Two-dose measles vaccination schedules.

As measles continues to exact a high toll on infant mortality, particularly in developing countries, optimal strategies for the control of the disease are under discussion. As part of this debate, the place of 2-dose measles immunization schedules is reviewed regarding their potential as a strategy to improve measles control. To date, WHO has not recommended the use of a 2-dose schedule. A number of industrialized countries have already adopted a 2-dose schedule, often choosing to administer measles vaccine in the same injection as mumps and rubella vaccines. However, at present not enough is known about such schedules in developing countries to make global recommendations. Further research should include randomized controlled trials of early 2-dose schedules to investigate both technical and epidemiological issues such as the effect of blunting immunity and the duration of antibody. Long-term safety should be determined through studies of adequate size. Programmes already using 2-dose schedules are encouraged to evaluate their impact on disease incidence, cost, vaccine usage, and effect on coverage. Until further evaluation is complete, a high and timely coverage with one dose of measles vaccine in all areas remains the first priority for all immunization programmes.