Summary of the situation

Abstract

Globally, after years of declining measles vaccination coverage, measles cases in 2022 increased by 18% and deaths increased by 43% worldwide (as compared to 2021). According to a new report by the World Health Organization (WHO) and the United States Centers for Disease Control and Prevention (CDC), the estimated number of measles cases is 9 million and the number of deaths stands at 136,000 (most of them children) (1). According to the provisional monthly measles and rubella surveillance data, published by WHO until January 2024 1 , in 2022, 369,195 suspected cases of measles were reported in 166 Member States of the 6 WHO Regions, of which 171,156 (46%) were classified as measles (includes laboratory-confirmed cases, clinical, or epidemiological criteria). In 2023, 534,672 suspected measles cases were reported in 169 Member States, of which 280,933 (53%) were classified as measles (2). This represents a 64% increase in confirmed cases in 2023 as compared to 2022. On 8 February and 20 October 2023, the Pan American Health Organization / World Health Organization (PAHO/WHO) warned about the decrease in coverage of the first and second doses of the measles, rubella, and mumps vaccine (MMR1 and MMR2) and the occurrence of measles cases in countries in the Region of the Americas (3,4). Immunization coverage in the Region of the Americas (5) An analysis of the range of coverage for the MMR1 and MMR2 vaccines for 2022 in the countries of the Americas Region is presented below. Regarding the application of the first MMR1 dose, 25% (10/40) of the countries in the Region report a very high level of coverage (≥ to 95%), 22.5% (9/40) a high level of coverage (90-94%), 30% (12/40) a medium level (80-89%), and 22.5% (9/40) a low level of coverage (< 80%) (Figure 1). In relation to the application of the second MMR2 dose, only 17.5% of countries (7/40) report a very high level of coverage, while 53% of countries (21/40) report a low level of coverage Given the challenges related to the persistence of low coverage of the first and second doses of the vaccine against measles, rubella, and mumps (MMR1 and MMR2), the increase in measles cases globally, and the occurrence of imported cases in countries in the Region of the Americas, the Pan American Health Organization / World Health Organization (PAHO/WHO) urges Member States to continue with activities to increase and maintain adequate vaccination coverage against measles, rubella, and mumps and reiterates that vaccination, epidemiological surveillance, and preparation of rapid response to measles and rubella outbreaks constitute the three major strategies to annually monitor and reverify the interruption of endemic transmission of these viruses.