment threatens the use of modern adjuvants.
I have a light-hearted parable, perhaps told with rose-colored glasses, to suggest a way out. In the past, some of us working in adjuvant science became users of Macs, for they embodied a really good concept. Despite strong and contrary public dogma of the time including the ubiquitous anti-Mac IT staff, we knew that Macs were better than PCs and had compelling benefits. One resistance tactic we used was to hide behind the necessity of our Macs to run FACs machines. IT staff were intimidated by this biologically based machine that ate cells and spit out incomprehensible inkblots that they vaguely suspected might provide the basis for the next Nobel prize or blockbuster. Resisting public pressure, and finding the marketing message was in tune with our experience, we hung on. Today, the Mac loyalists are vindicated … even my IT guys all have iPads! Mac made a good product and made their case.
And where is the lesson for the adjuvant field? Today, adjuvant scientists and developers should endeavor to produce a very good product. Adjuvanted products need to be supported by data on the mechanism of action, by clear evidence for their added value and by compelling safety data. At the discovery level, there are many hints that reactogenicity due to adjuvants can be muted or even eliminated, and we should continue to search for the ‘perfect’ adjuvant that enhances immunity without local or systemic reactions. Based on a compendium of good data for products that meet important medical needs, vaccine developers and public health officials should then promote the use of licensed products with modern adjuvants. The vaccine field is fortunate to have a spokesman in Paul Offit, who sets an example as a balanced and eloquent advocate for the public health benefit of vaccines. Adjuvanted vaccines hold great promise. When adjuvanted products meet the criteria outlined above, having passed through regulatory review and having demonstrated benefit, then the data and evidence deserve a similarly strong public voice to promote their use to help the good idea reach its potential.
The articles encompassed within this issue document important clinical data on modern adjuvants and illustrate areas requiring development including: understanding of the mechanisms of action of both empirically discovered adjuvants and those produced on the basis of ligand-mediated activation of specific immune sensors; the production of adjuvants inducing cell-mediated immunity against a number of epidemic-causing pathogens, such as HIV; the role of adjuvants in cancer vaccine development; and investigation into combination approaches and novel delivery strategies.
This special focus issue provides a chance to collect and summarize important recent data, and thus benefits the reader with the freshness provided by these data sets, often lost in the time lag of textbook publication. Thanks go to the editors who worked very hard to bring this issue about and to the contributors who fit the writing of these articles into their busy schedules. This issue also provides an opportunity to remember a great colleague, Stanley Hem, who recently passed away. Fittingly, he had a highly cited review of alum published in our last special focus issue on vaccine adjuvants and we are thankful for his life and work Citation[1].
Financial & competing interests disclosure
Gregory M Glenn is Chief Medical Officer at Novavax, MD, USA. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.
Reference
- Hem SL, Hogenesch H. Relationship between physical and chemical properties of aluminum-containing adjuvants and immunopotentiation. Expert Rev. Vaccines6(5), 685–698 (2007).