Before starting this article I would just like to affirm I am a strong proponent of vaccines.
Born in Belfast in 1973, I got vaccinated against a total of 5 diseases as a child, diptheria, pertussis, tetanus, polio and TB. (I just missed being vaccinated against smallpox!, which was discontinued the year previously)
Nowadays the childhood schedule in New Zealand includes routine vaccination against 11 infections with further vaccines funded for special circumstances (Click here for NZ immunisation schedule). Immunisation schedules in some other countries have even more.
I wonder how many infections my grandchildren will get vaccinated against?
There may a few reasons why the number of vaccines will not go up too much more during our lifetimes.
- Ease of creating a vaccine: Viruses and bacterial toxins are generally the easiest to vaccinate against. After that it gets harder. It may be that most of the diseases that are easy to create effective vaccines against now have vaccines.
- Cost Effectiveness: All vaccines are generally introduced on the basis of their cost-effectiveness, however their continuation on the schedule may not necessarily take into account the current prevalence of disease. It could also be argued more from a philosophical point of view, that any health intervention that is life-saving is ultimately not cost-effective, as the healthcare costs are simply pushed into elderly care. (Health economics are incredibly complex….)
- Time require to develop a vaccine: The time required to develop and trial a vaccine runs into many years (and hundreds of millions of dollars), with no guarantee of success or the vaccine being included on immunisation schedules at the end of it.
- Cultural oppostion to vaccines: As the number of vaccines on the schedule increases it may be that opponents of vaccination (for whatever reason) may become more numerous.
We may see the odd vaccine drop off the schedule eventually, polio being the obvious candidate if global eradication is eventually acheived, and I am sure there may be a few new vaccines added over the next generation. There are currently about 300 vaccines in the research and development phase, including auto-immune and cancer vaccines. But how many of these vaccines will make it to the market?
However I do not envisage children getting vaccinated against 50 different diseases during our lifetimes. Famous last words…