The burden of acute respiratory infection due to measles in developing countries and the potential impact of measles vaccine.

Measles is a major cause of acute lower respiratory infection (ALRI) in developing countries. Hospital and community-based studies of ALRI have found that measles accounts for 6%-21% of the morbidity and 8%-93% of the mortality due to ALRI. Although live attenuated measles vaccine is one of the most effective vaccines in use today, measles has not been controlled in many parts of the world, primarily because the levels of vaccine coverage required to interrupt measles transmission have not been achieved. In addition, in some areas, a large percentage of cases of measles occur in infants who are younger than the age recommended for vaccination. Recent studies suggest that the Edmonston-Zagreb measles vaccine may be more immunogenic than other vaccine strains in young infants. A substantial proportion of ALRI could be prevented by increasing measles vaccine coverage and by the use of particular vaccine strains in younger children.