Towards Rational Vaccine Design

A recent study published in Immunology Letters, the official journal of the European Federation of Immunological Societies (EFIS), describes strategies for selective priming of B cells using various adjuvants. Randolph Noelle and colleagues from Dartmouth Medical School in Lebanon, USA show that certain adjuvants can induce antigen specific memory B cells, in the absence of induction of plasma cells. This is an important fundamental immunological observation as it suggests that memory B cells can arise independently of long-lived plasma cells, which is also interesting from a vaccination perspective.

The immune system recognizes vaccine agents as foreign, destroys them, and “remembers” them. When the virulent version of an agent comes along, the immune system is thus prepared to respond. This long term immunity relies heavily upon the generation of so called B cells, which will generate antibodies that will bind to pathogens and mark them for destruction. Specifically, almost all vaccine formulations induce two types of B-cells: memory B cells and antibody producing B-cells called plasma cells.

Adjuvants, agents which modify the effect of other agents while having few, if any direct effects when given by themselves, are many times used to modify (in this case augment) the effects that a vaccine has on disease resistance. However, the reasons why certain vaccine adjuvants are more or less effective at inducing immune responses often remains unclear.

“This article provides a very exciting new insight because it seems to change the traditional textbook paradigm on relationship between plasma cells and memory B cells”, said Vaclav Horejsi, the Editor-in-Chief of the EFIS journal.

In addition to being scientifically very interesting, the discovery may have important practical consequences in vaccinology as they suggest that memory B cell can be induced during vaccination without the recipient having to mount a strong primary antibody response during immunization. “While perhaps not immediately practicable, this study will have a contribution to the rational development of adjuvants for use in vaccination”, according to immunologist James Brewer from the University of Strathclyde in Glasgow, UK in his commentary published volume 109, issue 2 of Immunology Letters.