Typhoid Vaccine Trials in Nepal

Last year, American and Nepali public health specialists successfully tested a new intramuscular typhoid vaccine. The epidemiologists reported in the New England Journal of Medicine that the prevalence of disease among those vaccinated was one fourth that of those who had not been vaccinated. It might well be (and one hopes) that this new vaccine will prove itself by saving lives and health of thousands of Nepalis.

The intramuscular vaccine tested in the study requires only one dose, has few side effects and is 75 per cent effective. An oral vaccine tested in Chile and other countries requires three doses and also has no side effects. However, its effectiveness is 60 to 70 per cent.

Since the preliminary reports point to a major breakthrough, it is important to ask a few questions in the context of Nepali public health. If the research was done for the sole purpose of testing the vaccine, then the project was successful. But if the purpose was to initiate a programme of intramuscular typhoid vaccine in Nepal, then the matter needs to be discussed.

The intramuscular method of vaccination requires an adequate number of trained personnel for country-wide coverage, plus syringes, vials and special facilities for distribution and storage. Given the scarcity of health professionals and equipment, the best one could do would be to run ad hoc immunization campaigns.

If past experience is any indication, in Nepal and elsewhere in the developing world, the tendency is to go for latest, high-tech interventions that look impressive on paper but are secondary in application, especially in village systems. Top-down health planning inevitably leads one up this path.

The oral vaccine could be distributed through the village health worker, who is presently quite under-utilized due to a lack of drugs and an influential social role. The three doses can be easily administered by the health worker within his precinct at required intervals. This also provides an opportunity to monitor the effectiveness of the vaccine. Even if the oral vaccine is only 60 per cent effective, might it not be preferable to the injectable vaccine because of its much broader reach?

It might well be that after thorough study the intramuscular method will be found preferable. The issue has been raised here mainly to illustrate a larger issue for public health planners. The best available method in a developed country or in Kathmandu may not be the most advisable one for a hill district. In any event, whichever vaccine is found suitable must immediately be put to use before the next typhoid epidemic engulfs us.