A review of measles vaccine failure in developing countries

Abstract

Summary Measles is one of the major preventable childhood killer diseases in developing countries. Annually about 70 million cases occur worldwide. Measles vaccine has been developed over decades to prevent and control measles. Although national immunization programsprevent over 80 million cases of measles and 4.5 million deaths annu- ally, it is estimated that over 30 million cases and 875,000 d~ths still occur every yeat. High transmksion of measles despite high coverage with I-dose measles vaccine has been reported in some developing countries. Some of the reasons for vaccine failure in developing countries include; poor seroconversion, questionable potency of vaccines due to problem with cold chain that ultimately affect the quality of vaccine and waning immunity. To prevent outbreaks of measles in developing countries, there is needfor second dose of measles vaccine to take care of vaccine failures. This measure is necessary even in countries where there is high coverage with one dose of measles vaccine. The relevant International Agencies need to develop second dose measles vaccination policiesfor developing countries as obtains in some developed countries. Key words: Measles vaccine, failure, developing countries