TRAVEL VACCINES - A REVIEW OF CURRENT THINKING

More controversial aspects of the administration of vaccines are discu ssed with particular emphasis on the uncertainties surrounding measure ment and significance of immunological markers in predicting efficacy. New areas of vaccine development are highlighted, particularly the im portance of greater understanding of the gut immune mechanisms which p romise oral delivery routes for a variety of immunogens. Emphasis is l aid on the requirement for expert administration of intradermal inject ion if protection is to be reliable. Several new vaccines have been in troduced recently and relevant issues relating to typhoid, cholera and hepatitis A vaccines are discussed. New possibilities for immunisatio n against travellers diarrhoea are appraised. The required frequency o f booster doses is discussed for several vaccines where it is found th at long term protection has often not been well researched. This is no where better demonstrated than with hepatitis B. Finally less commonly used vaccines are discussed and the importance of assessing true risk before deciding on use is emphasized.