| Abstract: | We detail aspects of measles immunization programmes in several countries. Live measles vaccine has been available in Australia for 16 years, yet, in 1981, there were outbreaks of measles in the State of New South Wales (population 5 200 000) which led to 2200 admissions to hospital and five deaths. In response to complaints of "vaccine failure", a survey determined that 22.5% of children with measles seen by general practitioners and 10.3% of those admitted to hospitals had been previously immunized. There was no evidence of waning immunity, and noparticular batch of vaccine was implicated. The vaccine failures are attributed in part to failure of seroconversion in some recipients when immunized at 12 months of age as a result of interference by transplacentally acquired antibodies. As more of the susceptible population is vaccinated, there will be fewer cases of measles, but among these cases will be an increasing proportion of cases occurring in previously vaccinated individuals. The equation to calculate this expected proportion of "vaccine failures" is given. We support the measures to increase immunization compliance. |
