Prevalence of Measles Antibodies in São José do Rio Preto, São Paulo, Brazil: A serological survey model

Abstract

Measles is an acute and highly contagious but vaccine-preventable infectious disease. Despite years of being considered eliminated, decreased vaccination rates have produced virus reemergence in several countries, including Brazil. Measles can be controlled through immunization programs, through which aim to achieve 95% coverage with two doses of the vaccine. Measles can also be controlled if suspected cases can be properly identified in order to contain outbreaks. This cross-sectional study determined the prevalence of measles antibodies and their correlation with rubella antibodies (resulting from the combination vaccine used in Brazil's public immunization program) in individuals aged higher 10 years old in São José do Rio preto, São paulo State, Brazil, participants of a prospective cohort of arbovirosis surveillance before virus reemergence in the country. Our findings presented that 32.9% of individuals aged 10-40 years old had not antibodies against measles; 39.3% of total individuals with documented evidence of measles vaccination did not have anti-measles IgG, though only 20.2% of individuals with documented evidence of rubella vaccination lacked anti-rubella IgG. Besides, the most of measles cases reported in the city, following the virus spreading in the country, occurred especially in groups defined by us as susceptible. Because the combination MMR vaccine is part of Brazil's national vaccine schedule, the possible reasons for this relatively high rate of seronegativity need to be investigated further, once that it reflects outbreak risk.

Number of doses of Measles-Mumps-Rubella vaccine applied in Brazil before and during the COVID-19 pandemic

“…The MMR vaccine, produced from live attenuated measles, rubella and mumps viruses, is available free of charge in Brazil and recommended for routine vaccination at 12 months and 9 years of age [ 9 ]. Even with the freely available vaccine distributed throughout the national territory, in 2018, two years after receiving measles-free certification for the elimination of virus in the Americas [ 10 ], 10,346 cases of the disease were confirmed in Brazil, resulting in the loss of certification as a “measles virus-free country” [ 11 ].…”

Risk of Absence of Measles Antibody in Healthcare Personnel and Efficacy of Booster Vaccination

“…Differences in seropositivity between males and females also support our hypothesis. In studies conducted in other countries, there was no difference in the measles seroprevalence according to sex [ 16 , 17 , 18 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. However, in our study, m-IgG seropositive rate in males was higher than that of females.…”

Estudo soroepidemiológico do sarampo em populações residentes na Região Metropolitana de Belém, estado do Pará, Brasil, 2016 a 2018

“…A frequência geral de indivíduos imunes, assim como em todas as faixas etárias do estudo, apresentou-se abaixo dos 95% preconizados pelo MS do Brasil. Esse fato demonstra que parte da população pode não ter recebido o reforço, conforme orientação do MS. Estofolete et al 22 , ao descreverem a soroprevalência para o sarampo em indivíduos maiores de 10 anos de idade em São José de Rio Preto, no estado de São Paulo, encontraram percentuais semelhantes (84,2%) na população de 10 a 40 anos de idade.…”