Vaccination against the major infectious diseases

The reputation of vaccination rests on a 200-year-old history of success ag ainst major infectious diseases. That success has led to the doctrine of 'f or each disease, a vaccine'. Although some diseases have proved frustrating , this doctrine carries considerable truth. However, when one reviews the v accines now available it is apparent that most successes have been obtained when the microbe has a bacteremic or viremic phase during which it is susc eptible to the action of neutralizing antibodies, and before replication in the particular organ to which it is tropic. Poliomyelitis and infections b y capsulated bacteria are examples where vaccination has worked efficiently . However, some success has also been achieved against agents replicating o n respiratory or gastrointestinal mucosae. Influenza, pertussis and rotavir us vaccines are examples of such agents, against which it has been possible to induce immune responses acting locally as well as systemically. In addi tion, when bacteria produce disease through exotoxins, purification and che mical or genetic inactivation of those toxins has yielded highly efficaciou s vaccines. Control of intracellular pathogens has not been achieved, excep t partly with the BCG vaccine against tuberculosis, and modern efforts are directed towards pathogens against which cellular immune responses are crit ical. In general, two achievements have been crucial to the success of vacc ines: the induction of long-lasting immunological memory in individuals and the stimulation of a herd immunity that enhances control of infectious dis eases in populations. (C) 1999 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.