摘要：Recently in New Zealand there have been outbreaks of measles and
pertussis every six and five years respectively. A model has been
used to compare the dynamics of these diseases, and to determine the
optimum ages at which children should be vaccinated against them.
Whereas measles could be eliminated by giving the second vaccination
at five years instead of eleven, it is difficult to devise a
practical scheme that would eliminate pertussis. It is then
necessary to consider vaccination schemes in the light of the
age-structure of future epidemics as well as their timing.
