  In this paper, we analyze the temporal evolution of the age-dependent force
of infection and incidence of rubella, after the introduction of a very
specific vaccination programme in a previously nonvaccinated population where
rubella was in endemic steady state. We deduce an integral equation for the
age-dependent force of infection, which depends on a number of parameters that
can be estimated from the force of infection in steady state prior to the
vaccination program. We present the results of our simulations, which are
compared with observed data. We also examine the influence of contact patterns
among members of a community on the age-dependent intensity of transmission of
rubella and on the results of vaccination strategies. As an example of the
theory proposed, we calculate the effects of vaccination strategies for four
communities from Caieiras (Brazil), Huixquilucan (Mexico), Finland and the
United Kingdom. The results for each community differ considerably according to
the distinct intensity and pattern of transmission in the absence of
vaccination. We conclude that this simple vaccination program is not very
efficient (very slow) in the goal of eradicating the disease. This gives
support to a mixed strategy, proposed by Massad et al., accepted and
implemented by the government of the State of Sao Paulo, Brazil.
