International measles incidence and immunization coverage

Robert Hall, Damien Jolley

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15 Citations (Scopus)

Abstract

Abstract Measles is exquisitely sensitive to immunization programs. We investigated the decline in measles incidence after immunization with 1 or 2 doses of measles-containing vaccine (MCV), with or without supplementary immunization activities (SIAs). Using data from the World Health Organization, we modeled the impact of measles immunization using a negative binomial regression model. All countries offer measles immunization, and 192 of 193 countries offer a second dose of MCV (MCV2), using either a routine second dose, SIAs, or both. The incidence of measles fell from a median of 70.9 cases/100,000/year when coverage with a first dose of MCV (MCV1) was in the range of 0 a??39 to a median of .9 cases/100,000/year when MCV1 coverage was 90 a??100 , in both cases with no MCV2. Further reductions followed the introduction of MCV2 and SIAs. Modeling showed that each 1 increase in MCV1 coverage was followed by a 2.0 decrease in incidence in the same and following years (95 confidence interval [CI], 2.0 a??1.9 , and 2.1 a??1.9 , respectively). For a second dose, a rise of 1 in MCV2 coverage was followed by a decrease in measles incidence by .4 (95 CI, .3 a??.5 ) in the same year and .3 (95 CI, .2 a??.5 ) in the following year. SIAs were followed by decreases of measles incidence by 40.3 (95 CI, 46.3 a??33.8 ) in the same year and 45.2 (95 CI, 51.1 a??48.7 ) in the following year. A herd immunity effect was demonstrated with MCV1 coverage of >80 , and SIAs are an extraordinarily effective strategy for measles control.
Original languageEnglish
Pages (from-to)S158 - S163
Number of pages6
JournalThe Journal of Infectious Diseases
Volume204
Issue numberSuppl 1
DOIs
Publication statusPublished - 2011

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